1 files changed, 196 insertions, 0 deletions
diff --git a/testing/web-platform/tests/css/support/numeric-testcommon.js b/testing/web-platform/tests/css/support/numeric-testcommon.js
new file mode 100644
index 0000000000..3a39e2a973
--- /dev/null
+++ b/testing/web-platform/tests/css/support/numeric-testcommon.js
@@ -0,0 +1,196 @@
+'use strict';
+
+/*
+Provides functions to help test that two numeric values are equivalent.
+These *do not* rely on you predicting what one value will serialize to;
+instead, they set and serialize *both* values,
+and just ensure that they serialize to the same thing.
+
+They rely on a #target element existing in the document,
+as this might rely on layout to resolve styles,
+and so it needs to be in the document.
+
+Three main functions are defined, with the same signatures:
+test_math_used() (for testing used values),
+test_math_computed() (for testing computed values),
+and test_math_specified() (for testing specified values).
+Signature for all is:
+
+test_math_X(
+    testString, // A numeric value; required.
+    expectedString, // A hopefully-equivalent numeric value; required.
+    { // all of these are optional
+        type, // "number", "length", etc. See impl for full list. Defaults to "length".
+        msg, // The message to display for the test; autogenned if not provided.
+        msgExtra, // Extra info to put after the auto-genned message.
+        prop, // If you want to override the automatic choice of tested property.
+        extraStyle, // Styles that need to be set at the same time to properly test the value.
+    }
+);
+
+
+Additionally, five specialized functions are provided
+to test that a given value is ±∞, ±0, or NaN:
+
+* test_plus_infinity(testString)
+* test_minus_infinity(testString)
+* test_plus_zero(testString)
+* test_minus_zero(testString)
+* test_nan(testString)
+
+*/
+
+
+
+function test_math_used(testString, expectedString, {approx, msg, msgExtra, type, prop, prefix, suffix, extraStyle={}}={}) {
+    if(type === undefined) type = "length";
+    if(!prop) {
+        switch(type) {
+            case "number":     prop = "transform"; prefix="scale("; suffix=")"; break;
+            case "integer":    prop = "z-index"; extraStyle.position="absolute"; break;
+            case "length":     prop = "margin-left"; break;
+            case "angle":      prop = "transform"; prefix="rotate("; suffix=")"; break;
+            case "time":       prop = "transition-delay"; break;
+            case "resolution": prop = "image-resolution"; break;
+            case "flex":       prop = "grid-template-rows"; break;
+            default: throw Exception(`Value type '${type}' isn't capable of math.`);
+        }
+
+    }
+    _test_math({stage:'used', testString, expectedString, type, approx, msg, msgExtra, prop, prefix, suffix, extraStyle});
+}
+
+function test_math_computed(testString, expectedString, {approx, msg, msgExtra, type, prop, prefix, suffix, extraStyle={}}={}) {
+    if(type === undefined) type = "length";
+    if(!prop) {
+        switch(type) {
+            case "number":     prop = "transform"; prefix="scale("; suffix=")"; break;
+            case "integer":    prop = "z-index"; extraStyle.position="absolute"; break;
+            case "length":     prop = "flex-basis"; break;
+            case "angle":      prop = "transform"; prefix="rotate("; suffix=")"; break;
+            case "time":       prop = "transition-delay"; break;
+            case "resolution": prop = "image-resolution"; break;
+            case "flex":       prop = "grid-template-rows"; break;
+            default: throw Exception(`Value type '${type}' isn't capable of math.`);
+        }
+
+    }
+    _test_math({stage:'computed', testString, expectedString, type, approx, msg, msgExtra, prop, prefix, suffix, extraStyle});
+}
+
+function test_math_specified(testString, expectedString, {approx, msg, msgExtra, type, prop, prefix, suffix, extraStyle={}}={}) {
+    if(type === undefined) type = "length";
+    const stage = "specified";
+    if(!prop) {
+        switch(type) {
+            case "number":     prop = "transform"; prefix="scale("; suffix=")"; break;
+            case "integer":    prop = "z-index"; extraStyle.position="absolute"; break;
+            case "length":     prop = "flex-basis"; break;
+            case "angle":      prop = "transform"; prefix="rotate("; suffix=")"; break;
+            case "time":       prop = "transition-delay"; break;
+            case "resolution": prop = "image-resolution"; break;
+            case "flex":       prop = "grid-template-rows"; break;
+            default: throw Exception(`Value type '${type}' isn't capable of math.`);
+        }
+
+    }
+    // Find the test element
+    const testEl = document.getElementById('target');
+    if(testEl == null) throw "Couldn't find #target element to run tests on.";
+    // Then reset its styles
+    testEl.style = "";
+    for(const p in extraStyle) {
+        testEl.style[p] = extraStyle[p];
+    }
+    if(!msg) {
+        msg = `${testString} should be ${stage}-value-equivalent to ${expectedString}`;
+        if(msgExtra) msg += "; " + msgExtra;
+    }
+    let t = testString;
+    let e = expectedString;
+    if(prefix) {
+        t = prefix + t;
+        e = prefix + e;
+    }
+    if(suffix) {
+        t += suffix;
+        e += suffix;
+    }
+    test(()=>{
+        testEl.style[prop] = '';
+        testEl.style[prop] = t;
+        const usedValue = testEl.style[prop];
+        assert_not_equals(usedValue, '', `${testString} isn't valid in '${prop}'; got the default value instead.`);
+        testEl.style[prop] = '';
+        testEl.style[prop] = e;
+        const expectedValue = testEl.style[prop];
+        assert_not_equals(expectedValue, '', `${expectedString} isn't valid in '${prop}'; got the default value instead.`)
+        assert_equals(usedValue, expectedValue, `${testString} and ${expectedString} serialize to the same thing in ${stage} values.`);
+    }, msg);
+}
+
+/*
+All of these expect the testString to evaluate to a <number>.
+*/
+function test_plus_infinity(testString) {
+    test_math_used(testString, "calc(infinity)", {type:"number"});
+}
+function test_minus_infinity(testString) {
+    test_math_used(testString, "calc(-infinity)", {type:"number"});
+}
+function test_plus_zero(testString) {
+    test_math_used(`calc(1 / ${testString})`, "calc(infinity)", {type:"number"});
+}
+function test_minus_zero(testString) {
+    test_math_used(`calc(1 / ${testString})`, "calc(-infinity)", {type:"number"});
+}
+function test_nan(testString) {
+    // Make sure that it's NaN, not an infinity,
+    // by making sure that it's the same value both pos and neg.
+    test_math_used(testString, "calc(NaN)", {type:"number"});
+    test_math_used(`calc(-1 * ${testString})`, "calc(NaN)", {type:"number"});
+}
+
+
+function _test_math({stage, testEl, testString, expectedString, type, approx, msg, msgExtra, prop, prefix, suffix, extraStyle}={}) {
+    // Find the test element
+    if(!testEl) testEl = document.getElementById('target');
+    if(testEl == null) throw "Couldn't find #target element to run tests on.";
+    // Then reset its styles
+    testEl.style = "";
+    for(const p in extraStyle) {
+        testEl.style[p] = extraStyle[p];
+    }
+    if(!msg) {
+        msg = `${testString} should be ${stage}-value-equivalent to ${expectedString}`;
+        if(msgExtra) msg += "; " + msgExtra;
+    }
+    let t = testString;
+    let e = expectedString;
+    if(prefix) {
+        t = prefix + t;
+        e = prefix + e;
+    }
+    if(suffix) {
+        t += suffix;
+        e += suffix;
+    }
+    test(()=>{
+        testEl.style[prop] = '';
+        const defaultValue = getComputedStyle(testEl)[prop];
+        testEl.style[prop] = t;
+        const usedValue = getComputedStyle(testEl)[prop];
+        assert_not_equals(usedValue, defaultValue, `${testString} isn't valid in '${prop}'; got the default value instead.`);
+        testEl.style[prop] = '';
+        testEl.style[prop] = e;
+        const expectedValue = getComputedStyle(testEl)[prop];
+        assert_not_equals(expectedValue, defaultValue, `${expectedString} isn't valid in '${prop}'; got the default value instead.`)
+        if(approx && (type == "number" || type == "angle")){
+            let parsedUsed = usedValue.split('(')[1].split(')')[0].split(',').map(parseFloat);
+            let parsedExpected = expectedValue.split('(')[1].split(')')[0].split(',').map(parseFloat);
+            assert_array_approx_equals(parsedUsed, parsedExpected, approx, `${testString} and ${expectedString} ${approx} serialize to the same thing in ${stage} values.`);
+        } else {
+            assert_equals(usedValue, expectedValue, `${testString} and ${expectedString} serialize to the same thing in ${stage} values.`);
+        }
+    }, msg);
+}