Bug 1576085 - Don't allow evaluation results to be repeated. r=Honza.

With top-level await, we can now have multiple
evaluation results next to each others. Which
means that if they had the same repeatId, we
would only print the first result.
We fix that by not allowing evaluation results to
be repeated.
A mochitest is added to ensure the patch properly
fixes the issue.

Differential Revision: https://phabricator.services.mozilla.com/D43253

--HG--
extra : moz-landing-system : lando

devtools/client/webconsole/test/browser/browser.ini

@@ -207,6 +207,7 @@ skip-if = verify
 [browser_jsterm_autocomplete_will_navigate.js]
 [browser_jsterm_autocomplete-properties-with-non-alphanumeric-names.js]
 [browser_jsterm_await_assignments.js]
+[browser_jsterm_await_concurrent_same_result.js]
 [browser_jsterm_await_concurrent.js]
 [browser_jsterm_await_dynamic_import.js]
 [browser_jsterm_await_error.js]

devtools/client/webconsole/test/browser/browser_jsterm_await_concurrent_same_result.js

@@ -0,0 +1,41 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+// Test that hitting Ctrl + E does toggle the editor mode.
+// See https://bugzilla.mozilla.org/show_bug.cgi?id=1519105
+
+"use strict";
+
+const TEST_URI =
+  "data:text/html;charset=utf-8,Test concurrent top-level await expressions returning same value";
+
+add_task(async function() {
+  // Enable editor mode as we'll be able to quicly trigger multiple evaluations.
+  await pushPref("devtools.webconsole.features.editor", true);
+  await pushPref("devtools.webconsole.input.editor", true);
+
+  const hud = await openNewTabAndConsole(TEST_URI);
+  setInputValue(
+    hud,
+    `await new Promise(res => setTimeout(() => res("foo"), 5000))`
+  );
+
+  info("Evaluate the expression 3 times in a row");
+  const executeButton = hud.ui.outputNode.querySelector(
+    ".webconsole-editor-toolbar-executeButton"
+  );
+
+  executeButton.click();
+  executeButton.click();
+  executeButton.click();
+
+  await waitFor(
+    () => findMessages(hud, "foo", ".result").length === 3,
+    "Waiting for all results to be printed in console",
+    1000
+  );
+  ok(true, "There are as many results as commands");
+
+  Services.prefs.clearUserPref("devtools.webconsole.features.editor");
+  Services.prefs.clearUserPref("devtools.webconsole.input.editor");
+});

devtools/client/webconsole/utils/messages.js

@@ -405,6 +405,7 @@ function transformEvaluationResultPacket(packet) {
     timeStamp,
     notes,
     private: packet.private,
+    allowRepeating: false,
   });
 }