TDOP Experiment

Inspired by Douglas Crockford's talk at the goto; conference about top down operator precence, a PHP version of the code explained here.

Code

The following is our simplemost unittest runner written in TOP, the programming language I created with a TDOP parser.

var test = new Type(args[0]);

print 'Running tests in ' ~ test.name ~ ':';

foreach (method : test.methods()) {
  if (method.annotationPresent('test')) {
    try {
      method.invoke(test.newInstance());
      print '✓ OK ' ~ method.name;
    } catch (e) {
      print '✗ FAIL ' ~ method.name ~ ': ' ~ e.toString();
    }
  }
}

return 0;

The class under test is the following:

class Person {
  handle, name;

  def this(handle, name) {
    this.handle = handle ?? null;
    this.name = name ?? null;
  }

  def toString() {
    return 'Person<@' ~ this.handle ~ '>';
  }
}

The unittest is written as follows:

class PersonTest : Test {
  handle = 'Test', name = 'Unit Tester';

  // ... shortened for brevity ...

  @test def name_accessor() {
    this.assertEquals(this.name, new Person(this.handle, this.name).name);
  }

  @test def string_representation() {
    this.assertEquals('Person<@Test>', new Person(this.handle).toString());
  }
}

Running it can be done by invoking the following:

$ xp text.parse.tdop.Vm examples/run-test.top PersonTest
>> 0.001 seconds to compile file examples/run-test.top
Running tests in PersonTest:
✓ OK can_create
✓ OK create_with_handle
✓ OK create_with_handle_and_name
✓ OK handle_accessor
✓ OK name_accessor
✓ OK string_representation
>> 0.004 seconds to execute script, result= 0