https://darobin.github.io/test-harness-tutorial/docs/using-testharness.html

According to this documentation (not sure about its current status), testharness has the following assertion primitives:

assert_true
assert_false
assert_equals
assert_not_equals
assert_in_array
assert_array_equals
assert_approx_equals
assert_regexp_match
assert_own_property
assert_inherits
assert_readonly
assert_throws
assert_unreached

Why own_property, inherits, readonly deserve its place in Audit? I think it should be all or nothing. By minimizing the surface of testharness in Audit, we will have a better independency. If you think their primitives are better, we should adapt Audit - but then it will cause another set of issues: we have to update Audit and expected files every time testharness updates theirs.

Using true/false assertion only seems to be the most efficient (and future-proof) from my perspective. If you think we need more granularity in assertion types, I can certainly add our own.

We have equivalents for true, false, equals, not_equals, in_array (sort of?), array_equals, approx_equals, and throws.

I don't expect we need regexp_match or unreached.  That leaves just own_property, inherits, readonly.  These are just convenience functions so I don't have to remember how to test own_property, inherits, and readonly.

Okay then. I will add our own version of assertions for own_property, inherits, and readonly.

rtoy@

Do you have any test that can use these new feature? I can include those changes in the CL.

rtoy@ I am looking at how these assertions are implemented in testharness:

* readonly: This literally tries to overwrite the data and see if the value is changed. The comment on
  the code also warns about the side effect of this check. I rather not have this in Audit.

* own_property:
  should('propertyName').beOwnPropertyOf(Object);

* inherits: I think we are more interested in the relationship between class. So I think we want to have:
  should(ChildObject).beInheritedFrom(ParentClassName);

audio-scheduled-source-basic.html uses hasOwnProperty.

Not having readonly is not a big deal, especially given how it's currently implemented in testharness.

The other ideas look fine.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/b7faac578f403d2a6bb4a767578661079cbf5963

commit b7faac578f403d2a6bb4a767578661079cbf5963
Author: hongchan <hongchan@chromium.org>
Date: Fri Apr 07 19:48:02 2017

Implement ownProperty() and inheritFrom() assertions in should()

This CL add two assertions that abstracts the checks for JavaScript
traits.

 - should().ownProperty()
 - should().inheritFrom()

BUG= 702708 
TEST=webaudio/unit-tests/audit.html

Review-Url: https://codereview.chromium.org/2805773002
Cr-Commit-Position: refs/heads/master@{#462970}

[modify] https://crrev.com/b7faac578f403d2a6bb4a767578661079cbf5963/third_party/WebKit/LayoutTests/webaudio/audio-scheduled-source-basic.html
[modify] https://crrev.com/b7faac578f403d2a6bb4a767578661079cbf5963/third_party/WebKit/LayoutTests/webaudio/resources/audit.js
[modify] https://crrev.com/b7faac578f403d2a6bb4a767578661079cbf5963/third_party/WebKit/LayoutTests/webaudio/unit-tests/audit-expected.txt
[modify] https://crrev.com/b7faac578f403d2a6bb4a767578661079cbf5963/third_party/WebKit/LayoutTests/webaudio/unit-tests/audit.html