A thread safe CSS calc parser for sizes

Source/core/css/parser/SizesCalcParserTest.cpp

+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "config.h"
+#include "core/css/parser/SizesCalcParser.h"
+
+#include "core/css/MediaValuesCached.h"
+#include "core/css/parser/MediaQueryTokenizer.h"
+
+#include <gtest/gtest.h>
+
+namespace WebCore {
+
+typedef struct {
+    const char* input;
+    const unsigned output;
+    const bool valid;
+} TestCase;

[alancutter (OOO until 2018), 2014/04/30 04:02:17]

struct TestCase {}; notation would be preferred.

+
+TEST(SizesCalcParserTest, Basic)
+{
+    // The first string represents the input string.
+    // The second string represents the output string, if present.
+    // Otherwise, the output string is identical to the first string.

[alancutter (OOO until 2018), 2014/04/30 04:02:17]

This comment doesn't seem to match the struct. The second value appears to be
the resolved value of the calc instead of a string. The "Otherwise" case doesn't
really make sense.

+    TestCase testCases[] = {
+        {"calc(500px + 10em)", 660, true},
+        {"calc(500px + 2 * 10em)", 820, true},
+        {"calc(500px + 2*10em)", 820, true},
+        {"calc(500px + 0.5*10em)", 580, true},
+        {"calc(500px + (0.5*10em + 13px))", 593, true},
+        {"calc(100vw + (0.5*10em + 13px))", 593, true},
+        {"calc(100vh + (0.5*10em + 13px))", 736, true},
+        {"calc(100vh + calc(0.5*10em + 13px))", 736, true},
+        {"calc(100vh + (50%*10em + 13px))", 0, false},
+        {"calc(50em+13px)", 0, false},
+        {"calc(50em-13px)", 0, false},
+        {"calc(500px + 10)", 0, false},
+        {"calc(500 + 10)", 0, false},
+        {"calc(500px + 10s)", 0, false},
+        {"calc(500px + 1cm)", 537, true},
+        {"calc(500px - 10s)", 0, false},
+        {"calc(500px - 1cm)", 463, true},
+        {"calc(50px*10)", 500, true},
+        {"calc(50px*10px)", 0, false},
+        {"calc(50px/10px)", 0, false},
+        {"calc(500px/10)", 50, true},
+        {"calc(500/10)", 0, false},
+        {"calc(500px/0.5)", 1000, true},
+        {"calc(500px/.5)", 1000, true},
+        {"calc(500/0)", 0, false},
+        {"calc(500px/0)", 0, false},
+        {"calc(-500px/10)", 0, true},
+        {0, 0, true} // Do not remove the terminator line.

[alancutter (OOO until 2018), 2014/04/30 04:02:17]

It would be good to see more invalid inputs tested.
See the "invalid formulas" section in css3/calc/calc-errors.html

And perhaps these cases as well:
calc(((4) * ((10px))))
calc(50px / 0)
calc(50px / (10 + 10))
calc(50px / (10 - 10))
calc(50px / (10 * 10))
calc(50px / (10 / 10))

+    };
+
+
+    MediaValuesCached::MediaValuesCachedData data;
+    data.viewportWidth = 500;
+    data.viewportHeight = 643;
+    data.deviceWidth = 500;
+    data.deviceHeight = 643;
+    data.devicePixelRatio = 2.0;
+    data.colorBitsPerComponent = 24;
+    data.monochromeBitsPerComponent = 0;
+    data.pointer = MediaValues::MousePointer;
+    data.defaultFontSize = 16;
+    data.threeDEnabled = true;
+    data.scanMediaType = false;
+    data.screenMediaType = true;
+    data.printMediaType = false;
+    data.strictMode = true;
+    RefPtr<MediaValues> mediaValues = MediaValuesCached::create(data);
+
+    for (unsigned i = 0; testCases[i].input; ++i) {
+        Vector<MediaQueryToken> tokens;
+        MediaQueryTokenizer::tokenize(testCases[i].input, tokens);
+        unsigned output;
+        bool valid = SizesCalcParser::parse(tokens.begin(), tokens.end(), mediaValues, output);
+        ASSERT_EQ(testCases[i].valid, valid);
+        if (valid)
+            ASSERT_EQ(testCases[i].output, output);
+    }
+}
+
+} // namespace