1 files changed, 86 insertions, 0 deletions
diff --git a/devtools/server/tests/xpcshell/test_nesting-04.js b/devtools/server/tests/xpcshell/test_nesting-04.js
new file mode 100644
index 0000000000..dcee257c40
--- /dev/null
+++ b/devtools/server/tests/xpcshell/test_nesting-04.js
@@ -0,0 +1,86 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+/**
+ * Verify that we never pause while being already paused.
+ * i.e. we don't support more than one nested event loops.
+ */
+
+add_task(
+  threadFrontTest(async ({ commands, threadFront, debuggee }) => {
+    await threadFront.setBreakpoint({ sourceUrl: "nesting-04.js", line: 2 });
+
+    const packet = await executeOnNextTickAndWaitForPause(
+      () => evalCode(debuggee),
+      threadFront
+    );
+
+    Assert.equal(packet.frame.where.line, 5);
+    Assert.equal(packet.why.type, "debuggerStatement");
+
+    info("Test calling interrupt");
+    const onPaused = waitForPause(threadFront);
+    await threadFront.interrupt();
+    // interrupt() doesn't return anything, but bailout while emitting a paused packet
+    // But we don't pause again, the reason prove it so
+    const paused = await onPaused;
+    equal(paused.why.type, "alreadyPaused");
+
+    info("Test by evaluating code via the console");
+    const { result } = await commands.scriptCommand.execute(
+      "debugger; functionWithDebuggerStatement()",
+      {
+        frameActor: packet.frame.actorID,
+      }
+    );
+    // The fact that it returned immediately means that we did not pause
+    equal(result, 42);
+
+    info("Test by calling code from chrome context");
+    // This should be equivalent to any actor somehow triggering some page's JS
+    const rv = debuggee.functionWithDebuggerStatement();
+    // The fact that it returned immediately means that we did not pause
+    equal(rv, 42);
+
+    info("Test by stepping over a function that breaks");
+    // This will only step over the debugger; statement we just break on
+    const step1 = await stepOver(threadFront);
+    equal(step1.why.type, "resumeLimit");
+    equal(step1.frame.where.line, 6);
+
+    // stepOver will actually resume and re-pause on the breakpoint
+    const step2 = await stepOver(threadFront);
+    equal(step2.why.type, "breakpoint");
+    equal(step2.frame.where.line, 2);
+
+    // Sanity check to ensure that the functionWithDebuggerStatement really pauses
+    info("Resume and pause on the breakpoint");
+    const pausedPacket = await resumeAndWaitForPause(threadFront);
+    Assert.equal(pausedPacket.frame.where.line, 2);
+    // The breakpoint takes over the debugger statement
+    Assert.equal(pausedPacket.why.type, "breakpoint");
+
+    await threadFront.resume();
+  })
+);
+
+function evalCode(debuggee) {
+  /* eslint-disable */
+  Cu.evalInSandbox(
+    `function functionWithDebuggerStatement() {
+      debugger;
+      return 42;
+    }
+    debugger;
+    functionWithDebuggerStatement();
+    var a = 1;
+    functionWithDebuggerStatement();`,
+    debuggee,
+    "1.8",
+    "nesting-04.js",
+    1
+  );
+  /* eslint-enable */
+}