1 files changed, 26 insertions, 0 deletions
diff --git a/devtools/client/debugger/src/selectors/isLineInScope.js b/devtools/client/debugger/src/selectors/isLineInScope.js
new file mode 100644
index 0000000000..fec2fe07e2
--- /dev/null
+++ b/devtools/client/debugger/src/selectors/isLineInScope.js
@@ -0,0 +1,26 @@
+/* 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/>. */
+
+// @flow
+
+import { getInScopeLines } from "../reducers/ast";
+import { getVisibleSelectedFrame } from "./pause";
+
+import type { State } from "../reducers/types";
+
+// Checks if a line is considered in scope
+// We consider all lines in scope, if we do not have lines in scope.
+export function isLineInScope(state: State, line: number): boolean {
+  const frame = getVisibleSelectedFrame(state);
+  if (!frame) {
+    return false;
+  }
+
+  const lines = getInScopeLines(state, frame.location);
+  if (!lines) {
+    return true;
+  }
+
+  return lines.includes(line);
+}