DevTools: [SASS] introduce Gonzales-PE for SCSS parsing

third_party/WebKit/Source/devtools/front_end/formatter_worker/SCSSParser.js

Index: third_party/WebKit/Source/devtools/front_end/formatter_worker/SCSSParser.js
diff --git a/third_party/WebKit/Source/devtools/front_end/formatter_worker/SCSSParser.js b/third_party/WebKit/Source/devtools/front_end/formatter_worker/SCSSParser.js
new file mode 100644
index 0000000000000000000000000000000000000000..9a10a54521ea1e30b751f12d1f8419c5617b127b
--- /dev/null
+++ b/third_party/WebKit/Source/devtools/front_end/formatter_worker/SCSSParser.js
@@ -0,0 +1,225 @@
+// Copyright 2016 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.
+
+/**
+ * @constructor
+ */
+WebInspector.SCSSParser = function()
+{
+}
+
+/**
+ * @constructor
+ */
+WebInspector.SCSSParser.Result = function()
+{
+    this.properties = [];
+    this.variables = [];
+    this.mixins = [];
+}
+
+WebInspector.SCSSParser.prototype = {
+    /**
+     * @param {string} content
+     * @return {!Promise<!WebInspector.SCSSParser.Result>}
+     */
+    parse: function(content)
+    {
+        this._content = content;

[dgozman, 2016/04/29 01:16:17]

Stateless!

[lushnikov, 2016/04/29 01:55:41]

Done.

+        return self.runtime.loadModulePromise("gonzales")

[dgozman, 2016/04/29 01:16:17]

Let's put this file into gonzales module and have a per-mimetype extension point
in FormatterWorker.

[lushnikov, 2016/04/29 01:55:42]

Done.

+            .then(this._innerParse.bind(this, content))
+            .catch(onError)
+
+        /**
+         * @param {*} error
+         */
+        function onError(error)
+        {
+            console.error(error);
+            return new WebInspector.SCSSParser.Result();
+        }
+    },
+
+    /**
+     * @param {string} content
+     * @return {!WebInspector.SCSSParser.Result}
+     */
+    _innerParse: function(content)
+    {
+        var result = new WebInspector.SCSSParser.Result();
+        var ast = null;
+        try {
+            ast = gonzales.parse(content, {syntax: "scss"});
+        } catch (e) {
+            return result;
+        }
+
+        var extractedNodes = [];
+        WebInspector.SCSSParser.extractNodes(ast, extractedNodes);
+
+        for (var node of extractedNodes) {
+            if (node.type === "declaration")
+                this._handleDeclaration(node, result);
+            else if (node.type === "include")
+                this._handleInclude(node, result);
+            else if (node.type === "multilineComment" && node.start.line === node.end.line)
+                this._handleComment(node, result);
+        }
+        return result;
+    },
+
+    /**
+     * @param {!Gonzales.Node} node
+     * @param {!WebInspector.SCSSParser.Result} result
+     */
+    _handleDeclaration: function(node, result)
+    {
+        var propertyNode = node.content.find(node => node.type === "property");
+        var delimeterNode = node.content.find(node => node.type === "propertyDelimiter");
+        var valueNode = node.content.find(node => node.type === "value");
+        if (!propertyNode || !delimeterNode || !valueNode)
+            return;
+
+        var nameRange = new WebInspector.TextRange(propertyNode.start.line - 1, propertyNode.start.column - 1, delimeterNode.start.line - 1, delimeterNode.start.column - 1);
+        var valueRange = new WebInspector.TextRange(delimeterNode.end.line - 1, delimeterNode.end.column, valueNode.end.line - 1, valueNode.end.column);
+        var range = /** @type {!WebInspector.TextRange} */(node.declarationRange);
+
+        var property = new WebInspector.SCSSParser.Property(range, nameRange, valueRange, false);
+        var isVariable = !!propertyNode.content.find(node => node.type === "variable");
+        if (isVariable)
+            result.variables.push(property);
+        else
+            result.properties.push(property);
+    },
+
+    /**
+     * @param {!Gonzales.Node} node
+     * @param {!WebInspector.SCSSParser.Result} result
+     */
+    _handleInclude: function(node, result)
+    {
+        var mixinName = node.content.find(node => node.type === "ident");
+        if (!mixinName)
+            return;
+        var nameRange = WebInspector.SCSSParser.rangeFromNode(mixinName);
+        var mixinArguments = node.content.find(node => node.type === "arguments");
+        if (!mixinArguments)
+            return;
+        var parameters = mixinArguments.content.filter(node => node.type !== "delimiter" && node.type !== "space");

[dgozman, 2016/04/29 01:16:17]

Can we whitelist them?

[lushnikov, 2016/04/29 01:55:41]

There are multiple different nodes: "15px" would be reported as dimensions node,
"red" as identifier, "#FFF" as color.. I'd rather blacklist things - fetching
more is harmless.

+        for (var parameter of parameters) {
+            var range = WebInspector.SCSSParser.rangeFromNode(node);
+            var valueRange = WebInspector.SCSSParser.rangeFromNode(parameter);
+            var property = new WebInspector.SCSSParser.Property(range, nameRange, valueRange, false);
+            result.mixins.push(property);
+        }
+    },
+
+    /**
+     * @param {!Gonzales.Node} node
+     * @param {!WebInspector.SCSSParser.Result} result
+     */
+    _handleComment: function(node, result)
+    {
+        if (node.start.line !== node.end.line)
+            return;
+        var innerText = /** @type {string} */(node.content);
+        var innerResult = this._innerParse(innerText);
+        if (innerResult.properties.length !== 1 || innerResult.variables.length !== 0 || innerResult.mixins.length !== 0)
+            return;
+        var property = innerResult.properties[0];
+        var disabledProperty = property.rebaseInsideOneLineComment(node);
+        result.properties.push(disabledProperty);
+    },
+}
+
+/**
+ * @param {!Gonzales.Node} node
+ * @return {!WebInspector.TextRange}
+ */
+WebInspector.SCSSParser.rangeFromNode = function(node)
+{
+    return new WebInspector.TextRange(node.start.line - 1, node.start.column - 1, node.end.line - 1, node.end.column);
+}
+
+/**
+ * @constructor
+ * @param {!WebInspector.TextRange} range
+ * @param {!WebInspector.TextRange} nameRange
+ * @param {!WebInspector.TextRange} valueRange
+ * @param {boolean} disabled
+ */
+WebInspector.SCSSParser.Property = function(range, nameRange, valueRange, disabled)
+{
+    this.range = range;
+    this.name = nameRange;
+    this.value = valueRange;
+    this.disabled = disabled;
+}
+
+WebInspector.SCSSParser.Property.prototype = {
+    /**
+     * @param {!Gonzales.Node} commentNode
+     * @return {!WebInspector.SCSSParser.Property}
+     */
+    rebaseInsideOneLineComment: function(commentNode)
+    {
+        var lineOffset = commentNode.start.line - 1;
+        var columnOffset = commentNode.start.column - 1 + 2;

[dgozman, 2016/04/29 01:16:17]

// account 2 for "/*"

[lushnikov, 2016/04/29 01:55:41]

Done.

+        var range = WebInspector.SCSSParser.rangeFromNode(commentNode);
+        var name = rebaseRange(this.name, lineOffset, columnOffset);
+        var value = rebaseRange(this.value, lineOffset, columnOffset);
+        return new WebInspector.SCSSParser.Property(range, name, value, true);
+
+        /**
+         * @param {!WebInspector.TextRange} range
+         * @param {number} lineOffset
+         * @param {number} columnOffset
+         * @return {!WebInspector.TextRange}
+         */
+        function rebaseRange(range, lineOffset, columnOffset)
+        {
+            return new WebInspector.TextRange(range.startLine + lineOffset, range.startColumn + columnOffset, range.endLine + lineOffset, range.endColumn + columnOffset);
+        }
+    }
+}
+
+/**
+ * @param {!Gonzales.Node} node
+ * @param {!Array<!Gonzales.Node>} output
+ */
+WebInspector.SCSSParser.extractNodes = function(node, output)
+{
+    if (!Array.isArray(node.content))
+        return;
+    var lastDeclaration = null;
+    for (var i = 0; i < node.content.length; ++i) {
+        var child = node.content[i];
+        if (child.type === "declarationDelimiter" && lastDeclaration) {
+            lastDeclaration.declarationRange.endLine = child.end.line - 1;
+            lastDeclaration.declarationRange.endColumn = child.end.column;
+            lastDeclaration = null;
+        }
+        if (child.type === "include" || child.type === "declaration" || child.type === "multilineComment")
+            output.push(child);
+        if (child.type === "declaration") {
+            lastDeclaration = child;
+            lastDeclaration.declarationRange = WebInspector.TextRange.createFromLocation(child.start.line - 1, child.start.column - 1);
+        }
+        WebInspector.SCSSParser.extractNodes(child, output);
+    }
+    if (lastDeclaration) {
+        lastDeclaration.declarationRange.endLine = node.end.line - 1;
+        lastDeclaration.declarationRange.endColumn = node.end.column - 1;
+    }
+}
+
+/**
+ * @param {string} text
+ */
+WebInspector.SCSSParser.parse = function(text)
+{
+    var parser = new WebInspector.SCSSParser();
+    parser.parse(text).then(postMessage);
+}
+