Make fast/canvas/canvas-strokePath-shadow.html allow for pixel tolerance

https://bugs.webkit.org/show_bug.cgi?id=79488

Patch by Elliot Poger <epoger@google.com> on 2012-02-24
Reviewed by Adam Barth.

* fast/canvas/script-tests/canvas-strokePath-shadow.js:
(shouldBeAlmost):
* fast/js/resources/js-test-pre.js:
(shouldBeCloseTo):

Canonical link: https://commits.webkit.org/96609@main
git-svn-id: https://svn.webkit.org/repository/webkit/trunk@108835 268f45cc-cd09-0410-ab3c-d52691b4dbfc

LayoutTests/ChangeLog

@@ -1,3 +1,15 @@
+2012-02-24  Elliot Poger  <epoger@google.com>
+
+        Make fast/canvas/canvas-strokePath-shadow.html allow for pixel tolerance
+        https://bugs.webkit.org/show_bug.cgi?id=79488
+
+        Reviewed by Adam Barth.
+
+        * fast/canvas/script-tests/canvas-strokePath-shadow.js:
+        (shouldBeAlmost):
+        * fast/js/resources/js-test-pre.js:
+        (shouldBeCloseTo):
+
 2012-02-24  Tim Horton  <timothy_horton@apple.com>
 
         SVG should be supported in Dashboard compatibility mode

LayoutTests/fast/canvas/canvas-strokePath-shadow-expected.txt

@@ -3,34 +3,34 @@ Ensure correct behavior of canvas with path stroke shadow
 On success, you will see a series of "PASS" messages, followed by "TEST COMPLETE".
 
 
-PASS data[0] is 255
-PASS data[1] is 20
-PASS data[2] is 0
-PASS data[0] is 255
-PASS data[1] is 20
-PASS data[2] is 0
-PASS data[0] is 255
-PASS data[1] is 20
-PASS data[2] is 0
-PASS data[0] is 255
-PASS data[1] is 20
-PASS data[2] is 0
-PASS data[0] is 255
-PASS data[1] is 0
-PASS data[2] is 0
-PASS data[3] should not be 255 and it's not.
-PASS data[0] is 255
-PASS data[1] is 0
-PASS data[2] is 0
-PASS data[3] should not be 255 and it's not.
-PASS data[0] is 255
-PASS data[1] is 0
-PASS data[2] is 0
-PASS data[3] should not be 255 and it's not.
-PASS data[0] is 255
-PASS data[1] is 0
-PASS data[2] is 0
-PASS data[3] should not be 255 and it's not.
+PASS data[0] is within 2 of 255
+PASS data[1] is within 2 of 20
+PASS data[2] is within 2 of 0
+PASS data[0] is within 2 of 255
+PASS data[1] is within 2 of 20
+PASS data[2] is within 2 of 0
+PASS data[0] is within 2 of 255
+PASS data[1] is within 2 of 20
+PASS data[2] is within 2 of 0
+PASS data[0] is within 2 of 255
+PASS data[1] is within 2 of 20
+PASS data[2] is within 2 of 0
+PASS data[0] is within 2 of 255
+PASS data[1] is within 2 of 0
+PASS data[2] is within 2 of 0
+PASS data[3] is not 255
+PASS data[0] is within 2 of 255
+PASS data[1] is within 2 of 0
+PASS data[2] is within 2 of 0
+PASS data[3] is not 255
+PASS data[0] is within 2 of 255
+PASS data[1] is within 2 of 0
+PASS data[2] is within 2 of 0
+PASS data[3] is not 255
+PASS data[0] is within 2 of 255
+PASS data[1] is within 2 of 0
+PASS data[2] is within 2 of 0
+PASS data[3] is not 255
 PASS successfullyParsed is true
 
 TEST COMPLETE

LayoutTests/fast/canvas/script-tests/canvas-strokePath-shadow.js

@@ -10,19 +10,10 @@ function print(message, color)
     document.getElementById("console").appendChild(paragraph);
 }
 
-function shouldNotBe(a, b)
+// Level of tolerance we expect of most pixel comparisons in this test.
+function shouldBeAlmost(_a, _b)
 {
-    var evalA;
-    try {
-        evalA = eval(a);
-    } catch(e) {
-        evalA = e;
-    }
-
-    if (evalA != b)
-        print("PASS " + a + " should not be " + b + " and it's not.", "green")
-    else
-        print("FAIL " + a + " should not be " + b + " but it is.", "red");
+    shouldBeCloseTo(_a, _b, 2);
 }
 
 var canvas = document.createElement('canvas');
@@ -62,53 +53,53 @@ var imageData, data;
 // Verify solid shadow.
 imageData = ctx.getImageData(650, 300, 1, 1);
 data = imageData.data;
-shouldBe('data[0]', '255');
-shouldBe('data[1]', '20');
-shouldBe('data[2]', '0');
+shouldBeAlmost('data[0]', 255);
+shouldBeAlmost('data[1]', 20);
+shouldBeAlmost('data[2]', 0);
 
 imageData = ctx.getImageData(650, 50, 1, 1);
 data = imageData.data;
-shouldBe('data[0]', '255');
-shouldBe('data[1]', '20');
-shouldBe('data[2]', '0');
+shouldBeAlmost('data[0]', 255);
+shouldBeAlmost('data[1]', 20);
+shouldBeAlmost('data[2]', 0);
 
 imageData = ctx.getImageData(380, 30, 1, 1);
 data = imageData.data;
-shouldBe('data[0]', '255');
-shouldBe('data[1]', '20');
-shouldBe('data[2]', '0');
+shouldBeAlmost('data[0]', 255);
+shouldBeAlmost('data[1]', 20);
+shouldBeAlmost('data[2]', 0);
 
 imageData = ctx.getImageData(400, 40, 1, 1);
 data = imageData.data;
-shouldBe('data[0]', '255');
-shouldBe('data[1]', '20');
-shouldBe('data[2]', '0');
+shouldBeAlmost('data[0]', 255);
+shouldBeAlmost('data[1]', 20);
+shouldBeAlmost('data[2]', 0);
 
 // Verify blurry shadow.
 imageData = ctx.getImageData(640, 640, 1, 1);
 data = imageData.data;
-shouldBe('data[0]', '255');
-shouldBe('data[1]', '0');
-shouldBe('data[2]', '0');
+shouldBeAlmost('data[0]', 255);
+shouldBeAlmost('data[1]', 0);
+shouldBeAlmost('data[2]', 0);
 shouldNotBe('data[3]', '255');
 
 imageData = ctx.getImageData(650, 400, 1, 1);
 data = imageData.data;
-shouldBe('data[0]', '255');
-shouldBe('data[1]', '0');
-shouldBe('data[2]', '0');
+shouldBeAlmost('data[0]', 255);
+shouldBeAlmost('data[1]', 0);
+shouldBeAlmost('data[2]', 0);
 shouldNotBe('data[3]', '255');
 
 imageData = ctx.getImageData(380, 380, 1, 1);
 data = imageData.data;
-shouldBe('data[0]', '255');
-shouldBe('data[1]', '0');
-shouldBe('data[2]', '0');
+shouldBeAlmost('data[0]', 255);
+shouldBeAlmost('data[1]', 0);
+shouldBeAlmost('data[2]', 0);
 shouldNotBe('data[3]', '255');
 
 imageData = ctx.getImageData(350, 380, 1, 1);
 data = imageData.data;
-shouldBe('data[0]', '255');
-shouldBe('data[1]', '0');
-shouldBe('data[2]', '0');
+shouldBeAlmost('data[0]', 255);
+shouldBeAlmost('data[1]', 0);
+shouldBeAlmost('data[2]', 0);
 shouldNotBe('data[3]', '255');

LayoutTests/fast/js/resources/js-test-pre.js

@@ -187,6 +187,45 @@ function shouldBe(_a, _b, quiet)
     testFailed(_a + " should be " + _bv + " (of type " + typeof _bv + "). Was " + _av + " (of type " + typeof _av + ").");
 }
 
+// Variant of shouldBe()--confirms that result of eval(_to_eval) is within
+// numeric _tolerance of numeric _target.
+function shouldBeCloseTo(_to_eval, _target, _tolerance, quiet)
+{
+  if (typeof _to_eval != "string") {
+    testFailed("shouldBeCloseTo() requires string argument _to_eval. was type " + typeof _to_eval);
+    return;
+  }
+  if (typeof _target != "number") {
+    testFailed("shouldBeCloseTo() requires numeric argument _target. was type " + typeof _target);
+    return;
+  }
+  if (typeof _tolerance != "number") {
+    testFailed("shouldBeCloseTo() requires numeric argument _tolerance. was type " + typeof _tolerance);
+    return;
+  }
+
+  var _result;
+  try {
+     _result = eval(_to_eval);
+  } catch (e) {
+    testFailed(_to_eval + " should be within " + _tolerance + " of "
+               + _target + ". Threw exception " + e);
+    return;
+  }
+
+  if (typeof(_result) != typeof(_target)) {
+    testFailed(_to_eval + " should be of type " + typeof _target
+               + " but was of type " + typeof _result);
+  } else if (Math.abs(_result - _target) <= _tolerance) {
+    if (!quiet) {
+        testPassed(_to_eval + " is within " + _tolerance + " of " + _target);
+    }
+  } else {
+    testFailed(_to_eval + " should be within " + _tolerance + " of " + _target
+               + ". Was " + _result + ".");
+  }
+}
+
 function shouldNotBe(_a, _b, quiet)
 {
   if (typeof _a != "string" || typeof _b != "string")