import FIREFOX_52_6_0esr_RELEASE from mozilla-esr52 hg repo

devtools/client/webconsole/net/utils/json.js

@@ -0,0 +1,234 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+"use strict";
+
+// List of JSON content types.
+const contentTypes = {
+  "text/plain": 1,
+  "text/javascript": 1,
+  "text/x-javascript": 1,
+  "text/json": 1,
+  "text/x-json": 1,
+  "application/json": 1,
+  "application/x-json": 1,
+  "application/javascript": 1,
+  "application/x-javascript": 1,
+  "application/json-rpc": 1
+};
+
+// Implementation
+var Json = {};
+
+/**
+ * Parsing JSON
+ */
+Json.parseJSONString = function (jsonString) {
+  if (!jsonString.length) {
+    return null;
+  }
+
+  let regex, matches;
+
+  let first = firstNonWs(jsonString);
+  if (first !== "[" && first !== "{") {
+    // This (probably) isn't pure JSON. Let's try to strip various sorts
+    // of XSSI protection/wrapping and see if that works better.
+
+    // Prototype-style secure requests
+    regex = /^\s*\/\*-secure-([\s\S]*)\*\/\s*$/;
+    matches = regex.exec(jsonString);
+    if (matches) {
+      jsonString = matches[1];
+
+      if (jsonString[0] === "\\" && jsonString[1] === "n") {
+        jsonString = jsonString.substr(2);
+      }
+
+      if (jsonString[jsonString.length - 2] === "\\" &&
+        jsonString[jsonString.length - 1] === "n") {
+        jsonString = jsonString.substr(0, jsonString.length - 2);
+      }
+    }
+
+    // Google-style (?) delimiters
+    if (jsonString.indexOf("&&&START&&&") !== -1) {
+      regex = /&&&START&&&([\s\S]*)&&&END&&&/;
+      matches = regex.exec(jsonString);
+      if (matches) {
+        jsonString = matches[1];
+      }
+    }
+
+    // while(1);, for(;;);, and )]}'
+    regex = /^\s*(\)\]\}[^\n]*\n|while\s*\(1\);|for\s*\(;;\);)([\s\S]*)/;
+    matches = regex.exec(jsonString);
+    if (matches) {
+      jsonString = matches[2];
+    }
+
+    // JSONP
+    regex = /^\s*([A-Za-z0-9_$.]+\s*(?:\[.*\]|))\s*\(([\s\S]*)\)/;
+    matches = regex.exec(jsonString);
+    if (matches) {
+      jsonString = matches[2];
+    }
+  }
+
+  try {
+    return JSON.parse(jsonString);
+  } catch (err) {
+    // eslint-disable-line no-empty
+  }
+
+  // Give up if we don't have valid start, to avoid some unnecessary overhead.
+  first = firstNonWs(jsonString);
+  if (first !== "[" && first !== "{" && isNaN(first) && first !== '"') {
+    return null;
+  }
+
+  // Remove JavaScript comments, quote non-quoted identifiers, and merge
+  // multi-line structures like |{"a": 1} \n {"b": 2}| into a single JSON
+  // object [{"a": 1}, {"b": 2}].
+  jsonString = pseudoJsonToJson(jsonString);
+
+  try {
+    return JSON.parse(jsonString);
+  } catch (err) {
+    // eslint-disable-line no-empty
+  }
+
+  return null;
+};
+
+function firstNonWs(str) {
+  for (let i = 0, len = str.length; i < len; i++) {
+    let ch = str[i];
+    if (ch !== " " && ch !== "\n" && ch !== "\t" && ch !== "\r") {
+      return ch;
+    }
+  }
+  return "";
+}
+
+function pseudoJsonToJson(json) {
+  let ret = "";
+  let at = 0, lasti = 0, lastch = "", hasMultipleParts = false;
+  for (let i = 0, len = json.length; i < len; ++i) {
+    let ch = json[i];
+    if (/\s/.test(ch)) {
+      continue;
+    }
+
+    if (ch === '"') {
+      // Consume a string.
+      ++i;
+      while (i < len) {
+        if (json[i] === "\\") {
+          ++i;
+        } else if (json[i] === '"') {
+          break;
+        }
+        ++i;
+      }
+    } else if (ch === "'") {
+      // Convert an invalid string into a valid one.
+      ret += json.slice(at, i) + "\"";
+      at = i + 1;
+      ++i;
+
+      while (i < len) {
+        if (json[i] === "\\") {
+          ++i;
+        } else if (json[i] === "'") {
+          break;
+        }
+        ++i;
+      }
+
+      if (i < len) {
+        ret += json.slice(at, i) + "\"";
+        at = i + 1;
+      }
+    } else if ((ch === "[" || ch === "{") &&
+        (lastch === "]" || lastch === "}")) {
+      // Multiple JSON messages in one... Make it into a single array by
+      // inserting a comma and setting the "multiple parts" flag.
+      ret += json.slice(at, i) + ",";
+      hasMultipleParts = true;
+      at = i;
+    } else if (lastch === "," && (ch === "]" || ch === "}")) {
+      // Trailing commas in arrays/objects.
+      ret += json.slice(at, lasti);
+      at = i;
+    } else if (lastch === "/" && lasti === i - 1) {
+      // Some kind of comment; remove it.
+      if (ch === "/") {
+        ret += json.slice(at, i - 1);
+        at = i + json.slice(i).search(/\n|\r|$/);
+        i = at - 1;
+      } else if (ch === "*") {
+        ret += json.slice(at, i - 1);
+        at = json.indexOf("*/", i + 1) + 2;
+        if (at === 1) {
+          at = len;
+        }
+        i = at - 1;
+      }
+      ch = "\0";
+    } else if (/[a-zA-Z$_]/.test(ch) && lastch !== ":") {
+      // Non-quoted identifier. Quote it.
+      ret += json.slice(at, i) + "\"";
+      at = i;
+      i = i + json.slice(i).search(/[^a-zA-Z0-9$_]|$/);
+      ret += json.slice(at, i) + "\"";
+      at = i;
+    }
+
+    lastch = ch;
+    lasti = i;
+  }
+
+  ret += json.slice(at);
+  if (hasMultipleParts) {
+    ret = "[" + ret + "]";
+  }
+
+  return ret;
+}
+
+Json.isJSON = function (contentType, data) {
+  // Workaround for JSON responses without proper content type
+  // Let's consider all responses starting with "{" as JSON. In the worst
+  // case there will be an exception when parsing. This means that no-JSON
+  // responses (and post data) (with "{") can be parsed unnecessarily,
+  // which represents a little overhead, but this happens only if the request
+  // is actually expanded by the user in the UI (Net & Console panels).
+  // Do a manual string search instead of checking (data.strip()[0] === "{")
+  // to improve performance/memory usage.
+  let len = data ? data.length : 0;
+  for (let i = 0; i < len; i++) {
+    let ch = data.charAt(i);
+    if (ch === "{") {
+      return true;
+    }
+
+    if (ch === " " || ch === "\t" || ch === "\n" || ch === "\r") {
+      continue;
+    }
+
+    break;
+  }
+
+  if (!contentType) {
+    return false;
+  }
+
+  contentType = contentType.split(";")[0];
+  contentType = contentType.trim();
+  return !!contentTypes[contentType];
+};
+
+// Exports from this module
+module.exports = Json;
+