1 files changed, 31 insertions, 0 deletions
diff --git a/js/src/jit-test/tests/debug/Debugger-findScripts-optimized-out.js b/js/src/jit-test/tests/debug/Debugger-findScripts-optimized-out.js
new file mode 100644
index 0000000000..1c38bbbf4e
--- /dev/null
+++ b/js/src/jit-test/tests/debug/Debugger-findScripts-optimized-out.js
@@ -0,0 +1,31 @@
+// Accessing Debugger.Script's properties which triggers delazification can
+// fail if the function for the script is optimized out.
+// It shouldn't crash but just throw an error.
+
+load(libdir + "asserts.js");
+
+var g = newGlobal({newCompartment: true});
+var dbg = new Debugger(g);
+g.eval(`
+function enclosing() {
+    (function g1() {});
+    (function* g2() {});
+    (async function g3() {});
+    (async function* g4() {});
+    () => {};
+    async () => {};
+}
+`);
+
+for (const s of dbg.findScripts()) {
+    if (!s.displayName) {
+        continue;
+    }
+
+    try {
+        s.lineCount;  // don't assert
+    } catch (exc) {
+        // If that didn't throw, it's fine. If it did, check the message.
+        assertEq(exc.message, "function is optimized out");
+    }
+}