1 files changed, 122 insertions, 0 deletions
diff --git a/devtools/client/debugger/src/utils/source-maps.js b/devtools/client/debugger/src/utils/source-maps.js
new file mode 100644
index 0000000000..774bb3997f
--- /dev/null
+++ b/devtools/client/debugger/src/utils/source-maps.js
@@ -0,0 +1,122 @@
+/* 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/>. */
+
+import { isOriginalId } from "devtools/client/shared/source-map-loader/index";
+import {
+  debuggerToSourceMapLocation,
+  sourceMapToDebuggerLocation,
+} from "./location";
+import { waitForSourceToBeRegisteredInStore } from "../client/firefox/create";
+
+/**
+ * For any location, return the matching generated location.
+ * If this is already a generated location, returns the same location.
+ *
+ * In additional to `SourceMapLoader.getGeneratedLocation`,
+ * this asserts that the related source is still registered in the reducer current state.
+ *
+ * @param {Object} location
+ * @param {Object} thunkArgs
+ *        Redux action thunk arguments
+ * @param {Object}
+ *        The matching generated location.
+ */
+export async function getGeneratedLocation(location, thunkArgs) {
+  if (!isOriginalId(location.sourceId)) {
+    return location;
+  }
+
+  const { sourceMapLoader, getState } = thunkArgs;
+  const generatedLocation = await sourceMapLoader.getGeneratedLocation(
+    debuggerToSourceMapLocation(location)
+  );
+  if (!generatedLocation) {
+    return location;
+  }
+
+  return sourceMapToDebuggerLocation(getState(), generatedLocation);
+}
+
+/**
+ * For any location, return the matching original location.
+ * If this is already an original location, returns the same location.
+ *
+ * In additional to `SourceMapLoader.getOriginalLocation`,
+ * this automatically fetches the original source object in order to build
+ * the original location object.
+ *
+ * @param {Object} location
+ * @param {Object} thunkArgs
+ *        Redux action thunk arguments
+ * @param {boolean} waitForSource
+ *        Default to false. If true is passed, this function will
+ *        ensure waiting, possibly asynchronously for the related original source
+ *        to be registered in the redux store.
+ *
+ * @param {Object}
+ *        The matching original location.
+ */
+export async function getOriginalLocation(
+  location,
+  thunkArgs,
+  waitForSource = false
+) {
+  if (isOriginalId(location.sourceId)) {
+    return location;
+  }
+  const { getState, sourceMapLoader } = thunkArgs;
+  const originalLocation = await sourceMapLoader.getOriginalLocation(
+    debuggerToSourceMapLocation(location)
+  );
+  if (!originalLocation) {
+    return location;
+  }
+
+  // When we are mapping frames while being paused,
+  // the original source may not be registered yet in the reducer.
+  if (waitForSource) {
+    await waitForSourceToBeRegisteredInStore(originalLocation.sourceId);
+  }
+
+  return sourceMapToDebuggerLocation(getState(), originalLocation);
+}
+
+export async function getMappedLocation(location, thunkArgs) {
+  if (!location.source) {
+    throw new Error(`no source ${location.sourceId}`);
+  }
+
+  if (isOriginalId(location.sourceId)) {
+    const generatedLocation = await getGeneratedLocation(location, thunkArgs);
+    return { location, generatedLocation };
+  }
+
+  const generatedLocation = location;
+  const originalLocation = await getOriginalLocation(
+    generatedLocation,
+    thunkArgs
+  );
+
+  return { location: originalLocation, generatedLocation };
+}
+
+/**
+ * Gets the "mapped location".
+ *
+ * If the passed location is on a generated source, it gets the
+ * related location in the original source.
+ * If the passed location is on an original source, it gets the
+ * related location in the generated source.
+ */
+export async function getRelatedMapLocation(location, thunkArgs) {
+  if (!location.source) {
+    return location;
+  }
+
+  if (isOriginalId(location.sourceId)) {
+    return getGeneratedLocation(location, thunkArgs);
+  }
+
+  return getOriginalLocation(location, thunkArgs);
+}