1 files changed, 97 insertions, 0 deletions
diff --git a/devtools/client/framework/test/browser_source_map-pub-sub.js b/devtools/client/framework/test/browser_source_map-pub-sub.js
new file mode 100644
index 0000000000..c7f69c91c7
--- /dev/null
+++ b/devtools/client/framework/test/browser_source_map-pub-sub.js
@@ -0,0 +1,97 @@
+/* Any copyright is dedicated to the Public Domain.
+ http://creativecommons.org/publicdomain/zero/1.0/ */
+
+// Test that the source map service subscribe mechanism work as expected.
+
+"use strict";
+
+const JS_URL = URL_ROOT + "code_bundle_no_race.js";
+
+const PAGE_URL = `data:text/html,
+<!doctype html>
+<html>
+  <head>
+    <meta charset="utf-8"/>
+  </head>
+  <body>
+    <script src="${JS_URL}"></script>
+  </body>
+</html>`;
+
+const ORIGINAL_URL = "webpack:///code_no_race.js";
+
+const SOURCE_MAP_PREF = "devtools.source-map.client-service.enabled";
+
+const GENERATED_LINE = 84;
+const ORIGINAL_LINE = 11;
+
+add_task(async function () {
+  // Push a pref env so any changes will be reset at the end of the test.
+  await SpecialPowers.pushPrefEnv({});
+
+  // Opening the debugger causes the source actors to be created.
+  const toolbox = await openNewTabAndToolbox(PAGE_URL, "jsdebugger");
+  const service = toolbox.sourceMapURLService;
+
+  const cbCalls = [];
+  const cb = originalLocation => cbCalls.push(originalLocation);
+  const expectedArg = { url: ORIGINAL_URL, line: ORIGINAL_LINE, column: 0 };
+
+  // Wait for the sources to fully populate so that waitForSubscriptionsToSettle
+  // can be guaranteed that all actions have been queued.
+  await service._ensureAllSourcesPopulated();
+
+  const unsubscribe1 = service.subscribeByURL(JS_URL, GENERATED_LINE, 1, cb);
+
+  // Wait for the query to finish and populate so that all of the later
+  // logic with this position will run synchronously, and the subscribe has run.
+  for (const map of service._mapsById.values()) {
+    for (const query of map.queries.values()) {
+      await query.action;
+    }
+  }
+
+  is(
+    cbCalls.length,
+    1,
+    "The callback function is called directly when subscribing"
+  );
+  Assert.deepEqual(
+    cbCalls[0],
+    expectedArg,
+    "callback called with expected arguments"
+  );
+
+  const unsubscribe2 = service.subscribeByURL(JS_URL, GENERATED_LINE, 1, cb);
+  is(cbCalls.length, 2, "Subscribing to the same location twice works");
+  Assert.deepEqual(
+    cbCalls[1],
+    expectedArg,
+    "callback called with expected arguments"
+  );
+
+  info("Manually call the dispatcher to ensure subscribers are called");
+  Services.prefs.setBoolPref(SOURCE_MAP_PREF, false);
+  is(cbCalls.length, 4, "both subscribers were called");
+  Assert.deepEqual(cbCalls[2], null, "callback called with expected arguments");
+  Assert.deepEqual(
+    cbCalls[2],
+    cbCalls[3],
+    "callbacks were passed the same arguments"
+  );
+
+  info("Check unsubscribe functions");
+  unsubscribe1();
+  Services.prefs.setBoolPref(SOURCE_MAP_PREF, true);
+  is(cbCalls.length, 5, "Only remainer subscriber callback was called");
+  Assert.deepEqual(
+    cbCalls[4],
+    expectedArg,
+    "callback called with expected arguments"
+  );
+
+  unsubscribe2();
+  Services.prefs.setBoolPref(SOURCE_MAP_PREF, false);
+  Services.prefs.setBoolPref(SOURCE_MAP_PREF, true);
+  is(cbCalls.length, 5, "No callbacks were called");
+});