1 files changed, 79 insertions, 0 deletions
diff --git a/layout/reftests/font-matching/descriptor-ranges.js b/layout/reftests/font-matching/descriptor-ranges.js
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+++ b/layout/reftests/font-matching/descriptor-ranges.js
@@ -0,0 +1,79 @@
+/* Script used by descriptor-ranges.html and descriptor-ranges-ref.html
+   to create @font-face rules and test elements for a collection of
+   font-matching testcases. */
+
+// To create unique font-family names for each testcase.
+let serial = 0;
+
+// Accumulators for the lists of @font-face rules and test elements.
+let fontFaceRules = "";
+let testElements = "";
+
+// Create a <div> element with the font properties to match. Its text reports
+// the property-value and corresponding pair of descriptors being tested.
+// (The associated createFontFaceRules() function is defined separately in the
+// test and reference files.)
+function createTestElement(family, weight, style, stretch, value, expected, unexpected) {
+    return `<div style="font-family:${family}; font-weight:${weight}; font-style:${style}; font-stretch:${stretch};">` +
+           `${family} ${value} (${expected} vs ${unexpected})</div>\n`;
+}
+
+// Create testcases for the given descriptor.
+// Each testcase has a test property value, and a list of @font-face descriptors
+// to be matched against the property, where each descriptor in the list should
+// be preferred over the next.
+function testDescriptor(descriptorName, testCases) {
+    testElements += `<div style="background:yellow;padding:0.5em">Tests of ${descriptorName} descriptor:</div>\n`;
+    testCases.forEach(function (testCase) {
+        // Go though test cases, checking each descriptor has higher priority than next in the list
+        for (let i = 0; i < testCase.testDescriptors.length - 1; i++) {
+            serial++;
+            let expectedMatch   = testCase.testDescriptors[i];
+            let unexpectedMatch = testCase.testDescriptors[i + 1];
+            let familyName = "test_" + serial;
+            fontFaceRules += createFontFaceRules(familyName, descriptorName, expectedMatch, unexpectedMatch);
+            let testWeight  = (descriptorName == "font-weight")  ? testCase.value : "normal";
+            let testStyle   = (descriptorName == "font-style")   ? testCase.value : "normal";
+            let testStretch = (descriptorName == "font-stretch") ? testCase.value : "normal";
+            testElements += createTestElement(familyName, testWeight, testStyle, testStretch,
+                                              testCase.value, expectedMatch, unexpectedMatch);
+        }
+    });
+}
+
+// Testcases (from web-platform/tests/css/css-fonts/variations/at-font-face-font-matching.html,
+// with a couple of extras). In each case, for the given property value, the testDescriptors
+// are listed from 'best' to 'worse' match, as evaluated by the font-matching algorithm in
+// https://drafts.csswg.org/css-fonts-4/#font-style-matching.
+testDescriptor("font-weight", [
+    { value: "400", testDescriptors: ["400", "450 460", "500", "350 399", "351 398", "501 550", "502 560"] },
+    { value: "430", testDescriptors: ["420 440", "450 460", "500", "400 425", "350 399", "340 398", "501 550", "502 560"] },
+    { value: "500", testDescriptors: ["500", "450 460", "400", "350 399", "351 398", "501 550", "502 560"] },
+    { value: "501", testDescriptors: ["501", "502 510", "503 520", "500", "450 460", "390 410", "300 350"] },
+    { value: "399", testDescriptors: ["350 399", "340 360", "200 300", "400", "450 460", "500 501", "502 510"] },
+    { value: "350", testDescriptors: ["200 300", "250 280", "420 450", "430 440", "445"] },
+    { value: "550", testDescriptors: ["600 800", "700 900", "420 450", "430 440", "425"] }
+]);
+
+testDescriptor("font-stretch", [
+    { value: "100%", testDescriptors: ["100%", "110% 120%", "115% 116%"] },
+    { value: "110%", testDescriptors: ["110% 120%", "115% 116%", "105%", "100%", "50% 80%", "60% 70%"] },
+    { value: "90%",  testDescriptors: ["90% 100%", "50% 80%", "60% 70%", "110% 140%", "120% 130%"] },
+]);
+
+testDescriptor("font-style", [
+    { value: "normal",         testDescriptors: ["normal", "oblique 0deg", "oblique 10deg 40deg", "oblique 20deg 30deg", "oblique -50deg -20deg", "oblique -40deg -30deg" ] },
+    { value: "italic",         testDescriptors: ["italic", "oblique 20deg", "oblique 30deg 60deg", "oblique 40deg 50deg", "oblique 5deg 10deg", "oblique 5deg", "normal", "oblique 0deg", "oblique -60deg -30deg", "oblique -50deg -40deg" ] },
+    { value: "oblique 20deg",  testDescriptors: ["oblique 20deg", "oblique 30deg 60deg", "oblique 40deg 50deg", "oblique 10deg", "italic", "oblique 0deg", "oblique -50deg -20deg", "oblique -40deg -30deg" ] },
+    { value: "oblique 21deg",  testDescriptors: ["oblique 21deg", "oblique 30deg 60deg", "oblique 40deg 50deg", "oblique 20deg", "oblique 10deg", "italic", "oblique 0deg",  "oblique -50deg -20deg", "oblique -40deg -30deg" ] },
+    { value: "oblique 10deg",  testDescriptors: ["oblique 10deg", "oblique 5deg", "oblique 15deg 20deg", "oblique 30deg 60deg", "oblique 40deg 50deg", "italic", "oblique 0deg", "oblique -50deg -20deg", "oblique -40deg -30deg" ] },
+    { value: "oblique 0deg",   testDescriptors: ["oblique 0deg", "oblique 5deg", "oblique 15deg 20deg", "oblique 30deg 60deg", "oblique 40deg 50deg", "italic", "oblique -50deg -20deg", "oblique -40deg -30deg" ] },
+    { value: "oblique -10deg", testDescriptors: ["oblique -10deg", "oblique -5deg", "oblique -1deg 0deg", "oblique -20deg -15deg", "oblique -60deg -30deg", "oblique -50deg -40deg", "italic", "oblique 0deg 10deg", "oblique 40deg 50deg" ] },
+    { value: "oblique -20deg", testDescriptors: ["oblique -20deg", "oblique -60deg -40deg", "oblique -10deg", "italic", "oblique 0deg", "oblique 30deg 60deg", "oblique 40deg 50deg"] },
+    { value: "oblique -21deg", testDescriptors: ["oblique -21deg", "oblique -60deg -40deg", "oblique -10deg", "italic", "oblique 0deg", "oblique 30deg 60deg", "oblique 40deg 50deg"] },
+]);
+
+// Stuff the @font-face rules and test elements into the document.
+// Any testcases that render Ahem glyphs are failures.
+document.getElementById("dynamicStyles").innerHTML = fontFaceRules;
+document.getElementById("testContents").innerHTML = testElements;