hmtl_diff: Show only three lines before/after a diff block.

hmtl_diff: Show only three lines before/after a diff block.

Introduces HtmlDiffGenerator class to hold line numbers.

BUG=691883
Review-Url: https://codereview.chromium.org/2695993002
Cr-Commit-Position: refs/heads/master@{#450588}
Committed: https://chromium.googlesource.com/chromium/src/+/0e0444a4895f138db12a1722679d8a6be17fad11

[tkent, 2017-02-14 16:56:23]

The CQ bit was checked by tkent@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2017-02-14 16:56:44]

Dry run: CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[tkent, 2017-02-14 16:57:30]

tkent@chromium.org changed reviewers:
+ qyearsley@chromium.org

[tkent, 2017-02-14 16:57:30]

qyearsley@, would you review this please?

[commit-bot: I haz the power, 2017-02-14 17:52:49]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2017-02-14 17:52:50]

Dry run: This issue passed the CQ dry run.

[qyearsley, 2017-02-15 00:02:22]

Thanks, this is definitely an improvement! Left a few comments for optional
possible changes.

(Note, html_diff is used now for diffs in results.html, but not for webkit-patch
pretty-diff, so this won't affect webkit-patch pretty-diff, which still uses
PrettyPatch.rb. In order to replace webkit-patch pretty-diff, I still think
we'll (I'll?) want to add something which takes git patches as input (which can
include diffs of multiple files) and produces HTML as output.

https://codereview.chromium.org/2695993002/diff/1/third_party/WebKit/Tools/Sc...
File third_party/WebKit/Tools/Scripts/webkitpy/common/html_diff.py (right):

https://codereview.chromium.org/2695993002/diff/1/third_party/WebKit/Tools/Sc...
third_party/WebKit/Tools/Scripts/webkitpy/common/html_diff.py:86: return output
Possible refactoring: Could lines 66 to 86 here be extracted to a _format_equal
method, and _format_equal could be renamed _format_equal_line?

https://codereview.chromium.org/2695993002/diff/1/third_party/WebKit/Tools/Sc...
File third_party/WebKit/Tools/Scripts/webkitpy/common/html_diff_unittest.py
(right):

https://codereview.chromium.org/2695993002/diff/1/third_party/WebKit/Tools/Sc...
third_party/WebKit/Tools/Scripts/webkitpy/common/html_diff_unittest.py:37:
html_diff_body(['one line\n'], ['one line\n']),
Rather than continuing to use html_diff_body, you could also directly use
HtmlDiffGenerator().generate_tbody(...) or html_diff() in these test methods.

Advantages: More closely reflects how the code under test could actually be
used.
Disadvantages: A bit more verbose.

[qyearsley, 2017-02-15 00:02:45]

On 2017/02/15 at 00:02:22, qyearsley wrote:
> Thanks, this is definitely an improvement! Left a few comments for optional
possible changes.
> 
> (Note, html_diff is used now for diffs in results.html, but not for
webkit-patch pretty-diff, so this won't affect webkit-patch pretty-diff, which
still uses PrettyPatch.rb. In order to replace webkit-patch pretty-diff, I still
think we'll (I'll?) want to add something which takes git patches as input
(which can include diffs of multiple files) and produces HTML as output.
> 
>
https://codereview.chromium.org/2695993002/diff/1/third_party/WebKit/Tools/Sc...
> File third_party/WebKit/Tools/Scripts/webkitpy/common/html_diff.py (right):
> 
>
https://codereview.chromium.org/2695993002/diff/1/third_party/WebKit/Tools/Sc...
> third_party/WebKit/Tools/Scripts/webkitpy/common/html_diff.py:86: return
output
> Possible refactoring: Could lines 66 to 86 here be extracted to a
_format_equal method, and _format_equal could be renamed _format_equal_line?
> 
>
https://codereview.chromium.org/2695993002/diff/1/third_party/WebKit/Tools/Sc...
> File third_party/WebKit/Tools/Scripts/webkitpy/common/html_diff_unittest.py
(right):
> 
>
https://codereview.chromium.org/2695993002/diff/1/third_party/WebKit/Tools/Sc...
> third_party/WebKit/Tools/Scripts/webkitpy/common/html_diff_unittest.py:37:
html_diff_body(['one line\n'], ['one line\n']),
> Rather than continuing to use html_diff_body, you could also directly use
HtmlDiffGenerator().generate_tbody(...) or html_diff() in these test methods.
> 
> Advantages: More closely reflects how the code under test could actually be
used.
> Disadvantages: A bit more verbose.

(LGTM with nits)

[tkent, 2017-02-15 05:02:53]

The CQ bit was checked by tkent@chromium.org

[tkent, 2017-02-15 05:02:54]

The patchset sent to the CQ was uploaded after l-g-t-m from
qyearsley@chromium.org
Link to the patchset: https://codereview.chromium.org/2695993002/#ps20001
(title: "apply review comments")

[commit-bot: I haz the power, 2017-02-15 05:04:05]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[tkent, 2017-02-15 05:08:09]

> (Note, html_diff is used now for diffs in results.html, but not for
webkit-patch pretty-diff, so this won't affect webkit-patch pretty-diff, which
still uses PrettyPatch.rb. In order to replace webkit-patch pretty-diff, I still
think we'll (I'll?) want to add something which takes git patches as input
(which can include diffs of multiple files) and produces HTML as output.

Prettifying |diff| output is an option, of course.  At this moment, improving
the current html_diff.py is easier for me to solve crbug.com/691883.

One advantage of difflib is flexibility.  We might able to add an interactive UI
to show snipped context lines like Rietveld does.

https://codereview.chromium.org/2695993002/diff/1/third_party/WebKit/Tools/Sc...
File third_party/WebKit/Tools/Scripts/webkitpy/common/html_diff.py (right):

https://codereview.chromium.org/2695993002/diff/1/third_party/WebKit/Tools/Sc...
third_party/WebKit/Tools/Scripts/webkitpy/common/html_diff.py:86: return output
On 2017/02/15 at 00:02:22, qyearsley wrote:
> Possible refactoring: Could lines 66 to 86 here be extracted to a
_format_equal method, and _format_equal could be renamed _format_equal_line?

Done.

https://codereview.chromium.org/2695993002/diff/1/third_party/WebKit/Tools/Sc...
File third_party/WebKit/Tools/Scripts/webkitpy/common/html_diff_unittest.py
(right):

https://codereview.chromium.org/2695993002/diff/1/third_party/WebKit/Tools/Sc...
third_party/WebKit/Tools/Scripts/webkitpy/common/html_diff_unittest.py:37:
html_diff_body(['one line\n'], ['one line\n']),
On 2017/02/15 at 00:02:22, qyearsley wrote:
> Rather than continuing to use html_diff_body, you could also directly use
HtmlDiffGenerator().generate_tbody(...) or html_diff() in these test methods.
> 
> Advantages: More closely reflects how the code under test could actually be
used.
> Disadvantages: A bit more verbose.

Done.

[commit-bot: I haz the power, 2017-02-15 06:19:55]

CQ is committing da patch.

Bot data: {"patchset_id": 20001, "attempt_start_ts": 1487134973858830,
"parent_rev": "67362b5be791794950cbfb2b2e5ecb3574ba2e9d", "commit_rev":
"0e0444a4895f138db12a1722679d8a6be17fad11"}

[commit-bot: I haz the power, 2017-02-15 06:21:08]

Description was changed from

==========
hmtl_diff: Show only three lines before/after a diff block.

Introduces HtmlDiffGenerator class to hold line numbers.

BUG=691883
==========

to

==========
hmtl_diff: Show only three lines before/after a diff block.

Introduces HtmlDiffGenerator class to hold line numbers.

BUG=691883

Review-Url: https://codereview.chromium.org/2695993002
Cr-Commit-Position: refs/heads/master@{#450588}
Committed:
https://chromium.googlesource.com/chromium/src/+/0e0444a4895f138db12a1722679d...
==========

[commit-bot: I haz the power, 2017-02-15 06:21:09]

Committed patchset #2 (id:20001) as
https://chromium.googlesource.com/chromium/src/+/0e0444a4895f138db12a1722679d...