1 files changed, 50 insertions, 0 deletions
diff --git a/devtools/client/debugger/test/mochitest/browser_dbg-editor-highlight.js b/devtools/client/debugger/test/mochitest/browser_dbg-editor-highlight.js
new file mode 100644
index 0000000000..4fd5a6be40
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+++ b/devtools/client/debugger/test/mochitest/browser_dbg-editor-highlight.js
@@ -0,0 +1,50 @@
+/* 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 the editor will always highight the right line, no
+// matter if the source text doesn't exist yet or even if the source
+// doesn't exist.
+
+"use strict";
+
+add_task(async function () {
+  const dbg = await initDebugger("doc-scripts.html", "long.js");
+  const {
+    selectors: { getSettledSourceTextContent },
+  } = dbg;
+
+  // The source itself doesn't even exist yet, and using
+  // `selectSourceURL` will set a pending request to load this source
+  // and highlight a specific line.
+
+  await selectSource(dbg, "long.js", 66);
+
+  // TODO: revisit highlighting lines when the debugger opens
+  // assertHighlightLocation(dbg, "long.js", 66);
+
+  info("Select line 16 and make sure the editor scrolled.");
+  await selectSource(dbg, "long.js", 16);
+  await waitForElementWithSelector(dbg, ".CodeMirror-code > .highlight-line");
+  assertHighlightLocation(dbg, "long.js", 16);
+
+  info("Select several locations and check that we have one highlight");
+  await selectSource(dbg, "long.js", 17);
+  await selectSource(dbg, "long.js", 18);
+  assertHighlightLocation(dbg, "long.js", 18);
+
+  // Test jumping to a line in a source that exists but hasn't been
+  // loaded yet.
+  info("Select an unloaded source");
+  selectSource(dbg, "simple1.js", 6);
+
+  // Make sure the source is in the loading state, wait for it to be
+  // fully loaded, and check the highlighted line.
+  const simple1 = findSource(dbg, "simple1.js");
+  const location = createLocation({ source: simple1 });
+  is(getSettledSourceTextContent(location), null);
+
+  await waitForSelectedSource(dbg, "simple1.js");
+  ok(getSettledSourceTextContent(location).value.value);
+  assertHighlightLocation(dbg, "simple1.js", 6);
+});