DevTools: [STRUCT] edit SASS through SourceMaps

Source/devtools/front_end/bindings/SASSSupport.js

Index: Source/devtools/front_end/bindings/SASSSupport.js
diff --git a/Source/devtools/front_end/bindings/SASSSupport.js b/Source/devtools/front_end/bindings/SASSSupport.js
new file mode 100644
index 0000000000000000000000000000000000000000..c1aa838fe462a5a5b87029b895ae27619cc53b86
--- /dev/null
+++ b/Source/devtools/front_end/bindings/SASSSupport.js
@@ -0,0 +1,494 @@
+// Copyright 2015 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.
+
+WebInspector.SASSSupport = {
+    insertPropertyAfter: function(property, after)
+    {
+        var rule = after.parent;
+        rule.insertPropertyAfter(property, after);
+
+        var ast = after.root();
+        var oldRange = WebInspector.TextRange.createFromLocation(after.range.endLine, after.range.endColumn);
+        var indent = (new WebInspector.TextRange(after.range.startLine, 0, after.range.startLine, after.range.startColumn)).extract(ast.text);
+        if (!/^\s+$/.test(indent)) indent = "";
+
+        // Split property addition into chunks to preserve mappings.
+        var newText = String.sprintf("\n%s%s: %s;", indent, property.name.text, property.value.text);
+        return new WebInspector.SourceEdit(ast.url, oldRange, "", newText);
+    },
+
+    insertPropertyBefore: function(property, before)
+    {
+        var rule = before.parent;
+        rule.insertPropertyAfter(property, null);
+
+        var ast = before.root();
+        var oldRange = WebInspector.TextRange.createFromLocation(before.range.startLine, before.range.startColumn);
+        var indent = (new WebInspector.TextRange(before.range.startLine, 0, before.range.startLine, before.range.startColumn)).extract(ast.text);
+        if (!/^\s+$/.test(indent)) indent = "";
+
+        // Split property addition into chunks to preserve mappings.
+        var newText = String.sprintf("%s: %s;\n%s", property.name.text, property.value.text, indent);
+        return new WebInspector.SourceEdit(ast.url, oldRange, "", newText);
+    },
+
+    removeProperty: function(property)
+    {
+        var rule = property.parent;
+        var ast = property.root();
+        rule.removeProperty(property);
+
+        var lineRemoveRange = new WebInspector.TextRange(property.range.startLine, 0, property.range.endLine + 1, 0);
+        var oldRange = (lineRemoveRange.extract(ast.text).trim() === property.range.extract(ast.text).trim()) ? lineRemoveRange : property.range;
+        return new WebInspector.SourceEdit(ast.url, oldRange, oldRange.extract(ast.text), "");
+    },
+
+    setText: function(node, newText)
+    {
+        console.assert(node.type === "TextNode", "Cannot set text to node of type " + node.type);
+        node.text = newText;
+        var ast = node.root();
+        return new WebInspector.SourceEdit(ast.url, node.range, node.range.extract(ast.text), newText);
+    },
+
+    toggleDisabled: function(property, disabled)
+    {
+        property.disabled = disabled;
+        var ast = property.root();
+        if (disabled) {
+            var oldRange1 = WebInspector.TextRange.createFromLocation(property.range.startLine, property.range.startColumn);
+            var edit1 = new WebInspector.SourceEdit(ast.url, oldRange1, "", "/* ");
+            var oldRange2 = WebInspector.TextRange.createFromLocation(property.range.endLine, property.range.endColumn);
+            var edit2 = new WebInspector.SourceEdit(ast.url, oldRange2, "", " */");
+            return [edit1, edit2];
+        }
+        var oldRange1 = new WebInspector.TextRange(property.range.startLine, property.range.startColumn, property.range.startLine, property.name.range.startColumn);
+        var text = ast.text;
+        var edit1 = new WebInspector.SourceEdit(ast.url, oldRange1, oldRange1.extract(text), "");
+        var oldRange2 = new WebInspector.TextRange(property.range.endLine, property.range.endColumn - 2, property.range.endLine, property.range.endColumn);
+        var edit2 = new WebInspector.SourceEdit(ast.url, oldRange2, "*/", "");
+        return [edit1, edit2];
+    },
+}
+
+WebInspector.SASSSupport.parseCSS = function(url, text)
+{
+    var parser = new WebInspector.CSSParser();
+    return parsePromise = parser.parsePromise(text)
+        .then(onParsed.bind(this));
+
+    function onParsed(parsedCSS)
+    {
+        parser.dispose();
+        var rules = [];
+        for (var i = 0; i < parsedCSS.length; ++i) {
+            var rule = parsedCSS[i];
+            if (!rule.properties)
+                continue;
+            var properties = [];
+            for (var j = 0; j < rule.properties.length; ++j) {
+                var cssProperty = rule.properties[j];
+                var name = new WebInspector.SASSSupport.TextNode(cssProperty.name, WebInspector.TextRange.fromObject(cssProperty.nameRange));
+                var value = new WebInspector.SASSSupport.TextNode(cssProperty.value, WebInspector.TextRange.fromObject(cssProperty.valueRange));
+                var property = new WebInspector.SASSSupport.Property(name, value, WebInspector.TextRange.fromObject(cssProperty.range));
+                property.disabled = cssProperty.disabled;
+                properties.push(property);
+            }
+            rules.push(new WebInspector.SASSSupport.Rule(rule.selectorText, properties));
+        }
+        return new WebInspector.SASSSupport.AST(url, text, rules);
+    }
+},
+
+WebInspector.SASSSupport.parseSASS = function(url, text, tokenizerFactory)
+{
+    var result = WebInspector.SASSSupport._innerParseSASS(text, tokenizerFactory);
+
+    var rules = [
+        new WebInspector.SASSSupport.Rule("variables", result.variables),
+        new WebInspector.SASSSupport.Rule("properties", result.properties),
+        new WebInspector.SASSSupport.Rule("mixins", result.mixins)
+    ];
+
+    return new WebInspector.SASSSupport.AST(url, text, rules);
+}
+
+WebInspector.SASSSupport.SCSSParserStates = {
+    Initial: "Initial",
+    PropertyName: "PropertyName",
+    PropertyValue: "PropertyValue",
+    VariableName: "VariableName",
+    VariableValue: "VariableValue",
+    MixinInclude: "MixinInclude",
+    MixinValue: "MixinValue"
+}
+
+WebInspector.SASSSupport._innerParseSASS = function(text, tokenizerFactory)
+{
+    var lines = text.split("\n");
+    var properties = [];
+    var variables = [];
+    var mixins = [];
+
+    var States = WebInspector.SASSSupport.SCSSParserStates;
+    var state = States.Initial;
+    var propertyName, propertyValue;
+    var variableName, variableValue;
+    var mixinName, mixinValue;
+    var UndefTokenType = {};
+
+    /**
+     * @param {string} tokenValue
+     * @param {?string} tokenTypes
+     * @param {number} column
+     * @param {number} newColumn
+     */
+    function processToken(tokenValue, tokenTypes, column, newColumn)
+    {
+        var tokenType = tokenTypes ? tokenTypes.split(" ").keySet() : UndefTokenType;
+        switch (state) {
+        case States.Initial:
+            if (tokenType["css-variable-2"]) {
+                variableName = new WebInspector.SASSSupport.TextNode(tokenValue, new WebInspector.TextRange(lineNumber, column, lineNumber, newColumn));
+                state = States.VariableName;
+            } else if (tokenType["css-property"] || tokenType["css-meta"]) {
+                propertyName = new WebInspector.SASSSupport.TextNode(tokenValue, new WebInspector.TextRange(lineNumber, column, lineNumber, newColumn));
+                state = States.PropertyName;
+            } else if (tokenType["css-def"] && tokenValue === "@include") {
+                mixinName = new WebInspector.SASSSupport.TextNode(tokenValue, new WebInspector.TextRange(lineNumber, column, lineNumber, newColumn));
+                state = States.MixinInclude;
+            } else if (tokenType["css-comment"]) {
+                // The |processToken| is called per-line, so no token spans more then one line.
+                // Support only a one-line comments.
+                if (tokenValue.substring(0, 2) !== "/*" || tokenValue.substring(tokenValue.length - 2) !== "*/")
+                    break;
+                var uncommentedText = tokenValue.substring(2, tokenValue.length - 2);
+                var fakeRule = "a{\n" + uncommentedText + "}";
+                disabledRules = [];
+                var result = WebInspector.SASSSupport._innerParseSASS(fakeRule, tokenizerFactory);
+                if (result.properties.length === 1 && result.variables.length === 0 && result.mixins.length === 0) {
+                    var disabledProperty = result.properties[0];
+                    // We should offset property to current coordinates.
+                    var offset = column + 2;
+                    disabledProperty.disabled = true;
+                    disabledProperty.range = WebInspector.TextRange.createFromLocation(lineNumber, column);
+                    disabledProperty.range.endColumn = newColumn;
+                    disabledProperty.name.range.startColumn += offset;
+                    disabledProperty.name.range.endColumn += offset;
+                    disabledProperty.value.range.startColumn += offset;
+                    disabledProperty.value.range.endColumn += offset;
+                    properties.push(disabledProperty);
+                }
+            }
+            break;
+        case States.VariableName:
+            if (tokenValue === ")" && tokenType === UndefTokenType) {
+                state = States.Initial;
+            } else if (tokenValue === ":" && tokenType === UndefTokenType) {
+                state = States.VariableValue;
+                variableValue = new WebInspector.SASSSupport.TextNode("", WebInspector.TextRange.createFromLocation(lineNumber, newColumn));
+            } else if (tokenType !== UndefTokenType) {
+                state = States.Initial;
+            }
+            break;
+        case States.VariableValue:
+            if (tokenValue === ";" && tokenType === UndefTokenType) {
+                variableValue.range.endLine = lineNumber;
+                variableValue.range.endColumn = column;
+                var variable = new WebInspector.SASSSupport.Property(variableName, variableValue, variableName.range.clone());
+                variable.range.endLine = lineNumber;
+                variable.range.endColumn = newColumn;
+                variables.push(variable);
+                state = States.Initial;
+            } else {
+                variableValue.text += tokenValue;
+            }
+            break;
+        case States.PropertyName:
+            if (tokenValue === ":" && tokenType === UndefTokenType) {
+                state = States.PropertyValue;
+                propertyName.range.endLine = lineNumber;
+                propertyName.range.endColumn = column;
+                propertyValue = new WebInspector.SASSSupport.TextNode("", WebInspector.TextRange.createFromLocation(lineNumber, newColumn));
+            } else if (tokenType["css-property"]) {
+                propertyName.text += tokenValue;
+            }
+            break;
+        case States.PropertyValue:
+            if (tokenValue === ";" && tokenType === UndefTokenType) {
+                propertyValue.range.endLine = lineNumber;
+                propertyValue.range.endColumn = column;
+                var property = new WebInspector.SASSSupport.Property(propertyName, propertyValue, propertyName.range.clone());
+                property.range.endLine = lineNumber;
+                property.range.endColumn = newColumn;
+                properties.push(property);
+                state = States.Initial;
+            } else {
+                propertyValue.text += tokenValue;
+            }
+            break;
+        case States.MixinInclude:
+            if (tokenValue === "(" && tokenType === UndefTokenType) {
+                state = States.MixinValue;
+                mixinValue = new WebInspector.SASSSupport.TextNode("", WebInspector.TextRange.createFromLocation(lineNumber, newColumn));
+            } else if (tokenValue === ";" && tokenType === UndefTokenType) {
+                state = States.Initial;
+                if (mixinValue) {
+                    var mixin = new WebInspector.SASSSupport.Property(mixinName, mixinValue);
+                    mixins.push(mixin);
+                }
+                mixinValue = null;
+            } else {
+                mixinName.text += tokenValue;
+            }
+            break;
+        case States.MixinValue:
+            if (tokenValue === ")" && tokenType === UndefTokenType) {
+                state = States.MixinInclude;
+                mixinValue.range.endLine = lineNumber;
+                mixinValue.range.endColumn = column;
+            } else {
+                mixinValue.text += tokenValue;
+            }
+            break;
+        default:
+            console.assert(false, "Unknown SASS parser state.");
+        }
+    }
+    var tokenizer = tokenizerFactory.createTokenizer("text/x-scss");
+    var lineNumber;
+    for (lineNumber = 0; lineNumber < lines.length; ++lineNumber) {
+        var line = lines[lineNumber];
+        tokenizer(line, processToken);
+    }
+    return {
+        variables: variables,
+        properties: properties,
+        mixins: mixins
+    };
+}
+
+WebInspector.SASSSupport.Node = function(type)
+{
+    this.type = type;
+}
+
+WebInspector.SASSSupport.Node.prototype = {
+    root: function()
+    {
+        if (this._root)
+            return this._root;
+        this._root = this;
+        while (this._root.parent)
+            this._root = this._root.parent;
+        return this._root;
+    }
+}
+
+WebInspector.SASSSupport.TextNode = function(text, range)
+{
+    WebInspector.SASSSupport.Node.call(this, "TextNode");
+    this.text = text;
+    this.range = range;
+    this.parent = null;
+}
+
+WebInspector.SASSSupport.TextNode.prototype = {
+    clone: function()
+    {
+        return new WebInspector.SASSSupport.TextNode(this.text, this.range.clone());
+    },
+
+    __proto__: WebInspector.SASSSupport.Node.prototype
+}
+
+WebInspector.SASSSupport.Property = function(name, value, range)
+{
+    WebInspector.SASSSupport.Node.call(this, "Property");
+    this.name = name;
+    this.value = value;
+    this.range = range;
+    this.name.parent = this;
+    this.value.parent = this;
+    this.parent = null;
+    this.disabled = false;
+}
+
+WebInspector.SASSSupport.Property.prototype = {
+    clone: function()
+    {
+        return new WebInspector.SASSSupport.Property(this.name.clone(), this.value.clone(), this.range.clone());
+    },
+
+    __proto__: WebInspector.SASSSupport.Node.prototype
+}
+
+WebInspector.SASSSupport.Rule = function(selector, properties)
+{
+    WebInspector.SASSSupport.Node.call(this, "Rule");
+    this.selector = selector;
+    this.properties = properties;
+    this.parent = null;
+    for (var i = 0; i < this.properties.length; ++i)
+        this.properties[i].parent = this;
+}
+
+WebInspector.SASSSupport.Rule.prototype = {
+    insertPropertyAfter: function(property, after)
+    {
+        var index = this.properties.indexOf(after);
+        this.properties.splice(index + 1, 0, property);
+        property.parent = this;
+    },
+
+    removeProperty: function(property)
+    {
+        var index = this.properties.indexOf(property);
+        this.properties.splice(index, 1);
+        property.parent = null;
+    },
+
+    __proto__: WebInspector.SASSSupport.Node.prototype
+}
+
+WebInspector.SASSSupport.AST = function(url, text, rules)
+{
+    WebInspector.SASSSupport.Node.call(this, "AST");
+    this.url = url;
+    this.rules = rules;
+    for (var i = 0; i < rules.length; ++i) {
+        rules[i].before = i > 0 ? rules[i - 1] : null;
+        rules[i].after = i < rules.length - 1 ? rules[i + 1] : null;
+        rules[i].parent = this;
+    }
+    this.text = text;
+}
+
+WebInspector.SASSSupport.AST.prototype.__proto__ = WebInspector.SASSSupport.Node.prototype;
+
+WebInspector.SASSSourceMapping.diffModels = function(oldAST, newAST)
+{
+    if (oldAST.rules.length !== newAST.rules.length)
+        throw new Error("not implemented for rule diff.");
+    var structuralDiff = [];
+    var aToB = new Map();
+    var bToA = new Map();
+    for (var i = 0; i < oldAST.rules.length; ++i) {
+        var oldRule = oldAST.rules[i];
+        var newRule = newAST.rules[i];
+        var removedSet = new Set();
+        var addedSet = new Set();
+        if (oldRule.properties.length !== newRule.properties.length)
+            WebInspector.SASSSourceMapping.cssPropertiesDiff(oldRule.properties, newRule.properties, removedSet, addedSet);
+
+        // Compute PropertyRemoved diff entries.
+        for (var property of removedSet.values()) {
+            structuralDiff.push({
+                type: "PropertyRemoved",
+                property: property
+            });
+        }
+
+        // Map similar properties.
+        var p1 = 0;
+        var p2 = 0;
+        while (p1 < oldRule.properties.length && p2 < newRule.properties.length) {
+            if (removedSet.has(oldRule.properties[p1])) {
+                ++p1;
+                continue;
+            }
+            if (addedSet.has(newRule.properties[p2])) {
+                ++p2;
+                continue;
+            }
+            var oldProperty = oldRule.properties[p1++];
+            var newProperty = newRule.properties[p2++];
+            aToB.set(oldProperty, newProperty);
+            bToA.set(newProperty, oldProperty);
+            if (oldProperty.name.text !== newProperty.name.text) {
+                structuralDiff.push({
+                    type: "NameChanged",
+                    property: newProperty,
+                });
+            }
+            if (oldProperty.value.text !== newProperty.value.text) {
+                structuralDiff.push({
+                    type: "ValueChanged",
+                    property: newProperty,
+                });
+            }
+            if (oldProperty.disabled !== newProperty.disabled) {
+                structuralDiff.push({
+                    type: "toggleDisabled",
+                    property: newProperty,
+                });
+            }
+        }
+
+        // Compute PropertyAdded diff entries.
+        var firstValidProperty = null;
+        for (var j = 0; j < newRule.properties.length; ++j) {
+            var property = newRule.properties[j];
+            if (!addedSet.has(property)) {
+                firstValidProperty = property;
+                break;
+            }
+        }
+        var lastValidProperty = null;
+        for (var j = 0; j < newRule.properties.length; ++j) {
+            var property = newRule.properties[j];
+            if (!addedSet.has(property)) {
+                lastValidProperty = property;
+                continue;
+            }
+            var diff = {
+                type: "PropertyAdded",
+                property: property,
+            };
+            if (lastValidProperty)
+                diff.after = lastValidProperty;
+            else if (firstValidProperty)
+                diff.before = firstValidProperty;
+            structuralDiff.push(diff);
+        }
+    }
+    return {
+        aToB: aToB,
+        bToA: bToA,
+        structuralDiff
+    };
+}
+
+WebInspector.SASSSourceMapping.cssPropertiesDiff = function(properties1, properties2, removedSet, addedSet)
+{
+    var charCode = 33;
+    var encodedProperties = new Map();
+    var lines1 = [];
+    for (var i = 0; i < properties1.length; ++i)
+        lines1.push(properties1[i].name.text + ":" + properties1[i].value.text);
+
+    var lines2 = [];
+    for (var i = 0; i < properties2.length; ++i)
+        lines2.push(properties2[i].name.text + ":" + properties2[i].value.text);
+
+    var diff = WebInspector.Diff.lineDiff(lines1, lines2);
+    var p1 = 0, p2 = 0;
+    for (var i = 0; i < diff.length; ++i) {
+        var token = diff[i];
+        if (token[0] === 0) {
+            p1 += token[1].length;
+            p2 += token[1].length;
+        } else if (token[0] === -1) {
+            for (var j = 0; j < token[1].length; ++j) {
+                var property = properties1[p1++];
+                removedSet.add(property);
+            }
+        } else {
+            for (var j = 0; j < token[1].length; ++j) {
+                var property = properties2[p2++];
+                addedSet.add(property);
+            }
+        }
+    }
+}