1 files changed, 103 insertions, 0 deletions
diff --git a/devtools/client/shared/source-map-loader/utils/index.js b/devtools/client/shared/source-map-loader/utils/index.js
new file mode 100644
index 0000000000..1bcfcfac7d
--- /dev/null
+++ b/devtools/client/shared/source-map-loader/utils/index.js
@@ -0,0 +1,103 @@
+/* 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";
+
+const md5 = require("resource://devtools/client/shared/vendor/md5.js");
+
+function originalToGeneratedId(sourceId) {
+  if (isGeneratedId(sourceId)) {
+    return sourceId;
+  }
+
+  const lastIndex = sourceId.lastIndexOf("/originalSource");
+
+  return lastIndex !== -1 ? sourceId.slice(0, lastIndex) : "";
+}
+
+const getMd5 = memoize(url => md5(url));
+
+function generatedToOriginalId(generatedId, url) {
+  return `${generatedId}/originalSource-${getMd5(url)}`;
+}
+
+function isOriginalId(id) {
+  return id.includes("/originalSource");
+}
+
+function isGeneratedId(id) {
+  return !isOriginalId(id);
+}
+
+/**
+ * Trims the query part or reference identifier of a URL string, if necessary.
+ */
+function trimUrlQuery(url) {
+  const length = url.length;
+
+  for (let i = 0; i < length; ++i) {
+    if (url[i] === "?" || url[i] === "&" || url[i] === "#") {
+      return url.slice(0, i);
+    }
+  }
+
+  return url;
+}
+
+// Map suffix to content type.
+const contentMap = {
+  js: "text/javascript",
+  jsm: "text/javascript",
+  mjs: "text/javascript",
+  ts: "text/typescript",
+  tsx: "text/typescript-jsx",
+  jsx: "text/jsx",
+  vue: "text/vue",
+  coffee: "text/coffeescript",
+  elm: "text/elm",
+  cljc: "text/x-clojure",
+  cljs: "text/x-clojurescript",
+};
+
+/**
+ * Returns the content type for the specified URL.  If no specific
+ * content type can be determined, "text/plain" is returned.
+ *
+ * @return String
+ *         The content type.
+ */
+function getContentType(url) {
+  url = trimUrlQuery(url);
+  const dot = url.lastIndexOf(".");
+  if (dot >= 0) {
+    const name = url.substring(dot + 1);
+    if (name in contentMap) {
+      return contentMap[name];
+    }
+  }
+  return "text/plain";
+}
+
+function memoize(func) {
+  const map = new Map();
+
+  return arg => {
+    if (map.has(arg)) {
+      return map.get(arg);
+    }
+
+    const result = func(arg);
+    map.set(arg, result);
+    return result;
+  };
+}
+
+module.exports = {
+  originalToGeneratedId,
+  generatedToOriginalId,
+  isOriginalId,
+  isGeneratedId,
+  getContentType,
+  contentMapForTesting: contentMap,
+};