Made LengthStyleInterpolationTest display better output when failing

Made LengthStyleInterpolationTest display better output when failing

LengthStyleInterpolationTest currently uses functions to test for pass
and fail conditions. Updated it to use macros that call gtests' EXPECT
macros instead, to give more helpful output on test failure.

Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=197517

[sashab, 2015-06-20 01:03:47]

sashab@chromium.org changed reviewers:
+ esprehn@chromium.org

[sashab, 2015-06-20 01:03:47]

Super quick review; just something that would help me debug the failing windows
bot in https://codereview.chromium.org/1164573002/

[esprehn, 2015-06-20 01:07:32]

https://codereview.chromium.org/1193053002/diff/1/Source/core/animation/Lengt...
File Source/core/animation/LengthStyleInterpolationTest.cpp (right):

https://codereview.chromium.org/1193053002/diff/1/Source/core/animation/Lengt...
Source/core/animation/LengthStyleInterpolationTest.cpp:67: #define
TEST_PRIMITIVE_VALUE(ACTUAL_VALUE, EXPECTED_DOUBLE_VALUE, EXPECTED_UNIT_TYPE)   
            \
Why can't this be a regular function?

https://codereview.chromium.org/1193053002/diff/1/Source/core/animation/Lengt...
Source/core/animation/LengthStyleInterpolationTest.cpp:72: #define
EXPECT_CSS_LENGTH_ARRAY_ELEMENTS_EQUAL(EXPECTED, ACTUAL)        \
just make a function?

[esprehn, 2015-06-20 01:18:41]

lgtm

https://codereview.chromium.org/1193053002/diff/1/Source/core/animation/Lengt...
File Source/core/animation/LengthStyleInterpolationTest.cpp (right):

https://codereview.chromium.org/1193053002/diff/1/Source/core/animation/Lengt...
Source/core/animation/LengthStyleInterpolationTest.cpp:67: #define
TEST_PRIMITIVE_VALUE(ACTUAL_VALUE, EXPECTED_DOUBLE_VALUE, EXPECTED_UNIT_TYPE)   
            \
I think we normally name these with regular variable names.

actualValue, expectedDoubleValue etc.

[sashab, 2015-06-20 01:20:08]

I'm reading through gtests documentation now to see if there's a way to get a
stack trace from a failed EXPECT. But I have a feeling there isn't -- I've seen
this macro pattern before.

https://codereview.chromium.org/1193053002/diff/1/Source/core/animation/Lengt...
File Source/core/animation/LengthStyleInterpolationTest.cpp (right):

https://codereview.chromium.org/1193053002/diff/1/Source/core/animation/Lengt...
Source/core/animation/LengthStyleInterpolationTest.cpp:67: #define
TEST_PRIMITIVE_VALUE(ACTUAL_VALUE, EXPECTED_DOUBLE_VALUE, EXPECTED_UNIT_TYPE)   
            \
On 2015/06/20 01:07:31, esprehn wrote:
> Why can't this be a regular function?

If these fail inside a regular function, the line with the failing EXPEC'
statement will be ambiguous since it doesn't reference the line number of it's
calling function.

E.g. in the old code, a failed test would result in a message like
e:...lengthstyleinterpolationtest.cpp(34): error, so even if you knew the
failing test was ZeroLength you wouldn't know which value was incorrect (value1,
value2 or value3). With the macro, the line number specified is the actual line
of the macro (e.g. line 86 or 89).

Strictly speaking, it's *still* ambiguous, since if TEST_PRIMITIVE_VALUE fails
you don't know which of the 3 EXPECT statements is actually the failing one.
However, gtest outputs the string value of part of the EXPECT statement so you
can figure out which one it is (e.g. error: Value of: (actual).at(i) for the
test below).

https://codereview.chromium.org/1193053002/diff/1/Source/core/animation/Lengt...
Source/core/animation/LengthStyleInterpolationTest.cpp:72: #define
EXPECT_CSS_LENGTH_ARRAY_ELEMENTS_EQUAL(EXPECTED, ACTUAL)        \
On 2015/06/20 01:07:31, esprehn wrote:
> just make a function?

Same as above. As far as I know gtest never gives a stack trace for broken
EXPECT statements.

[sashab, 2015-06-20 01:32:34]

The CQ bit was checked by sashab@chromium.org

[commit-bot: I haz the power, 2015-06-20 01:32:52]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1193053002/1

[commit-bot: I haz the power, 2015-06-20 01:36:47]

Committed patchset #1 (id:1) as
https://src.chromium.org/viewvc/blink?view=rev&revision=197517