1 files changed, 59 insertions, 0 deletions
diff --git a/toolkit/modules/tests/xpcshell/test_Log_nsIStackFrame.js b/toolkit/modules/tests/xpcshell/test_Log_nsIStackFrame.js
new file mode 100644
index 0000000000..b7fdd511e1
--- /dev/null
+++ b/toolkit/modules/tests/xpcshell/test_Log_nsIStackFrame.js
@@ -0,0 +1,59 @@
+const { Log } = ChromeUtils.importESModule(
+  "resource://gre/modules/Log.sys.mjs"
+);
+
+function foo() {
+  return bar(); // line 6
+}
+
+function bar() {
+  return baz(); // line 10
+}
+
+function baz() {
+  return Log.stackTrace(Components.stack.caller); // line 14
+}
+
+function start() {
+  return next(); // line 18
+}
+
+function next() {
+  return finish(); // line 22
+}
+
+function finish() {
+  return Log.stackTrace(); // line 26
+}
+
+function run_test() {
+  const stackFrameTrace = foo(); // line 30
+
+  print(`Got trace for nsIStackFrame case: ${stackFrameTrace}`);
+
+  const fooPos = stackFrameTrace.search(/foo@.*test_Log_nsIStackFrame.js:6/);
+  const barPos = stackFrameTrace.search(/bar@.*test_Log_nsIStackFrame.js:10/);
+  const runTestPos = stackFrameTrace.search(
+    /run_test@.*test_Log_nsIStackFrame.js:30/
+  );
+
+  print(`String positions: ${runTestPos} ${barPos} ${fooPos}`);
+  Assert.ok(barPos >= 0);
+  Assert.ok(fooPos > barPos);
+  Assert.ok(runTestPos > fooPos);
+
+  const emptyArgTrace = start();
+
+  print(`Got trace for empty argument case: ${emptyArgTrace}`);
+
+  const startPos = emptyArgTrace.search(/start@.*test_Log_nsIStackFrame.js:18/);
+  const nextPos = emptyArgTrace.search(/next@.*test_Log_nsIStackFrame.js:22/);
+  const finishPos = emptyArgTrace.search(
+    /finish@.*test_Log_nsIStackFrame.js:26/
+  );
+
+  print(`String positions: ${finishPos} ${nextPos} ${startPos}`);
+  Assert.ok(finishPos >= 0);
+  Assert.ok(nextPos > finishPos);
+  Assert.ok(startPos > nextPos);
+}