Showing posts with label CFML. Show all posts
Showing posts with label CFML. Show all posts

Wednesday, 14 September 2022

CFML: working MySQL datasource in Application.cfc (this is just a note-to-self/Google)

G'day:

No content in this one, I just want something I can find when I search for how to config a MySQL datasource in Application.cfc in ColdFusion. I always forget/lose the code, and I can never find anything on Google. It'd be marvellous of Adobe would document this stuff, but it's a bit much to expect of them, I guess.

component {

    setsettings()
    loadDatasources()

    private void function setSettings() {
        this.name = "app1"
    }

    private void function loadDataSources() {
        this.datasources["dsn1"] = {
            driver = "mysql",
            class = "com.mysql.jdbc.Driver",
            url = "jdbc:mysql://database.backend:3306/"
                & "#server.system.environment.MARIADB_DATABASE#"
                & "?useUnicode=true&characterEncoding=UTF-8",
            username = server.system.environment.MARIADB_USER,
            password = server.system.environment.MARIADB_PASSWORD
        }
        this.datasource = "dsn1"
    }
}

The bit I always forget is the class bit, so I end up with an error along these lines:

No driver or URL found.

java.sql.SQLException: No driver or URL found.
 at coldfusion.server.j2ee.sql.pool.JDBCPool.createPhysicalConnection(JDBCPool.java:586)
 at coldfusion.server.j2ee.sql.pool.ConnectionRunner$RunnableConnection.run(ConnectionRunner.java:67)
 at java.base/java.lang.Thread.run(Thread.java:834)

This is also on GitHub @ Application.cfc.

Righto.

--
Adam

Thursday, 8 September 2022

CFML: speaking of application scope proxies

G'day:

OK so you probably weren't talking about application scope proxies, but I was in my previous article: CFML: looking at how CFWheels messes up a loop. In that article I look at some very uncontrolled (and buggy: hence the article) application-scope access. And I made the observation that one should never access the application scope in one's application code, other than via a proxy.

This got me thinking. How hard is it actually to write one of these proxies that handles the locking for you, keeps yer code testable, and minimises the chance of having shared scope errors? All whilst minimising locking boilerplace and stuff.

Turns out it's pretty simple to get a proof of concept together (code on Github @ ApplicationScopeProxy.cfc / ApplicationScopeProxyTest.cfc):

component {

    public function init(struct applicationScope) {
        variables.applicationScope = arguments.applicationScope
    }

    public function set(required string key, required any value) {
        lock scope="application" type="exclusive" timeout=5 throwontimeout=true {
            "variables.applicationScope.#key#" = value
        }
    }

    public any function get(required string key) {
        lock scope="application" type="readonly" timeout=5 throwontimeout=true {
            if (isDefined("variables.applicationScope.#key#")) {
                return structGet("variables.applicationScope.#key#")
            }
            throw(type="ApplicationScopeProxy.KeyNotFoundException", message="Key [#key#] not found in application scope");
        }
    }

    public void function withReadOnlyLock(required function task) {
        lock scope="application" type="readonly" timeout=5 throwontimeout=true {
            task()
        }
    }

    public void function withExclusiveLock(required function task) {
        lock scope="application" type="exclusive" timeout=5 throwontimeout=true {
            task()
        }
    }
}

And it's got superficial first-pass red/green tests:

import testbox.system.BaseSpec
import cfml.cfmlLanguage.scopes.ApplicationScopeProxy

component extends=BaseSpec {

    function run() {
        describe("Tests of ApplicationScopeProxy", () => {
            describe("Tests for the set method", () => {
                it("sets a variable", () => {
                    testApp = {}
                    proxy = new ApplicationScopeProxy(testApp)
                    proxy.set("testKey", "TEST_VALUE")

                    expect(testApp).toHaveKey("testKey")
                    expect(testApp.testKey).toBe("TEST_VALUE")
                })

                it("sets a variable with a deep path", () => {
                    testApp = {}
                    proxy = new ApplicationScopeProxy(testApp)
                    proxy.set("one.two.three", "TEST_VALUE")

                    expect(testApp).toHaveKey("one")
                    expect(testApp.one.two.three).toBe("TEST_VALUE")
                })
            })

            describe("Tests for the get method", () => {
                it("gets a variable", () => {
                    testApp = {testKey = "TEST_VALUE"}
                    proxy = new ApplicationScopeProxy(testApp)
                    result = proxy.get("testKey")

                    expect(result).toBe("TEST_VALUE")
                })

                it("gets a variable with a deep path", () => {
                    testApp = {one={two={three = "TEST_VALUE"}}}
                    proxy = new ApplicationScopeProxy(testApp)
                    result = proxy.get("one.two.three", "TEST_VALUE")

                    expect(result).toBe("TEST_VALUE")
                })

                it("throws an exeption if the key is not found", () => {
                    testApp = {}
                    proxy = new ApplicationScopeProxy(testApp)

                    expect(() => {
                        proxy.get("one.two.three", "TEST_VALUE")
                    }).toThrow(
                        type = "ApplicationScopeProxy.KeyNotFoundException",
                        regex = "Key \[one\.two\.three\] not found in application scope"
                    )
                })
            })

            describe("Tests for the withReadOnlyLock method", () => {
                it("waits until it can get a lock before continuing", () => {
                    proxy = new ApplicationScopeProxy({})

                    telemetry = ["test start"]
                    t1 = runAsync(() => {
                        telemetry.append("t1 started")
                        lock scope="application" type="exclusive" timeout=5 throwontimeout=true {
                            sleep(1000)
                        }
                        telemetry.append("t1 ended")
                    })
                    t2 = runAsync(() => {
                        telemetry.append("t2 started")

                        proxy.withReadOnlyLock(() => {
                            telemetry.append("withReadOnlyLock ran")
                        })

                        telemetry.append("t2 ended")
                    })
                    t1.get()
                    t2.get()

                    lockTelemetry = telemetry.find("withReadOnlyLock ran")
                    t1EndTelemetry = telemetry.find("t1 ended")
                    expect(lockTelemetry).toBeGt(t1EndTelemetry, serializeJson(telemetry))
                })
            })

            describe("Tests for the withExclusiveLock method", () => {
                it("waits until it can get a lock before continuing", () => {
                    proxy = new ApplicationScopeProxy({})

                    telemetry = ["test start"]
                    t1 = runAsync(() => {
                        telemetry.append("t1 started")
                        lock scope="application" type="readlonly" timeout=5 throwontimeout=true {
                            sleep(1000)
                        }
                        telemetry.append("t1 ended")
                    })
                    t2 = runAsync(() => {
                        telemetry.append("t2 started")

                        proxy.withExclusiveLock(() => {
                            telemetry.append("withExclusiveLock ran")
                        })

                        telemetry.append("t2 ended")
                    })
                    t1.get()
                    t2.get()

                    lockTelemetry = telemetry.find("withExclusiveLock ran")
                    t1EndTelemetry = telemetry.find("t1 ended")
                    expect(lockTelemetry).toBeGt(t1EndTelemetry, serializeJson(telemetry))
                })
            })
        })
    }
}

The tests kinda summarise its usage, but there's four methods (five including constructor):

  • Constructor: pass in the scope from the application-boot code (from the DI config or just in onApplicationStart etc). This way even the proxy is uncoupled from the scope. It also aids testing, which you'll've noticed in the tests.
  • set - sets a value in the scope at the location of the specified key. The key can be a dotted-path, and that will be unpacked into substructs. Is run in an exclusive lock.
  • get - as above, but gets it back out again. Is run in a read-only lock.
  • withReadOnlyLock - to avoid race conditions like in the CFWheels code, this takes a block of code and runs it all in a read-only lock. Good for multiple accesses to the application scope that rely on the state not being changed between each access.
  • withExclusiveLock - same as above, except with an exclusive lock. This would handly situations where code is reading and writing to the scope, and needs to be run as an atom before other accesses try to act on the data themselves.

This is just a proof of concept I knocked together in about 1hr without giving too much thought to it (the best way to write code to present to the public as if I know what I'm doing ;-)). There is some room for improvement, obvs:

  • It's not for the methods themselves to set the timeout / throwontimeout values on the locks. I just set those for the sake of expediency. A real-world implementation would likely pass those with each call, and probably optionally fall back to values set by init, or just the default for lock (if there is one? I think maybe not, for timeout).
  • If the returned value is a complex object, then it'll still be prone to race conditions as it'll just be a reference to the underlying shared value. So one would either need to advise to use duplicate when fetching the value, or make it an option on the get, or have a getCopy method too.
  • Having methods like exists, delete, etc would be handy too.
  • Maybe some mechanism to pass in a callback that receives variables.applicationScope as an argument, to do more complex stuff, and the implementation of that just ensures the lock is made?

There'd be plenty of options. The good thing with TDD and incremental delivery, is that one can just deliver what's needed now, and worry about the rest later.

What CFWheels needs now is that withExclusiveLock method, I think…

Righto.

--
Adam

Sunday, 4 September 2022

CFML: invokeImplicitAccessor on CFCs

G'day:

I noticed this yesterday when I was writing my "Kotlin: the next morning learning Kotlin stuff" article. I was looking into how Kotlin handles accessor methods on properties, and remembered CFML had a similar bit of functionality, and quickly revisited it by way of comparison. Whilst looking into it, I noticed that pretty much no-one has mentioned it too much, and it's not even mentioned in the appropriate place in Adobe's on CFML reference for cfcomponent. They only mention it on CFC Implicit notation, somewhat amusingly using code they have clearly lifted from this blog (their example code mentions my son by name). The article they lifted it from is about the original variant of the functionality: "invokeImplicitAccessor is quite cool. Although has some odd quirks". CFDocs mentions it in passing in their cfcomponent docs, but don't really explain it. Lucee doesn't yet support this functionality (see LDEV-171).

Back in ColdFusion 10, a feature was added to Application.cfc that one could specify this.invokeImplicitAccessor=true. This is poorly documented - no mention of it on the Application.cfc page in the docs for example - but I run through its functionalityin that "invokeImplicitAccessor is quite cool. Although has some odd quirks" I mentioned earlier. I'll not repeat it here. Setting this at application-level was always a poor implementation, as how code behaves should be handled in the code itself, not in some application settings. This implementation renders the functionality pretty much unusable in third-party modules (eg: libs one might install and use from ForgeBox), as it relies on application settings that might not exist. I guess the docs for the lib could say "you need to switch this on in Application.cfc", but even if that works, it's a shit way of going about things. This was raised with Adobe at the time the feature was going into the language, but the leadership of the ColdFusion Team in those days had a habit of not listening to their developer community, because they thought they knew better. Sigh.

Anyhow, they kinda fixed the situation in CF2016; they shifted the setting to be CFC-specific. So in a given CFC one can specify this in the component's properties. Here's a quick example:

//Person.cfc
component invokeImplicitAccessor=true {

    property string firstName;
    property string middleName;
    property string lastName;

    public void function setFirstName(required string value) {
        firstName = value
    }

    public void function setMiddleName(required string value) {
        middleName = value
    }

    public void function setLastName(required string value) {
        lastName = value
    }

    public string function getFullName() {
        return "#firstName# #middleName# #lastName#"
    }
}
// test.cfm
person = new Person()
person.firstName = "Annie"
person.middleName = "Jean"
person.lastName = "Easley"

writeOutput(person.fullName)

Result:

Annie Jean Easley

What's going on? Well it's a syntactical sugar / boilerplate reduction thing. It's just a way of exposing private properties publically without having to pepper getThing / setOtherThing etc throughout one's code. It's like a more thoughtful approach to the fairly wooden synthesised accessors that were already in CFML with the accessors CFC setting, and getter and setter options on the property definition. Those are a bit of an anti-pattern.

Just to demonstrate there's no cheating going on, we can try to access one of the write-only properties directly:

try {
    writeOutput(person.firstName)
} catch(any e) {
    writeOutput(e.message)
}

We have not defined a getter on firstName, so it's not accessible:

Element firstName is undefined in PERSON.

The implementation Adobe have given us here is still far from ideal. If they'd thought things through more, they'd've paid attention to how other languages handle properties' accessor methods, which would be more like this in a CFML-idiomatic sort of way:

property string variables.firstName {
    function get() {
        return firstName
    }
    function set(required string value){
        firstName = value
    }
}

There's no reason they could not have done that. Even if they needed to use the long-form / tag-oriented version of property:

property name="firstName" access="private" type="string" {
    function get() {
        return firstName
    }
    function set(required string value){
        firstName = value
    }
}

I mean that syntactical construct - a statement with a body block - is already supported in CFML. Just not the implementation of this specific functionality.

Anyway. We are where we are, and I figured someone ought to document this functionality. Done.

Righto.

--
Adam

Wednesday, 31 August 2022

CFML: outputting text from within inline Java in CFML

G'day:

I saw an odd question today. Me mate Ray was messing around with the Java integration in ColdFusion (that allows one to write Java code directly in one's CFML code), and asked how to write out content to the screen from within the Java code. IE: the equiv of emiting some text in one's CFML response… it ends up on the client browser "screen" (this is not my wording).

My initial reaction was "isn't the answer System.out.println("G'day Ray!")?". But it's not. System.out writes to stdout. Not the response buffer. In my Docker container if I do that println, I get it in my Docker log, eg:

OK so it's not a dumb question.

I knew the answer would be "stick it in the PageContext's BodyContent", but I had no idea of how to get a reference to that via Java. Especially basically a Java snippet running inside a ColdFusion request. I googled a lot and did not find anything I understood (my Java is shit).

So I cheated. ColdFusion knows how to get the current PageContext: via getPageContext(). I'll just pass that in to my Java code:

Warning

This code runs fine in the version of CF that is installed from the adobecoldfusion/coldfusion2021:latest Docker image, but does not run on a local install of CF (even the "exact same version"). It will give you a The setPageContext method was not found. error. I'm not sure why, but I managed to grab the ear of one of the Adobe bods, and they are actively looking into it. I'll report back when we get an answer on this.

messager = java {

    import javax.servlet.jsp.PageContext;

    public class Outputer {

        PageContext pageContext;

        public void output(String text) throws java.io.IOException {
            this.pageContext.getOut().print(text);
        }

        public void setPageContext(PageContext pageContext) {
            this.pageContext = pageContext;
        }
    }
}

messager.setPageContext(getPageContext())
writeOutput("Before stuff added from Java<br>")
messager.output("G'day Ray!<br>")
writeOutput("After stuff added from Java<br>")

And this works:

Before stuff added from Java
G'day Ray!
After stuff added from Java

I dunno if it's a good way of doing it, but it's "a" way.

I'd still prefer knowing how to get the PageContext directly from the Java code, if anyone knows…?

Righto.

--
Adam

Thursday, 11 August 2022

Lucee: Creating a log file programmatically

G'day:

This will be super short as there's not much to say, I just want to note the code down for posterity, and to cross-reference elsewhere.

We need to create some log files in our application. I knew in ColdFusion one can just create a file ad-hoc, thus:

writeLog(file="anythingYouLike", text="some log message")

However the Lucee docs for writeLog were claiming that the file option was not implemented, and was also deprecated (this has since been rectified in the docs). It actually is implemented, but I was not so sure about the deprecation status. I asked and got no straight answer really. Anyway, the docs now say it's all good, so that's something.

Whilst this works, the log file is not managed by Lucee: it doesn't show up in Lucee Admin, so one cannot set things like log level / file size / file retention etc. This is fine for some situation, but was not fine for us. We need to be able to control the log level.

I had a sniff around, and found org.lucee.cfml.Administrator, and looking some more, found Configure Lucee within your application. From that, I concocted this proof of concept:

local.admin = new Administrator("web", server.system.environment.ADMINPASSWORD)
admin.updateLogSettings(
    name = "AdamTest",
    level = "ERROR",
    appenderClass = "lucee.commons.io.log.log4j2.appender.ResourceAppender",
    layoutClass = "lucee.commons.io.log.log4j2.layout.ClassicLayout",
    appenderArgs = {
        maxfiles = 20,
        maxfilesize = 1073741824
    }
)
writeLog(log="AdamTest", type="ERROR", text="ERROR SHOULD BE LOGGED")
writeLog(log="AdamTest", type="INFO", text="INFO SHOULD NOT BE LOGGED")

And - hurrah - this does exactly what it looks like it does: all the settings are set correctly and respected. Most importantly for us is that the log level works: in this case logging an ERROR works, but any logs at level INFO are not logged. We have some debugging stuff we want to leave log entries in the codebase, but in general set the log to be ERROR so they don't log until we need to do some debugging.

I had to guess at the appenderArgs key values, but on a whim I assumed they'd be the same as the form fields in Lucee admin, and they kinda were:

<input name="custom_3_appender_maxfiles" type="text" class="large" value="0">
<!-- … -->
<input name="custom_3_appender_maxfilesize" type="text" class="large" value="16">

It also shows up in Admin correctly:

Perfect.

And that's all I have to say on this.

Righto.

--
Adam

Monday, 30 May 2022

CFML: Implementing an ObservableScopeAdapter using the Adapter Pattern, Decorator Pattern and Observer Pattern

G'day:

In my last article (A super-quick Observer Pattern implementation in CFML, and I skip TDD. Or do I?), I did what it suggests: I created a very simple observer pattern implementation in CFML.

Why? Well: to copy and paste from that article:

A few days back I was chatting to someone about application-scope-usage, and how to trigger an event when any changes to the application scope took place. I mentioned that the application scope should never be accessed directly in one's application code, and it should be wrapped up in an adapter. And it's easy for one's adapter to trigger events if needs must. An implementation of the Observer Pattern would do the trick here.

I wanted to keep the article brief-ish and on-point, so just focused on one part of it. In this article I'll put that observer service to use in an application scope adapter.

Firstly I need a scope adapter. The interface to this will be the same for any scope, so I'm gonna keep the name generic.

Well: firstly I need some tests to clearly define how the thing should work:

describe("Tests for set method", () => {
    it("sets a key's value in the scope", () => {
        var scopeAdapter = new ScopeAdapter(local)

        scopeAdapter.set("testVariable", "test value")

        expect(local).toHaveKey("testVariable")
        expect(local.testVariable).toBe("test value")
    })
})

describe("Tests for get method", () => {
    it("gets a value from the scope by its key", () => {
        var scopeAdapter = new ScopeAdapter(local)
        var testVariable = "test value"

        var result = scopeAdapter.get("testVariable")

        expect(result).toBe("test value")
    })
})

And a very simple implementation:

component {

    public function init(required struct scope) {
        variables.scope = arguments.scope
    }

    public void function set(required string key, required any value) {
        variables.scope[key] = value
    }

    public any function get(required string key) {
        return variables.scope[key]
    }

}

And that works. In real life before this was production-ready we'd probably want some error-handling around trying to get values that aren't set, and poss something to handle overwriting values etc. But for my purposes here: this will do.

When I first planned the code for this article in my head, the next step was gonna be to initialise the ScopeAdapter with an ObserverService object, and have it fire off some events on set. Then it occurred to me that this is breaking the Single Responsibility Principle a bit. It's not for the general ScopeAdapter to be doing anything other than being an adapter to a scope. So what I'm going to do is to use the Decorator Pattern: I'm going to create a decorator for a ScopeAdapter that is an ObservableScopeAdapter.

I need to back up slightly and do a slight refactor. If I'm using a decorator, then I need to be able to code to an interface, not to an implementation. I can't be having code that takes specifically a cfml.forBlog.applicationScopeAdapter.ScopeAdapter object; I need it to take an implementation of a cfml.forBlog.applicationScopeAdapter.ScopeAdapter interface. This is because when using a decorator, obviously it's no longer the same concrete implementation class. EG: if I have SomeService class, and it takes as one of its constructor parameters a ScopeAdapter object, I can't then initialise it with an ObservableScopeAdapter. One might think this is solved by making ObservableScopeAdapter simply extend ScopeAdapter. This would work, but it's a bit of an anti-pattern, and I discuss this in "Decorator Pattern vs simple inheritance". Instead we provide an interface for both ObservableScopeAdapter and the current ScopeAdapter (which will need to be renamed) to implement, and we make our SomeService take one of those as its argument.

I'm going to rename ScopeAdapter to be GeneralScopeAdapter, and create an interface that it implements called ScopeAdapter. Yay for tests, as I am refactoring here, not just "changing shit". The only new code here is the interface:

interface {
    public void function set(required string key, required any value);
    public any function get(required string key);
}

Now we want our decorator. It will do two things:

  • Hand off any calls to methods in the ScopeAdapter interface to a full implementation of a ScopeAdapter it has been configured with
  • When set is called, it triggers an event that other code can have subscribed to.

"Hang on", you might say "isn't it doing two things, which is still a violation of the SRP?". Not really. It's only implementing the event trigger part. It's delegating the scope-adapting to its dependent GeneralScopeAdapter. Indeed it's not even implementing the event-triggering side of things. It's delegating that to the ObserverService. So the one thing the decorator is implementing is "making the scope access observable". Make sense?

Anyway here are some tests to set our expectations:

import cfml.forBlog.applicationScopeAdapter.GeneralScopeAdapter
import cfml.forBlog.applicationScopeAdapter.ObservableScopeAdapter
import cfml.forBlog.observerService.SimpleObserverService

component extends=Testbox.system.BaseSpec {
    function run() {
        describe("Tests for ObservableScopeAdapter", () => {
            describe("Tests for set method", () => {
                it("functions as a ScopeAdapter when setting a key's value in the scope", () => {
                    // same implementation as above
                })

                it("triggers an event when set is called, which receives the key/value of the set call", () => {
                    var eventLog = []
                    var localScopeAdapter = new GeneralScopeAdapter(local)
                    var observerService = new SimpleObserverService()
                    var observableScopeAdapter = new ObservableScopeAdapter(localScopeAdapter, observerService)

                    observerService.on("scope.set", (event) => {
                        eventLog.append(event)
                    })

                    observableScopeAdapter.set("testVariable", "test value")

                    expect(eventLog).toHaveLength(1)
                    expect(eventLog[1]).toBe({
                        name = "scope.set",
                        data = javaCast("null", ""),
                        detail = {
                            key = "testVariable",
                            value = "test value"
                        }
                    })
                })
            })

            describe("Tests for get method", () => {
                it("functions as a ScopeAdapter when getting a value from the scope by its key", () => {
                    // same implementation as above
                })
            })
        })
    }
}

Notes:

  • I've changed the name of the ObserverService to be SimpleObserverService because I've extracted an interface for that too, and now that is called ObserverService. I didn't need to do this, but I figured it was more balanced, and "one should program to an interface", etc
  • Where I say same implementation as above, it's literally the same implementation as the earlier tests, because I want to test that the decorated implementation still behaves the same.
  • data is data passed along with the on call, which I am not using here.
  • I had actually neglected to add the feature of trigger to accept details (ie: data) at trigger-time in my initial implementation of BasicObserverService! So I had to add that functionality in. See below.

There's not much to the implementation:

import cfml.forBlog.applicationScopeAdapter.GeneralScopeAdapter
import cfml.forBlog.observerService.ObserverService


component implements=ScopeAdapter {

    public function init(required GeneralScopeAdapter scopeAdapter, ObserverService observerService) {
        variables.scopeAdapter = arguments.scopeAdapter
        variables.observerService = arguments.observerService
    }

    public void function set(required string key, required any value) {
        variables.observerService.trigger("scope.set", arguments)
        variables.scopeAdapter.set(argumentCollection=arguments)
    }

    public any function get(required string key) {
        return variables.scopeAdapter.get(argumentCollection=arguments)
    }

}
  • It implements the same interface as GeneralScopeAdapter, so it can be used anywhere that one of those is required.
  • It's initialised with an underlying GeneralScopeAdapter that does all the scope-adapting, as well as an ObserverService which does all the event handling.
  • get simply proxies to the underlying GeneralScopeAdapter
  • set does that too, but not before triggering an event that it's been called.

As I touched on above, I needed to add a feature to SimpleObservrService so that it passed detail data when triggering an event. Here's the test:

it("passes any extra details as part of the event", () => {
    var observerService = new SimpleObserverService()

    var eventResults = []

    observerService.on("testEvent", (event) => {
        eventResults.append([
            message = "test event handler 1",
            event = event
        ])
    }, {key="value set in handler"})

    observerService.trigger("testEvent", {
        key = "value set by trigger"
    })
    expect(eventResults).toBe([[
        message = "test event handler 1",
        event = {
            name = "testEvent",
            data = {key = "value set in handler"},
            detail = {key = "value set by trigger"}
        }
    ]])
})

That's self-explanatory I think.

And implementation:

public boolean function trigger(required string event, struct detail={}) {
    registerEvent(event)
    return variables.eventRegistry[event].some((eventData) => eventData.handler({
        name = event,
        data = eventData?.data,
        detail = detail
    }) == false)
}

This broke one other test, but in an expected way because it was testing what came back in the event struct, focusing on testing the data part, but it did not expect the new (empty) detail part of the data. All the other tests continued to pass, so I know this change has no unexpected side-effects.


That's it, all working. But how does one wire this into one's app? Well. Any place one currently accesses the application scope (remember the initial requirement was to trigger events when there were changes to the application scope) directly in the app needs to be swapped out for an instance of ObservableScopeAdapter that is adapting the application scope. This can be done easily enough with a DI framework: just inject it into whichever objects formerly accessed the application scope directly, and then use it. Secondly: wherever it is relevant to react to the "scope.set" event: pass in an instance of ObserverService, and attach an event handler to the "scope.set" event that does whatever one needs to. Obviously (?) it needs to be the same instance of ObserverService that the ObservableScopeAdapter is using. Again: super easy with your DI framework.

I realise this section is a bit like this:

Possibly © 9gag.com - I am using it without permission. If you are the copyright owner and wish me to remove this, please let me know.

But it's not really in scope here to explain how dependency injection works. You should already know.


The original question is begging slightly though. It presupposed the situation where there's application-scope access all over the place in an application. In a well-designed app, there simply shouldn't be. Everything ought to be managed by a DI container, and no actual objects ought to know what scope they are in, or care what scope their dependency objects are in. And data values that need to persist for the life of the application should just be in objects that persist for the life of the application, so this should not directly involve the application scope at all.

The same applies for any scope in your CFML code. The only scopes that should generally be relevant to your code are:

  • The variables scope of the CFC the code is in; reflecting the state of the object, or its dependencies, etc
  • The arguments scope of any argument values being passed into your function.
  • The local scope within your function.
  • One is possibly tied to some thread-specific scopes if using cfthread

That's it. If yer accessing any scopes other than those, you should be questioning the design of your application, I think.

The code for this lot is in Github @ /forBlog/applicationScopeAdapter (and its tests) and /forBlog/observerService (and its tests).

Righto.

--
Adam

Tuesday, 17 May 2022

If yer a CFML dev, you should consider financially supporting trycf.com

G'day:

I'll keep this on-point today.

If you are a CFML developer, you will be aware and likely use trycf.com. Whenever I have an issue with some CFML that needs to be demonstrated to someone else; eg: I'm asking for help on Slack or Stack Overflow, or demonstrating an answer to someone else's question: I create a portable / repeatable repro case on trycf.com. I use it to demonstrate bugs and behavioural differences to Adobe or Lucee when both vendors don't give the same result from the same code. I use it every day.

I believe trycf.com is the handiest resource available to CFML developers.

Until now Abram has done all the work to create and maintain trycf.com at his own expense, both financially and with his own time. I reached out to him a coupla days ago wanting to see if I could help-out financially, and he has set up a Patreon page for this very reason. His blurb is:

And the Patreon link is: https://www.patreon.com/trycf/posts.

If you don't want to do a monthly payment, there's also an option to flick him some dosh on a one off basis: https://buy.stripe.com/28o8y6dzHh1bezucMM

Both those links are on the trycf.com homepage.

Go give him some money. If you're the purse-string holder at a company: consider giving him some money on behalf of your company too, to make yourselves better CFML Community participants.

Cheers.


Whilst I'm talking about money, don't forget you perhaps also ought to be supporting Lucee. I wrote about this before: If your company (or yourself) makes money using Lucee… you should throw them a bone. Consider supporting them as well if you haven't already.

Righto.

--
Adam

Friday, 13 May 2022

CFML: adding aroundEach to TinyTestFramework was way easier than I expected

G'day:

I'm still pottering around with my TinyTestFramework. Last night I added beforeEach and afterEach handlers, but then thought about how the hell I could easily implement aroundEach support, and I could only see about 50% of it, so I decided to sleep on it.

After a night's sleep I spent about 30min before work doing a quick spike (read: no tests, just "will this even work?"), and surprisingly it did work. First time. Well except for a coupla typos, but I nailed the logic first time. I'm sorta halfway chuffed by this, sorta halfway worried that even though what I decided would probably work - and it did - I haven't quite got my head around how it works, or even quite what it's doing. So let's blog about that.

This evening after work I ignored my spike, and wrote some tests. This is another TDD lesson: it's OK to do a spike in yer code without tests and stuff to just prove a proof of concept, but then once yer good with that, put it to once side and go back to writing tests. My spike code is in a completely different environment from the environment I'm writing the tests in.

For the tests, I consider a lot of the testing of the hierarchical mechanics of how a describe / it testing framework works has already been tested extensively by the beforeEach tests (see "CFML: Adding beforeEach handlers to my TinyTestFramework. Another exercise in TDD"), and I don't need to restest that. This is the same reason I tested the afterEach stuff quite lightly too ("CFML: for the sake of completeness, here's the afterEach treatment"). In those afterEach tests I just tested the "afterness" of the way it works, which is the only difference in the implementation of afterEach compared to beforeEach. The chief difference being that when there is a hierarchy of afterEach handlers, they are called in the reverse order from equivalent beforeEach handlers.

For aroundEach what I am testing is the "aroundness" of how it works.

Here are the tests:

describe("Tests of aroundEach", () => {
    describe("Tests hierarchical sequencing", () => {
        result = []
        aroundEach((test) => {
            result.append("aroundEach top level before test")
            test()
            result.append("aroundEach top level after test")
        })
        describe("Tests hierarchical sequencing (second level: no aroundEach in this one)", () => {
            describe("Tests hierarchical sequencing (third level)", () => {
                aroundEach((test) => {
                    result.append("aroundEach third level before test")
                    test()
                    result.append("aroundEach third level after test")
                })
                describe("Tests hierarchical sequencing (inner level)", () => {
                    aroundEach((test) => {
                        result.append("aroundEach inner before test")
                        test()
                        result.append("aroundEach inner after test")
                    })
                    
                    it("is the baseline test", ()=> {
                        expect(true).toBeTrue()
                    })

                    it("tests the aroundEach handlers are called in the correct order", ()=> {
                        result.append("tests the aroundEach handlers are called in the correct order")

                        expect(result).toBe([
                            "aroundEach top level before test",
                            "aroundEach third level before test",
                            "aroundEach inner before test",
                            "aroundEach inner after test",
                            "aroundEach third level after test",
                            "aroundEach top level after test",
                            "aroundEach top level before test",
                            "aroundEach third level before test",
                            "aroundEach inner before test",
                            "tests the aroundEach handlers are called in the correct order"
                        ])
                    })
                })
            })
        })
    })

    describe("Tests with beforeEach and afterEach", () => {
        result = []

        afterEach(() => {
            result.append("set by afterEach")
        })

        beforeEach(() => {
            result.append("set by beforeEach")
        })

        aroundEach((test) => {
            result.append("set by aroundEach before test")
            test()
            result.append("set by aroundEach after test")
        })

        it("is the baseline test", ()=> {
            expect(true).toBeTrue()
        })

        it("tests the aroundEach handlers are called in the correct order", ()=> {
            result.append("tests the aroundEach handlers are called in the correct order")

            expect(result).toBe([
                "set by beforeEach",
                "set by aroundEach before test",
                "set by aroundEach after test",
                "set by afterEach",
                "set by beforeEach",
                "set by aroundEach before test",
                "tests the aroundEach handlers are called in the correct order"
            ])
        })
    })
})

So we have:

  • Test how a collection of hierarchical aroundEach handlers work. It looks like a lot of code, but it's just three nested describe blocks each with an aroundEach handler, before finally a test to observe, and a test that does the observation and tests some expectations on same.
  • Test that aroundEach plays nice with beforeEach and afterEach. Again a few lines of code, but pretty simple stuff, and the expectations are pretty clear and straight forward.

Um. OK. So.

The implementation bit is going to be a bit of an anti-climax after that lot. Firstly there's some scaffolding stuff that's obviously needed:

beforeEach = (callback) => {
    tinyTest.contexts.last().beforeEachHandler = callback
},
afterEach = (callback) => {
    tinyTest.contexts.last().afterEachHandler = callback
},
aroundEach = (callback) => {
    tinyTest.contexts.last().aroundEachHandler = callback
},
// ...
beforeEach = tinyTest.beforeEach
afterEach = tinyTest.afterEach
aroundEach = tinyTest.aroundEach

And the implementation is changing this:

it = (string label, function implementation) => {
    tinyTest.inDiv(() => {
        try {
            writeOutput("It #label#: ")

            tinyTest.contexts.each((context) => {
                context.keyExists("beforeEachHandler") ? context.beforeEachHandler() : false
            })

            implementation()

            tinyTest.contexts.reduce((reversedContexts, context) => reversedContexts.prepend(context), []).each((context) => {
                context.keyExists("afterEachHandler") ? context.afterEachHandler() : false
            })

            tinyTest.handlePass()
        } catch (TinyTest e) {
            tinyTest.handleFail()
        } catch (any e) {
            tinyTest.handleError(e)
        }
    })
},

To be this:

decoratedImplementation = tinyTest.contexts
    .filter((context) => context.keyExists("aroundEachHandler"))
    .reduce((reversed, context) => reversed.prepend(context), [])
    .reduce((decorated, context) => () => context.aroundEachHandler(decorated), implementation)

decoratedImplementation()

That's not much code, but it's a wee bit dense, even with putting each step on a separate line. What are we doing:

  • Taking the context collection.
  • Filtering out all the context objects with no aroundEachHandler element. We don't care about those.
  • Flipping the remainder around, as we need to apply them from the one nearest the test to the furthest.
  • Then, starting with the test implementation callback, sequentially pass it to the preceding callback in the hierarchy, if that makes sense. It's kind of a partial-application of each aroundEach callback I guess.
  • Once we've done that, call the returned function.

In effect what I think I am doing is calling a function that calls each aroundEachHandler callback from outermost to innermost, passing it the next handler down as its argument, all the way until the test implementation gets called at the end.

Once that was working, I realised that the filtering step could be applied to the beforeEach and afterEach calls too:

tinyTest.contexts.each((context) => {
    context.keyExists("beforeEachHandler") ? context.beforeEachHandler() : false
})

Becomes:

tinyTest.contexts
    .filter((context) => context.keyExists("beforeEachHandler"))
    .each((context) => context.beforeEachHandler())

And equivalently with afterEach:

tinyTest.contexts.reduce((reversedContexts, context) => reversedContexts.prepend(context), []).each((context) => {
    context.keyExists("afterEachHandler") ? context.afterEachHandler() : false
})

Becomes:

tinyTest.contexts
    .filter((context) => context.keyExists("afterEachHandler"))
    .reduce((reversedContexts, context) => reversedContexts.prepend(context), [])
    .each((context) => context.afterEachHandler())

The usage of ?: didn't sit well with me before, and I like this approach. Of course YMMV.

To copy and paste from last night's article: that's it. I'll add these to the source code:

You know what? I'm quite pleased that the aroundEach handling was so easily solved with just four chained method calls. It seems amazing to me for some reason. I don't mean my code is amazing: I mean the technique is.

Righto.

--
Adam

Thursday, 12 May 2022

CFML: for the sake of completeness, here's the afterEach treatment

G'day:

This immediately follows on from "CFML: Adding beforeEach handlers to my TinyTestFramework. Another exercise in TDD".

Having done the beforeEach implementation for my TinyTestFramework, I reckoned afterEach would be super easy: barely an inconvenience. And indeed it was. Took me about 15min, given most of the logic is the same as for beforeEach.

Here are the tests:

describe("Tests of afterEach", () => {
    it("will not break if an afterEach is not specified for a given describe block", () => {
        expect(true).toBeTrue()
    })
    
    describe("Baseline", () => {
        result = []
        afterEach(() => { 
            result.append("set in afterEach")
        })
        
        it("runs after a test (setup)", () => {
            expect(result).toBe([])
        })
        
        it("runs after a test (test)", () => {
            expect(result).toBe(["set in afterEach"])
        })
    })
    
    describe("Works in a hierarchy (top)", () => {
        result = []

        afterEach(() => { 
            result.append("set in afterEach in outer describe")
        })
        
        describe("Works in a hierarchy (middle)", () => {
            afterEach(() => { 
                result.append("set in afterEach in middle describe")
            })
            
            describe("Works in a hierarchy (inner)", () => {
                afterEach(() => { 
                    result.append("set in afterEach in inner describe")
                })
                
                it("runs all afterEach handlers, from innermost to outermost (setup)", () => {
                    expect(result).toBe([])
                })
                
                it("runs all afterEach handlers, from innermost to outermost (test)", () => {
                    expect(result).toBe([
                        "set in afterEach in inner describe",
                        "set in afterEach in middle describe",
                        "set in afterEach in outer describe"
                    ])
                })
            })
        })
    })
    
    describe("Tests with beforeEach as well", () => {
        result = []
        
        afterEach(() => {
            result.append("set by afterEach")
        })

        beforeEach(() => {
            result.append("set by beforeEach")
        })

        it("is the setup test", () => {
            expect(true).toBeTrue()
        })
        it("tests that both beforeEach and afterEach got run", () => {
            result.append("testing that the preceding setup test had its afterEach called")

            expect(result).toBe([
                "set by beforeEach", // setup test
                "set by afterEach", // setup test
                "set by beforeEach", // this test
                "testing that the preceding setup test had its afterEach called"
            ])
        })
    })
})

These are more superficial than the beforeEach ones because most of it is already tested in those tests. I just test that it's called, works in a hierarchy (no reason why it won't given the implemntation requirements, but it's a belt-n-braces sort of test), and works with a beforeEach in play before. One thing to note is that I need to run a stub/control/setup test before my test of afterEach, because obviously it runs after the test's code, so we can't test what it does with a single test. Hopefully you see what I mean there. That's the chief difference.

The implementation is simple:

beforeEach = (callback) => {
    tinyTest.contexts.last().beforeEachHandler = callback
},
afterEach = (callback) => {
    tinyTest.contexts.last().afterEachHandler = callback
},
it = (string label, function implementation) => {
    tinyTest.inDiv(() => {
        try {
            writeOutput("It #label#: ")

            tinyTest.contexts.each((context) => {
                context.keyExists("beforeEachHandler") ? context.beforeEachHandler() : false
            })

            implementation()

            tinyTest.contexts.reduce((reversedContexts, context) => reversedContexts.prepend(context), []).each((context) => {
                context.keyExists("afterEachHandler") ? context.afterEachHandler() : false
            })

            tinyTest.handlePass()
        } catch (TinyTest e) {
            tinyTest.handleFail()
        } catch (any e) {
            tinyTest.handleError(e)
        }
    })
},
// ...
afterEach = tinyTest.afterEach

That is literally it.

The only non-obvious thing is this:

tinyTest.contexts.reduce((reversedContexts, context) => reversedContexts.prepend(context), []).each((context) => {
    context.keyExists("afterEachHandler") ? context.afterEachHandler() : false
})

Where the beforeEach handlers are run from the outermost to the innermost context, the afterEach ones are run in the reverse order.

That's it. I'll add these to the source code:

Righto.

--
Adam

CFML: Adding beforeEach handlers to my TinyTestFramework. Another exercise in TDD

G'day:

I have to admit I'm not sure where I'm going with this one yet. I dunno how to implement what I'm needing to do, but I'm gonna start with a test and see where I go from there.

Context: I've been messing around with this TinyTestFramework thing for a bit… it's intended to be a test framework one can run in trycf.com, so I need to squeeze it all into one include file, and at the same time make it not seem too rubbish in the coding dept. The current state of affairs is here: tinyTestFramework.cfm, and its tests: testTinyTestFramework.cfm. Runnable here: on trycf.com

The next thing that has piqued my interest for this is to add beforeEach and afterEach handlers in there too. This will be more of a challenge than the recent "add another matcher" carry on I've done.

First test:

describe("Tests of beforeEach", () => {
    result = ""
    beforeEach(() => {
        result = "set in beforeEach handler"
    })
    
    it("was called before the first test in the set", () => {
        expect(result).toBe("set in beforeEach handler")
    })
})

Right and the first implementation doesn't need to be clever. Just make it pass:

tinyTest = {
    // ...
    beforeEach = (callback) => {
        callback()
    }
}

// ...
beforeEach = tinyTest.beforeEach

This passes. Cool.

That's fine but it's a bit daft. My next test needs to check that beforeEach is called before subsequent tests too. To test this, simply setting a string and checking it's set won't be any use: it'll still be set in the second test too. Well: either set or reset… no way to tell. So I'll make things more intelligent (just a bit):

describe("Tests of beforeEach", () => {
    result = []
    beforeEach(() => {
        result.append("beforeEach")
    })
    
    it("was called before the first test in the set", () => {
        result.append("first test")
        
        expect(result).toBe([
            "beforeEach",
            "first test"
        ])
    })
    
    it("was called before the second test in the set", () => {
        result.append("second test")
        
        expect(result).toBe([
            "beforeEach",
            "first test",
            "beforeEach",
            "second test"
        ])
    })
})

Now each time beforeEach is called it will cumulatively affect the result, so we can test that it's being called for each test. Which of course it is not, currently, so the second test fails.

Note: it's important to consider that in the real world having beforeEach cumulatively change data, and having the sequence the tests are being run be significant - eg: we need the first test to be run before the second test for either test to pass - is really bad form. beforeEach should be idempotent. But given it's what we're actually testing here, this is a reasonable way of testing its behaviour, I think.

Right so currently we are running the beforeEach callback straight away:

beforeEach = (callback) => {
    callback()
}

It needs to be cleverer than that, and only be called when the test is run, which occurs inside it:

it = (string label, function implementation) => {
    tinyTest.inDiv(() => 
        try {
            writeOutput("It #label#: ")
            implementation()
            tinyTest.handlePass()
        } catch (TinyTest e) {
            tinyTest.handleFail()
        } catch (any e) {
            tinyTest.handleError(e)
        }
    })
},

The beforeEach call just has to stick the callback somewhere for later. Hrm. OK:

beforeEachHandler = false,
beforeEach = (callback) => {
    tinyTest.beforeEachHandler = callback
},
it = (string label, function implementation) => {
    tinyTest.inDiv(() => {
        try {
            writeOutput("It #label#: ")

            tinyTest.beforeEachHandler()
            
            implementation()

            tinyTest.handlePass()
        } catch (TinyTest e) {
            tinyTest.handleFail()
        } catch (any e) {
            tinyTest.handleError(e)
        }
    })
},

That works. Although it's dangerously fragile, as that's gonna collapse in a heap if I don't have a beforeEach handler set. I've put this test before those other ones:

describe("Tests without beforeEach", () => {
    it("was called before the first test in the set", () => {
        expect(true).toBe(true)
    })
})

And I get:

Tests of TinyTestFramework
Tests without beforeEach
It was called before the first test in the set: Error: [The function [beforeEachHandler] does not exist in the Struct, only the following functions are available: [append, clear, copy, count, delete, duplicate, each, every, filter, find, findKey, findValue, insert, isEmpty, keyArray, keyExists, keyList, keyTranslate, len, map, reduce, some, sort, toJson, update, valueArray].][]
Tests of beforeEach
It was called before the first test in the set: OK
It was called before the second test in the set: OK
Results: [Pass: 2] [Fail: 0] [Error: 1] [Total: 3]

I need a guard statement around the call to the beforeEach handler:

if (isCustomFunction(tinyTest.beforeEachHandler)) {
    tinyTest.beforeEachHandler()
}

That fixed it.

Next I need to check that the beforeEach handler cascades into nested describe blocks. I've a strong feeling this will "just work":

describe("Tests of beforeEach", () => {
    describe("Testing first level implementation", () => {
        // (tests that were already in place now in here)
    })
    describe("Testing cascade from ancestor", () => {
        result = []
        beforeEach(() => {
            result.append("beforeEach in ancestor")
        })
        describe("Child of parent", () => {
            it("was called even though it is in an ancestor describe block", () => {
                result.append("test in descendant")
                
                expect(result).toBe([
                    "beforeEach in ancestor",
                    "test in descendant"
                ])
            })
        })
    })
})

Note that I have shunted the first lot of tests into their own block now. Also: yeah, this already passes, but I think it's a case of coincidence rather than good design. I'll add another test to demonstrate this:

describe("Tests without beforeEach (bottom)", () => {
    result = []
    it("was called after all other tests", () => {
        result.append("test after any beforeEach implementation")
        
        expect(result).toBe([
            "test after any beforeEach implementation"
        ])
    })
})

This code is right at the bottom of the test suite. If I put a writeDump(result) in there, we'll see why:

implentation (sic) error

After I pressed send on this, I noticed the typo in the test and in the dump above. I fixed the test, but can't be arsed fixing the screen cap. Oops.

You might not have noticed, but I had not VARed that result variable: it's being used by all the tests. This was by design so I could test for leakage, and here we have some: tinyTest.beforeEachHandler has been set in the previous describe block, and it's still set in the following one. We can't be having that: we need to contextualise the handlers to only be in-context within their original describe blocks, and its descendants.

I think all I need to do is to get rid of the handler at the end of the describe implementation:

describe = (string label, function testGroup) => {
    tinyTest.inDiv(() => {
        try {
            writeOutput("#label#<br>")
            testGroup()
            tinyTest.beforeEachHandler = false
        } catch (any e) {
            writeOutput("Error: #e.message#<br>")
        }
    })
},

The really seemed easier than I expected it to be. I have a feeling this next step is gonna be trickier though: I need to be able to support multiple sequential handlers, like this:

describe("Multiple sequential handlers", () => {
    beforeEach(() => {
    	result = []
        result.append("beforeEach in outer")
    })
    describe("first descendant of ancestor", () => {
        beforeEach(() => {
            result.append("beforeEach in middle")
        })
        describe("inner descendant of ancestor", () => {
            beforeEach(() => {
                result.append("beforeEach in inner")
            })
            it("calls each beforeEach handler in the hierarchy, from outermost to innermost", () => {
                result.append("test in innermost descendant")
                
                expect(result).toBe([
                    "beforeEach in outer",
                    "beforeEach in middle",
                    "beforeEach in inner",
                    "test in innermost descendant"
                ])
            })
        })
    })
})

Here we have three nested beforeEach handlers. This fails because we're only storing one, which we can see if we do a dump in the test:

I guess we need to chuck these things into an array instead:

describe = (string label, function testGroup) => {
    tinyTest.inDiv(() => {
        try {
            writeOutput("#label#<br>")
            testGroup()
           
        } catch (any e) {
            writeOutput("Error: #e.message#<br>")
        } finally {
            tinyTest.beforeEachHandlers = []
        }
    })
},
beforeEachHandlers = [],
beforeEach = (callback) => {
    tinyTest.beforeEachHandlers.append(callback)
},
it = (string label, function implementation) => {
    tinyTest.inDiv(() => {
        try {
            writeOutput("It #label#: ")

            tinyTest.beforeEachHandlers.each((handler) => {
                handler()
            })

            implementation()

            tinyTest.handlePass()
        } catch (TinyTest e) {
            tinyTest.handleFail()
        } catch (any e) {
            tinyTest.handleError(e)
        }
    })
},

This makes the tests pass, but I know this bit is wrong:

tinyTest.beforeEachHandlers = []

If I have a second test anywhere in that hierarchy, the handlers will have been blown away, and won't run:

describe("Multiple sequential handlers", () => {
    beforeEach(() => {
        result = []
        result.append("beforeEach in outer")
    })
    describe("first descendant of ancestor", () => {
        beforeEach(() => {
            result.append("beforeEach in middle")
        })

        describe("inner descendant of ancestor", () => {
            beforeEach(() => {
                result.append("beforeEach in inner")
            })
            it("calls each beforeEach handler in the hierarchy, from outermost to innermost", () => {
                result.append("test in innermost descendant")

                expect(result).toBe([
                    "beforeEach in outer",
                    "beforeEach in middle",
                    "beforeEach in inner",
                    "test in innermost descendant"
                ])
            })
        })

        it("is a test in the middle of the hierarchy, after the inner describe", () => {
            result.append("test after the inner describe")

            expect(result).toBe([
                "beforeEach in outer",
                "beforeEach in middle",
                "after the inner describe"
            ])
        
        })
        
    })
})

This fails, and a dump shows why:

So I've got no handlers at all (which is correct given my current implementation), but it should still have the "beforeEach in outer" and "beforeEach in middle" handlers for this test. I've deleted too much. Initially I was puzzled why I still had all that stuff in the result still, but then it occurs to me that was the stuff created for the previous test, just with my last "after the inner describe" appended. So that's predictable/"correct" for there being no beforeEach handlers running at all.

I had to think about this a bit. Initially I thought I'd need to concoct some sort of hierarchical data structure to contain the "array" of handlers, but after some thought I think an array is right, it's just that I only need to pop off the last handler, and only if it's the one set in that describe block. Not sure how I'm gonna work that out, but give me a bit…

OK, I think I've got it:

contexts = [],
describe = (string label, function testGroup) => {
    tinyTest.inDiv(() => {
        try {
            writeOutput("#label#<br>")
            tinyTest.contexts.push({})
            testGroup()
           
        } catch (any e) {
            writeOutput("Error: #e.message#<br>")
        } finally {
            tinyTest.contexts.pop()
        }
    })
},
beforeEach = (callback) => {
    tinyTest.contexts.last().beforeEachHandler = callback
},
it = (string label, function implementation) => {
    tinyTest.inDiv(() => {
        try {
            writeOutput("It #label#: ")

            tinyTest.contexts.each((context) => {
                context.keyExists("beforeEachHandler") ? context.beforeEachHandler() : false
            })

            implementation()

            tinyTest.handlePass()
        } catch (TinyTest e) {
            tinyTest.handleFail()
        } catch (any e) {
            tinyTest.handleError(e)
        }
    })
},
  • I maintain an array of contexts.
  • At the beginning of each describe handler I create a context for it - which is just a struct, and push it onto the contexts array.
  • A beforeEach call sticks its handler into the last context struct, which will be the one for the describe that the beforeEach call was made in.
  • When it runs, it iterates over contexts.
  • And if there's a beforeEach handler in a context, then its run.
  • The last thing describe does is to remove its context from the context array.

This means that as each describe block in a hierarchy is run, it "knows" about all the beforeEach handlers created in its ancestors, and during its own run, it adds its own context to that stack. All tests immediately within it, and within any descendant describe blocks will have all the beforeEach handlers down it and including itself. Once it's done, it tidies up after itself, so any subsequently adjacent describe blocks start with on the the their ancestor contexts.

Hopefully one of the code itself, the bulleted list or the narrative paragraph explained what I mean.

As well as the tests I had before this implementation, I added tests for another few scenarios too. Basically any combination / ordering / nesting of describe / it calls I could think of, testing the correct hierarchical sequence of beforeEach handlers was called in the correct order, for the correct test, without interfering with any other test.

describe("Multiple sequential handlers", () => {
    beforeEach(() => {
        result = []
        result.append("beforeEach in outer")
    })
    
    it("is at the top of the hierarchy before any describe", () => {
        result.append("at the top of the hierarchy before any describe")
        
        expect(result).toBe([
            "beforeEach in outer",
            "at the top of the hierarchy before any describe"
        ])
    })
    
    describe("first descendant of ancestor", () => {
        beforeEach(() => {
            result.append("beforeEach in middle")
        })

        it("is a test in the middle of the hierarchy, before the inner describe", () => {
            result.append("test before the inner describe")

            expect(result).toBe([
                "beforeEach in outer",
                "beforeEach in middle",
                "test before the inner describe"
            ])
        })

        describe("inner descendant of ancestor", () => {
            it("is a test in the bottom of the hierarchy, before the inner beforeEach", () => {
                result.append("in the bottom of the hierarchy, before the inner beforeEach")

                expect(result).toBe([
                    "beforeEach in outer",
                    "beforeEach in middle",
                    "in the bottom of the hierarchy, before the inner beforeEach"
                ])
            })
            beforeEach(() => {
                result.append("beforeEach in inner")
            })
            it("calls each beforeEach handler in the hierarchy, from outermost to innermost", () => {
                result.append("test in innermost descendant")

                expect(result).toBe([
                    "beforeEach in outer",
                    "beforeEach in middle",
                    "beforeEach in inner",
                    "test in innermost descendant"
                ])
            })
            it("is another innermost test", () => {
                result.append("is another innermost test")

                expect(result).toBe([
                    "beforeEach in outer",
                    "beforeEach in middle",
                    "beforeEach in inner",
                    "is another innermost test"
                ])
            })
        })

        it("is a test in the middle of the hierarchy, after the inner describe", () => {
            result.append("test after the inner describe")

            expect(result).toBe([
                "beforeEach in outer",
                "beforeEach in middle",
                "test after the inner describe"
            ])
        })
    })
    
    describe("A second describe in the middle tier of the hierarchy", () => {
        beforeEach(() => {
            result.append("beforeEach second middle describe")
        })

        it("is a test in the second describe in the middle tier of the hierarchy", () => {
            result.append("in the second describe in the middle tier of the hierarchy")

            expect(result).toBe([
                "beforeEach in outer",
                "beforeEach second middle describe",
                "in the second describe in the middle tier of the hierarchy"
            ])
        })
    })
    
    it("is at the top of the hierarchy after any describe", () => {
        result.append("at the top of the hierarchy after any describe")
        
        expect(result).toBe([
            "beforeEach in outer",
            "at the top of the hierarchy after any describe"
        ])
    })
})

All are green, and all the other tests are still green as well. Yay for the testing safety-net that TDD provides for one. I think I have implemented beforeEach now. Implementing afterEach is next, but this should be easy, and just really the same as I have done here, with similar tests.

However I will do that separate to this, and I am gonna press "send" on this, have a beer first.

Code:

Oh: the code:test ratio is now 179:713, or around 1:4.

Righto.

--
Adam

Saturday, 7 May 2022

Running CFML code on trycf.com via a remote HTTP request

G'day:

This ended up being more of a rabbit hole than I expected it to be. But in the process I've learned a bit more about curl, PHP, Python, JS (client). And actually CFML too I guess.

I can't even remember why I needed to do this, but it was something to do with testing that TinyTestFramework I've been blathering about recently.

Anyhow, I decided I needed to run some code locally on my PC which would send some code off to trycf.com, run it, and send me back the response. I figured it'd be doable if I worked out what Abram was doing when I click the "Run Code" button on the trycf.com UI. As it turns out it's just an HTTP post, and I could could re-run the curl captured from my browser easily enough:

Yeah I don't care

Thanks, but before you take time to mention it: I know the code blows out to the right. It doesn't matter, no-one's expecting you to read it really, and the blow-out is just just cosmetic shite.

curl 'https://lucee5-sbx.trycf.com/lucee5/getremote.cfm' \
  -H 'authority: lucee5-sbx.trycf.com' \
  -H 'accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3;q=0.9' \
  -H 'accept-language: en-GB,en-US;q=0.9,en;q=0.8' \
  -H 'cache-control: max-age=0' \
  -H 'content-type: multipart/form-data; boundary=----WebKitFormBoundaryaYm5TBPgCaT5n3TK' \
  -H 'cookie: _ga=GA1.2.771352503.1647902596; _gid=GA1.2.1730098774.1651605323; _gat_gtag_UA_35934323_2=1' \
  -H 'dnt: 1' \
  -H 'origin: https://trycf.com' \
  -H 'referer: https://trycf.com/' \
  -H 'sec-ch-ua: " Not A;Brand";v="99", "Chromium";v="100", "Google Chrome";v="100"' \
  -H 'sec-ch-ua-mobile: ?0' \
  -H 'sec-ch-ua-platform: "Windows"' \
  -H 'sec-fetch-dest: iframe' \
  -H 'sec-fetch-mode: navigate' \
  -H 'sec-fetch-site: same-site' \
  -H 'sec-fetch-user: ?1' \
  -H 'upgrade-insecure-requests: 1' \
  -H 'user-agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/100.0.4896.127 Safari/537.36' \
  --data-raw $'------WebKitFormBoundaryaYm5TBPgCaT5n3TK\r\nContent-Disposition: form-data; name="setupcode"\r\n\r\n\r\n------WebKitFormBoundaryaYm5TBPgCaT5n3TK\r\nContent-Disposition: form-data; name="zoom"\r\n\r\n\r\n------WebKitFormBoundaryaYm5TBPgCaT5n3TK\r\nContent-Disposition: form-data; name="code"\r\n\r\n<cfscript>\r\nwriteOutput("hi")\r\n\r\n</cfscript>\r\n------WebKitFormBoundaryaYm5TBPgCaT5n3TK\r\nContent-Disposition: form-data; name="postcode"\r\n\r\n\r\n------WebKitFormBoundaryaYm5TBPgCaT5n3TK\r\nContent-Disposition: form-data; name="key"\r\n\r\nmain1651930152982-9b67997d-643d-3ddf-0b9f-6154282cfcf4\r\n------WebKitFormBoundaryaYm5TBPgCaT5n3TK\r\nContent-Disposition: form-data; name="asserts"\r\n\r\n\r\n------WebKitFormBoundaryaYm5TBPgCaT5n3TK--\r\n' \
  --compressed

I can run that in bash and it works fine. BTW, the actual code I'm running is buried in the middle there, There's quite a chunk of overhead to execute that code, and I reckoned the browser was probably being a bit belt-n-braces about all the headers it was sending, and I'd not need most of them. I whittled it down to this:

curl 'https://lucee5-sbx.trycf.com/lucee5/getremote.cfm' \
  -H 'content-type: multipart/form-data; boundary=----__trycf__' \
  --data-raw $'------__trycf__\r\nContent-Disposition: form-data; name="setupcode"\r\n\r\n\r\n------__trycf__\r\nContent-Disposition: form-data; name="code"\r\n\r\n<cfscript>\r\nwriteOutput("hi")\r\n</cfscript>\r\n------__trycf__\r\nContent-Disposition: form-data; name="asserts"\r\n\r\n\r\n------__trycf__--\r\n' \
  --compressed

There's a handy site that converts curls to language-specific implementations, and CFML is one of the options: https://curlconverter.com/#cfml. This was handy in theory, but the HTTP service call it created didn't work. Not its fault: it should have, but it seems CFHTTP can't handle that boundary syntax in the curl. Note that PHP's version also struggled, but the JS (fetch), Java and Python versions all worked fine.

This threw me for a while cos I'm not really that au fait with building HTTP requests by hand, but eventually I cracked it. Don't hand-crank the multipart boundary stuff: let CFML do it for you. So I came up with this proof of concept:

<cfset code = fileRead(expandPath("./code.cfm"))>

<cfhttp method="post" url="https://acf14-sbx.trycf.com/getremote.cfm" result="httpResponse">
    <cfhttpparam type="formField" name="code" value=#code#>
    <cfhttpparam type="formField" name="asserts" value="">
</cfhttp>

<cfif httpResponse.statusCode EQ "200 OK">
    <cfoutput>#httpResponse.fileContent#</cfoutput>
<cfelse>
    <cfdump var="#httpResponse#">
</cfif>

That's pretty simple. And my test code for this is just:

<cfscript>
    name = "Scott Steinbeck"
    writeOutput("G'day #name#")
</cfscript>

Results:

G'day Scott Steinbeck

(It was Scott that asked me to write this up).

That's where I've got to so far. I also want to see how I can include some set-up code. Hang on a sec whilst I watch some more HTTP traffic.

[…]

Oh OK, that was easy:

<cfset framework = fileRead(expandPath("./tinyTestFramework.cfm"))>
<cfset tests = fileRead(expandPath("./tests.cfm"))>

<cfhttp method="post" url="https://acf14-sbx.trycf.com/getremote.cfm" result="httpResponse">
    <cfhttpparam type="formField" name="setupcode" value="#framework#">
    <cfhttpparam type="formField" name="code" value="#tests#">
    <cfhttpparam type="formField" name="asserts" value="">
</cfhttp>

<cfif httpResponse.statusCode EQ "200 OK">
    <cfoutput>#httpResponse.fileContent#</cfoutput>
<cfelse>
    <cfdump var="#httpResponse#">
</cfif>

(code on github)

That example just runs the test for my test framework up on trycf instead of here on my own server. Because I can. At least now I remember why I wanted to do this in the first place, but that will be in a later article.

All these test so far only run on ColdFusion 2021, because that was what I was wanting to do. The other hosts are easy enough to glean just by watching the request when clicking "run code". The Lucee (latest) one is https://lucee5-sbx.trycf.com/lucee5/getremote.cfm

Anyway, not a terribly exciting one this (not like how terribly exciting the shit I write here usually is, eh? EH??), but problem solved and hopefully this will help Scott.

Righto.

--
Adam