1 files changed, 40 insertions, 0 deletions
diff --git a/devtools/client/debugger/test/mochitest/browser_dbg-step-in-navigate.js b/devtools/client/debugger/test/mochitest/browser_dbg-step-in-navigate.js
new file mode 100644
index 0000000000..bbd9ccd2a2
--- /dev/null
+++ b/devtools/client/debugger/test/mochitest/browser_dbg-step-in-navigate.js
@@ -0,0 +1,40 @@
+/* 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/>. */
+
+// Tests that Step In is cancelled when navigating to another page
+
+add_task(async function() {
+    const dbg = await initDebugger("doc-scripts.html", "simple3.js", "long.js");
+    const {
+      selectors: { getIsWaitingOnBreak, getCurrentThread }
+    } = dbg;
+
+    async function toggleBlackbox() {
+      await selectSource(dbg, "simple3.js");
+      await clickElement(dbg, "blackbox");
+      await waitForDispatch(dbg, "BLACKBOX");
+    }
+
+    // With the debugger stopped at a breakpoint, blackbox the current source and step in
+    await selectSource(dbg, "simple3.js");
+    await addBreakpoint(dbg, "simple3.js", 5);
+    invokeInTab("simple");
+    await waitForPaused(dbg, "simple3");
+
+    await toggleBlackbox();
+    await dbg.actions.stepIn(getThreadContext(dbg));
+
+    // We should stop at this breakpoint, rather than the first executed script
+    await selectSource(dbg, "long.js");
+    await addBreakpoint(dbg, "long.js", 1);
+
+    // Navigation should clear the stepping state
+    const reloaded = reload(dbg);
+    await waitForPaused(dbg);
+    assertPausedAtSourceAndLine(dbg, findSource(dbg, "long.js").id, 1);
+
+    await resume(dbg);
+    await waitForSource(dbg, "simple3.js");
+    await toggleBlackbox();
+  });