1 files changed, 40 insertions, 0 deletions
diff --git a/devtools/client/debugger/src/selectors/isSelectedFrameVisible.js b/devtools/client/debugger/src/selectors/isSelectedFrameVisible.js
new file mode 100644
index 0000000000..bd0dc7a456
--- /dev/null
+++ b/devtools/client/debugger/src/selectors/isSelectedFrameVisible.js
@@ -0,0 +1,40 @@
+/* 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 {
+  originalToGeneratedId,
+  isOriginalId,
+} from "devtools/client/shared/source-map-loader/index";
+import { getSelectedFrame, getSelectedLocation, getCurrentThread } from ".";
+
+function getGeneratedId(sourceId) {
+  if (isOriginalId(sourceId)) {
+    return originalToGeneratedId(sourceId);
+  }
+
+  return sourceId;
+}
+
+/*
+ * Checks to if the selected frame's source is currently
+ * selected.
+ */
+export function isSelectedFrameVisible(state) {
+  const thread = getCurrentThread(state);
+  const selectedLocation = getSelectedLocation(state);
+  const selectedFrame = getSelectedFrame(state, thread);
+
+  if (!selectedFrame || !selectedLocation) {
+    return false;
+  }
+
+  if (isOriginalId(selectedLocation.sourceId)) {
+    return selectedLocation.sourceId === selectedFrame.location.sourceId;
+  }
+
+  return (
+    selectedLocation.sourceId ===
+    getGeneratedId(selectedFrame.location.sourceId)
+  );
+}