Just a Theory

By David E. Wheeler

New JavaScript Testing Method: TestSimple

I’m pleased to announce the first alpha release of my port of Test::Simple/Test::More/Test::Builder to JavaScript. Download it now and let me know what you think!

You can see what the tests look like by loading the files in the tests/ directory into your Web browser. This is my first stab at what I hope becomes a complete port. I could use some feedback/ideas on a number of outstanding issues:

  • I have made no decisions as to where to output test results, diagnostics, etc. Currently, they’re simply output to document.write(). This may well be the best place in the long run, though it might be nice to allow users to configure where output goes. It will also be easy to control the output, since the output functions can easily be replaced in JavaScript. Suggestions welcome.
  • I have no idea how to exit execution of tests other than by throwing an exception, which is only supported by JavaScript 1.5, anyway, AFAIK. As a result, skipAll(), BAILOUT(), and skipRest() do not work.
  • Skip and Todo tests currently don’t work because named blocks (e.g., SKIP: and TODO:) are lexical in JavaScript. Therefore I cannot get at them from within a function called from within a block (at least not that I can tell). It might be that I need to just pass function references to skip() and todo(), instead. This is a rather different interface than that supported by Test::More, but it might work. Thoughts?
  • Currently, one must call Test._ending() to finish running tests. This is because there is no END block to grab on to in JavaScript. Suggestions for how to capture output and append the output of _ending() are welcome. It might work to have the onload event execute it, but then it will have to look for the proper context in which to append it (a <pre> tag, at this point).
  • Anyone have any idea how to get at the line number and file name in a JavaScript? Failures currently aren’t too descriptive. As a result, I’m not sure if level() will have any part to play.
  • Is there threading in JavaScript?
  • I haven’t written TestHarness yet. It may not make sense to even have such a thing in JavaScript; I’m not sure.
  • I’m using a Module::Build script to build a distribution. I don’t think there’s a standard for distributing JavaScript libraries, but I think that this works reasonably well. I have all of the documentation in POD, and the script generates HTML and text versions before creating the tarball. The Build.PL script of course is not included in the distribution. I started out trying to write the documentation in JSDoc, but abandoned it for all of the reasons I recounted last week.
  • Is there a way to dynamically load a JavaScript file? I’d like to use an approach to have TestMore.js and TestSimple.js load TestBuilder.js. I’d also like to use it to implement loadOk() (equivalent to Test::More’s use_ok() and require_ok() subroutines).

More details are in the ToDo section of the TestBuilder docs.

Let me know what you think!

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