[DevTools] JSONView parsing smarter

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

Index: third_party/WebKit/Source/devtools/front_end/formatter_worker/RelaxedJSONParser.js
diff --git a/third_party/WebKit/Source/devtools/front_end/formatter_worker/RelaxedJSONParser.js b/third_party/WebKit/Source/devtools/front_end/formatter_worker/RelaxedJSONParser.js
new file mode 100644
index 0000000000000000000000000000000000000000..2c0b38042f2d4a54fe37accb73e5bcdc9c4c7409
--- /dev/null
+++ b/third_party/WebKit/Source/devtools/front_end/formatter_worker/RelaxedJSONParser.js
@@ -0,0 +1,201 @@
+// 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.
+
+WebInspector.RelaxedJSONParser = {};
+
+/** @enum {string} */
+WebInspector.RelaxedJSONParser.States = {
+    ExpectKey: "ExpectKey",
+    ExpectValue: "ExpectValue"
+};
+
+/** @enum {*} */
+WebInspector.RelaxedJSONParser.Keywords = {
+    "NaN": NaN,
+    "true": true,
+    "false": false,
+    "Infinity": Infinity,
+    "undefined": undefined,
+    "null": null
+};
+
+/**
+ * @param {string} content
+ * @return {*}
+ */
+WebInspector.RelaxedJSONParser.parse = function(content)
+{
+    var Keywords = WebInspector.RelaxedJSONParser.Keywords;
+    var States = WebInspector.RelaxedJSONParser.States;
+    content = "(" + content + ")";
+
+    try {
+        var root = acorn.parse(content, {});
+    } catch (e) {
+        return null;
+    }
+
+    var walker = new WebInspector.ESTreeWalker(beforeVisit, afterVisit);
+
+    var rootTip = [];
+
+    /** @type {!Array.<!WebInspector.RelaxedJSONParser.Context>} */
+    var stack = [];
+
+    var stackData = /** @type {!WebInspector.RelaxedJSONParser.Context} */ ({
+        key: 0,
+        tip: rootTip,
+        state: States.ExpectValue,
+        parentIsArray: true
+    });
+
+    walker.setWalkNulls(true);
+    var hasExpression = false;
+
+    walker.walk(root);
+
+    if (hasExpression)
+        return null;
+    return rootTip.length ? rootTip[0] : null;
+
+    /**
+     * @param {!WebInspector.RelaxedJSONParser.Context} newStack
+     */
+    function pushStack(newStack)
+    {
+        stack.push(stackData);
+        stackData = newStack;
+    }
+
+    function popStack()
+    {
+        stackData = stack.pop();
+    }
+
+    /**
+     * @param {*} value
+     */
+    function applyValue(value)
+    {
+        stackData.tip[stackData.key] = value;
+        if (stackData.parentIsArray)
+            stackData.key++;
+        else
+            stackData.state = null;
+    }
+
+    /**
+     * @param {!ESTree.Node} node
+     * @return {!Object|undefined}
+     */
+    function beforeVisit(node)
+    {
+        switch (node.type) {
+        case "ObjectExpression":
+            var newTip = {};
+            applyValue(newTip);
+
+            pushStack(/** @type {!WebInspector.RelaxedJSONParser.Context} */ ({
+                key: null,
+                tip: newTip,
+                state: null,
+                parentIsArray: false
+            }));
+            break;
+        case "ArrayExpression":
+            var newTip = [];
+            applyValue(newTip);
+
+            pushStack(/** @type {!WebInspector.RelaxedJSONParser.Context} */ ({
+                key: 0,
+                tip: newTip,
+                state: States.ExpectValue,
+                parentIsArray: true
+            }));
+            break;
+        case "Property":
+            stackData.state = States.ExpectKey;
+            break;
+        case "Literal":
+            if (stackData.state === States.ExpectKey) {
+                stackData.key = node.value;
+                stackData.state = States.ExpectValue;
+            } else if (stackData.state === States.ExpectValue) {
+                applyValue(extractValue(node));
+                return WebInspector.ESTreeWalker.SkipSubtree;
+            }
+            break;
+        case "Identifier":
+            if (stackData.state === States.ExpectKey) {
+                stackData.key = /** @type {string} */ (node.name);
+                stackData.state = States.ExpectValue;
+            } else if (stackData.state === States.ExpectValue) {
+                applyValue(extractValue(node));
+                return WebInspector.ESTreeWalker.SkipSubtree;
+            }
+            break;
+        case "UnaryExpression":
+            if (stackData.state === States.ExpectValue) {
+                applyValue(extractValue(node));
+                return WebInspector.ESTreeWalker.SkipSubtree;
+            }
+            break;
+        case "Program":
+        case "ExpressionStatement":
+            break;
+        default:
+            if (stackData.state === States.ExpectValue)
+                applyValue(extractValue(node));
+            return WebInspector.ESTreeWalker.SkipSubtree;
+        }
+    }
+
+    /**
+     * @param {!ESTree.Node} node
+     */
+    function afterVisit(node)
+    {
+        if (node.type === "ObjectExpression" || node.type === "ArrayExpression")
+            popStack();
+    }
+
+    /**
+     * @param {!ESTree.Node} node
+     * @return {*}
+     */
+    function extractValue(node)
+    {
+        var isNegative = false;
+        var originalNode = node;
+        var value;
+        if (node.type === "UnaryExpression" && (node.operator === "-" || node.operator === "+")) {
+            if (node.operator === "-")
+                isNegative = true;
+            node = /** @type {!ESTree.Node} */ (node.argument);
+        }
+
+        if (node.type === "Literal") {
+            value = node.value;
+        } else if (node.type === "Identifier" && Keywords.hasOwnProperty(node.name)) {
+            value = Keywords[node.name];
+        } else {
+            hasExpression = true;
+            return content.substring(originalNode.start, originalNode.end);
+        }
+
+        if (isNegative) {
+            if (typeof value !== "number") {
+                hasExpression = true;
+                return content.substring(originalNode.start, originalNode.end);
+            }
+            value = -(value);
+        }
+        return value;
+    }
+}
+
+/**
+ * @typedef {!{key: (number|string), tip: (!Array|!Object), state: ?WebInspector.RelaxedJSONParser.States, parentIsArray: boolean}}
+ */
+WebInspector.RelaxedJSONParser.Context;