1 files changed, 39 insertions, 0 deletions
diff --git a/toolkit/modules/tests/xpcshell/test_Log_stackTrace.js b/toolkit/modules/tests/xpcshell/test_Log_stackTrace.js
new file mode 100644
index 0000000000..973cb9350b
--- /dev/null
+++ b/toolkit/modules/tests/xpcshell/test_Log_stackTrace.js
@@ -0,0 +1,39 @@
+print("Define some functions in well defined line positions for the test");
+function foo(v) {
+  return bar(v + 1);
+} // line 3
+function bar(v) {
+  return baz(v + 1);
+} // line 6
+function baz(v) {
+  throw new Error(v + 1);
+} // line 9
+
+print("Make sure lazy constructor calling/assignment works");
+const { Log } = ChromeUtils.importESModule(
+  "resource://gre/modules/Log.sys.mjs"
+);
+
+function run_test() {
+  print(
+    "Make sure functions, arguments, files are pretty printed in the trace"
+  );
+  let trace = "";
+  try {
+    foo(0);
+  } catch (ex) {
+    trace = Log.stackTrace(ex);
+  }
+  print(`Got trace: ${trace}`);
+  Assert.notEqual(trace, "");
+
+  let bazPos = trace.indexOf("baz@test_Log_stackTrace.js:9");
+  let barPos = trace.indexOf("bar@test_Log_stackTrace.js:6");
+  let fooPos = trace.indexOf("foo@test_Log_stackTrace.js:3");
+  print(`String positions: ${bazPos} ${barPos} ${fooPos}`);
+
+  print("Make sure the desired messages show up");
+  Assert.ok(bazPos >= 0);
+  Assert.ok(barPos > bazPos);
+  Assert.ok(fooPos > barPos);
+}