1 files changed, 74 insertions, 0 deletions
diff --git a/devtools/server/tests/xpcshell/test_breakpoint-03.js b/devtools/server/tests/xpcshell/test_breakpoint-03.js
new file mode 100644
index 0000000000..f598660a98
--- /dev/null
+++ b/devtools/server/tests/xpcshell/test_breakpoint-03.js
@@ -0,0 +1,74 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+/* eslint-disable no-shadow, max-nested-callbacks */
+
+"use strict";
+
+/**
+ * Check that setting a breakpoint on a line without code will skip
+ * forward when we know the script isn't GCed (the debugger is connected,
+ * so it's kept alive).
+ */
+
+var test_no_skip_breakpoint = async function (source, location, debuggee) {
+  const [response, bpClient] = await source.setBreakpoint(
+    Object.assign({}, location, { noSliding: true })
+  );
+
+  Assert.ok(!response.actualLocation);
+  Assert.equal(bpClient.location.line, debuggee.line0 + 3);
+  await bpClient.remove();
+};
+
+add_task(
+  threadFrontTest(({ threadFront, debuggee }) => {
+    return new Promise(resolve => {
+      threadFront.once("paused", async function (packet) {
+        const location = { line: debuggee.line0 + 3 };
+        const source = await getSourceById(
+          threadFront,
+          packet.frame.where.actor
+        );
+        // First, make sure that we can disable sliding with the
+        // `noSliding` option.
+        await test_no_skip_breakpoint(source, location, debuggee);
+
+        // Now make sure that the breakpoint properly slides forward one line.
+        const [response, bpClient] = await source.setBreakpoint(location);
+        Assert.ok(!!response.actualLocation);
+        Assert.equal(response.actualLocation.source.actor, source.actor);
+        Assert.equal(response.actualLocation.line, location.line + 1);
+
+        threadFront.once("paused", function (packet) {
+          // Check the return value.
+          Assert.equal(packet.frame.where.actor, source.actor);
+          Assert.equal(packet.frame.where.line, location.line + 1);
+          Assert.equal(packet.why.type, "breakpoint");
+          Assert.equal(packet.why.actors[0], bpClient.actor);
+          // Check that the breakpoint worked.
+          Assert.equal(debuggee.a, 1);
+          Assert.equal(debuggee.b, undefined);
+
+          // Remove the breakpoint.
+          bpClient.remove(function (response) {
+            threadFront.resume().then(resolve);
+          });
+        });
+
+        threadFront.resume();
+      });
+
+      // Use `evalInSandbox` to make the debugger treat it as normal
+      // globally-scoped code, where breakpoint sliding rules apply.
+      // prettier-ignore
+      Cu.evalInSandbox(
+        "var line0 = Error().lineNumber;\n" +
+        "debugger;\n" +      // line0 + 1
+        "var a = 1;\n" +     // line0 + 2
+        "// A comment.\n" +  // line0 + 3
+        "var b = 2;",        // line0 + 4
+        debuggee
+      );
+    });
+  })
+);