1 files changed, 32 insertions, 0 deletions
diff --git a/devtools/client/debugger/src/utils/evaluation-result.js b/devtools/client/debugger/src/utils/evaluation-result.js
new file mode 100644
index 0000000000..8f2a59cd22
--- /dev/null
+++ b/devtools/client/debugger/src/utils/evaluation-result.js
@@ -0,0 +1,32 @@
+/* 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 type {
+  Grip,
+  ObjectFront,
+  LongStringFront,
+  ExpressionResult,
+} from "../client/firefox/types";
+
+function isFront(result: ExpressionResult): boolean %checks {
+  return !!result && typeof result === "object" && !!result.getGrip;
+}
+
+export function getGrip(
+  result: ExpressionResult
+): Grip | string | number | null {
+  if (isFront(result)) {
+    return result.getGrip();
+  }
+
+  return result;
+}
+
+export function getFront(
+  result: ExpressionResult
+): ObjectFront | LongStringFront | null {
+  return isFront(result) ? result : null;
+}