Bug 203226 – Add a script to run ImageDiff manually

• Component: Tools / Tests
• Status: RESOLVED FIXED

[Carlos Alberto Lopez Perez]

While trying to debug a possible issue with ImageDiff I found that is really hard to run this test manually (without using the layout-test runner).

The main issue is that the tool doesn't accept the paths to the images. Instead it expects via stdin the contents of both images (as byte strings), with some fields that tell it how much bytes each image uses on stdin.

[Carlos Alberto Lopez Perez]

Created attachment 381489 [details]
Patch

[Carlos Alberto Lopez Perez]

Created attachment 381494 [details]
Patch

[Adrian Perez]

Comment on attachment 381494 [details]
Patch

The new Python script looks fine. I think that the failed test case of
the “webkitperl” EWS is somewhat intermittent (for example here's another
recent failure: https://ews-build.webkit.org/#/builders/19/builds/11760),
and it should be fine to land this.

[Carlos Alberto Lopez Perez]

Comment on attachment 381494 [details]
Patch

Clearing flags on attachment: 381494

Committed r251428: <https://trac.webkit.org/changeset/251428>

[Carlos Alberto Lopez Perez]

All reviewed patches have been landed.  Closing bug.

[Radar WebKit Bug Importer]

<rdar://problem/56496270>

[Nikolas Zimmermann]

```
nzimmermann@nzimmermann-macbook WebKit % run-imagediff  LayoutTests/svg/foreignObject/body-background-expected.png actual.png    
Traceback (most recent call last):
  File "/Users/nzimmermann/Software/GitRepositories/WebKit/Tools/Scripts/run-imagediff", line 70, in <module>
    image_diff, diff_percent, error = port.diff_image(imageContentA, imageContentB, options.tolerance)
TypeError: cannot unpack non-iterable ImageDiffResult object
```

The script is outdated. Shall we update it? Carlos?