diff --git a/devtools/client/webconsole/reducers/messages.js b/devtools/client/webconsole/reducers/messages.js
index 2993483c17eb..e7a9525ca2b8 100644
--- a/devtools/client/webconsole/reducers/messages.js
+++ b/devtools/client/webconsole/reducers/messages.js
@@ -151,8 +151,10 @@ function addMessage(newMessage, state, filtersState, prefsState) {
 
   // Add the new message with a reference to the parent group.
   const parentGroups = getParentGroups(currentGroup, groupsById);
-  newMessage.groupId = currentGroup;
-  newMessage.indent = parentGroups.length;
+  if (!isWarningGroup(newMessage)) {
+    newMessage.groupId = currentGroup;
+    newMessage.indent = parentGroups.length;
+  }
 
   ensureExecutionPoint(state, newMessage);
 
@@ -188,12 +190,27 @@ function addMessage(newMessage, state, filtersState, prefsState) {
     ) {
       // Then we put it in the visibleMessages properties, at the position of the first
       // warning message inside the warningGroup.
-      // TODO [Bug 1534927]: It should be added before the outermost console.group message
-      // a warning message could be in.
-      const index = state
-        .visibleMessages
-        .indexOf(state.warningGroupsById.get(warningGroupMessageId)[0]);
-      state.visibleMessages.splice(index, 1, warningGroupMessageId);
+      // If that first warning message is in a console.group, we place it before the
+      // outermost console.group message.
+      const firstWarningMessageId = state.warningGroupsById.get(warningGroupMessageId)[0];
+      const firstWarningMessage = state.messagesById.get(firstWarningMessageId);
+      const outermostGroupId = getOutermostGroup(firstWarningMessage, groupsById);
+      const groupIndex = state.visibleMessages.indexOf(outermostGroupId);
+      const warningMessageIndex = state.visibleMessages.indexOf(firstWarningMessageId);
+
+      if (groupIndex > -1) {
+        // We remove the warning message
+        if (warningMessageIndex > -1) {
+          state.visibleMessages.splice(warningMessageIndex, 1);
+        }
+
+        // And we put the warning group before the console.group
+        state.visibleMessages.splice(groupIndex, 0, warningGroupMessageId);
+      } else {
+        // If the warning message is not in a console.group, we replace it by the
+        // warning group message.
+        state.visibleMessages.splice(warningMessageIndex, 1, warningGroupMessageId);
+      }
     }
   }
 
@@ -415,11 +432,20 @@ function messages(state = MessageState(), action, filtersState, prefsState) {
 
       // If the message is a group
       if (isGroupType(messagesById.get(messageId).type)) {
-        // Hide all its children
-        closeState.visibleMessages = visibleMessages.filter(id =>
-          getParentGroups(messagesById.get(id).groupId, groupsById)
-            .includes(messageId) === false
-        );
+        // Hide all its children, unless they're in a warningGroup.
+        closeState.visibleMessages = visibleMessages.filter((id, i, arr) => {
+          const message = messagesById.get(id);
+          const warningGroupMessage =
+            messagesById.get(getParentWarningGroupMessageId(message));
+
+          // If the message is in a warning group, then we return its current visibility.
+          if (shouldGroupWarningMessages(warningGroupMessage, closeState, prefsState)) {
+            return arr.includes(id);
+          }
+
+          const parentGroups = getParentGroups(message.groupId, groupsById);
+          return parentGroups.includes(messageId) === false;
+        });
       } else if (isWarningGroup(messagesById.get(messageId))) {
         // If the message was a warningGroup, we hide all the messages in the group.
         const groupMessages = closeState.warningGroupsById.get(messageId);
@@ -551,6 +577,14 @@ function getParentGroups(currentGroup, groupsById) {
   return groups;
 }
 
+function getOutermostGroup(message, groupsById) {
+  const groups = getParentGroups(message.groupId, groupsById);
+  if (groups.length === 0) {
+    return null;
+  }
+  return groups[groups.length - 1];
+}
+
 /**
  * Remove all top level messages that exceeds message limit.
  * Also populate an array of all backend actors associated with these
@@ -734,10 +768,14 @@ function getMessageVisibility(message, {
     prefsState,
     checkGroup = true,
 }) {
-  // Do not display the message if it's in closed group.
+  const warningGroupMessage =
+    messagesState.messagesById.get(getParentWarningGroupMessageId(message));
+
+  // Do not display the message if it's in closed group and not in a warning group.
   if (
     checkGroup
     && !isInOpenedGroup(message, messagesState.groupsById, messagesState.messagesUiById)
+    && !shouldGroupWarningMessages(warningGroupMessage, messagesState, prefsState)
   ) {
     return {
       visible: false,
@@ -1183,6 +1221,10 @@ function getLastMessageId(state) {
  * @param {PrefsState} prefsState
  */
 function shouldGroupWarningMessages(warningGroupMessage, messagesState, prefsState) {
+  if (!warningGroupMessage) {
+    return false;
+  }
+
   // Only group if the preference is ON.
   if (!prefsState.groupWarnings) {
     return false;
@@ -1190,7 +1232,11 @@ function shouldGroupWarningMessages(warningGroupMessage, messagesState, prefsSta
 
   // We group warning messages if there are at least 2 messages that could go in it.
   const warningGroup = messagesState.warningGroupsById.get(warningGroupMessage.id);
-  return warningGroup && warningGroup.length > 1;
+  if (!warningGroup || !Array.isArray(warningGroup)) {
+    return false;
+  }
+
+  return warningGroup.length > 1;
 }
 
 exports.messages = messages;
diff --git a/devtools/client/webconsole/test/mochitest/browser.ini b/devtools/client/webconsole/test/mochitest/browser.ini
index fe2e6cffc301..bca3774603d1 100644
--- a/devtools/client/webconsole/test/mochitest/browser.ini
+++ b/devtools/client/webconsole/test/mochitest/browser.ini
@@ -399,5 +399,6 @@ tags = trackingprotection
 [browser_webconsole_visibility_messages.js]
 [browser_webconsole_warn_about_replaced_api.js]
 [browser_webconsole_warning_group_content_blocking.js]
+[browser_webconsole_warning_groups_outside_console_group.js]
 [browser_webconsole_warning_groups.js]
 [browser_webconsole_websocket.js]
diff --git a/devtools/client/webconsole/test/mochitest/browser_webconsole_warning_group_content_blocking.js b/devtools/client/webconsole/test/mochitest/browser_webconsole_warning_group_content_blocking.js
index 46d061eea044..9bace1b7193f 100644
--- a/devtools/client/webconsole/test/mochitest/browser_webconsole_warning_group_content_blocking.js
+++ b/devtools/client/webconsole/test/mochitest/browser_webconsole_warning_group_content_blocking.js
@@ -63,7 +63,7 @@ add_task(async function testContentBlockingMessage() {
     "The badge has the expected text");
 
   checkConsoleOutputForWarningGroup(hud, [
-    `▶︎ ${CONTENT_BLOCKING_GROUP_LABEL} 2`,
+    `▶︎⚠ ${CONTENT_BLOCKING_GROUP_LABEL} 2`,
   ]);
 
   info("Open the group");
@@ -71,7 +71,7 @@ add_task(async function testContentBlockingMessage() {
   await waitFor(() => findMessage(hud, "http://tracking.example.com/?1"));
 
   checkConsoleOutputForWarningGroup(hud, [
-    `▼︎ ${CONTENT_BLOCKING_GROUP_LABEL} 2`,
+    `▼︎⚠ ${CONTENT_BLOCKING_GROUP_LABEL} 2`,
     `| The resource at \u201chttp://tracking.example.com/?1&${now}\u201d was blocked`,
     `| The resource at \u201chttp://tracking.example.com/?2&${now}\u201d was blocked`,
   ]);
@@ -154,7 +154,7 @@ async function testStorageAccessBlockedGrouping(getWarningMessage) {
     "The badge has the expected text");
 
   checkConsoleOutputForWarningGroup(hud, [
-    `▶︎ ${CONTENT_BLOCKING_GROUP_LABEL} 2`,
+    `▶︎⚠ ${CONTENT_BLOCKING_GROUP_LABEL} 2`,
   ]);
 
   info("Open the group");
@@ -162,7 +162,7 @@ async function testStorageAccessBlockedGrouping(getWarningMessage) {
   await waitFor(() => findMessage(hud, TRACKER_IMG));
 
   checkConsoleOutputForWarningGroup(hud, [
-    `▼︎ ${CONTENT_BLOCKING_GROUP_LABEL} 2`,
+    `▼︎⚠ ${CONTENT_BLOCKING_GROUP_LABEL} 2`,
     `| ${getWarningMessage(TRACKER_IMG + "?1&" + now)}`,
     `| ${getWarningMessage(TRACKER_IMG + "?2&" + now)}`,
   ]);
diff --git a/devtools/client/webconsole/test/mochitest/browser_webconsole_warning_groups.js b/devtools/client/webconsole/test/mochitest/browser_webconsole_warning_groups.js
index 3879bb26b0b4..9532229d356f 100644
--- a/devtools/client/webconsole/test/mochitest/browser_webconsole_warning_groups.js
+++ b/devtools/client/webconsole/test/mochitest/browser_webconsole_warning_groups.js
@@ -52,7 +52,7 @@ add_task(async function testContentBlockingMessage() {
     "The badge has the expected text");
 
   checkConsoleOutputForWarningGroup(hud, [
-    `▶︎ ${CONTENT_BLOCKING_GROUP_LABEL}`,
+    `▶︎⚠ ${CONTENT_BLOCKING_GROUP_LABEL}`,
     `simple message 1`,
   ]);
 
@@ -60,7 +60,7 @@ add_task(async function testContentBlockingMessage() {
   await logString(hud, "simple message 2");
 
   checkConsoleOutputForWarningGroup(hud, [
-    `▶︎ ${CONTENT_BLOCKING_GROUP_LABEL}`,
+    `▶︎⚠ ${CONTENT_BLOCKING_GROUP_LABEL}`,
     `simple message 1`,
     `simple message 2`,
   ]);
@@ -70,7 +70,7 @@ add_task(async function testContentBlockingMessage() {
   await waitFor(() => node.querySelector(".warning-group-badge").textContent == "3");
 
   checkConsoleOutputForWarningGroup(hud, [
-    `▶︎ ${CONTENT_BLOCKING_GROUP_LABEL}`,
+    `▶︎⚠ ${CONTENT_BLOCKING_GROUP_LABEL}`,
     `simple message 1`,
     `simple message 2`,
   ]);
@@ -80,7 +80,7 @@ add_task(async function testContentBlockingMessage() {
   await waitFor(() => findMessage(hud, BLOCKED_URL));
 
   checkConsoleOutputForWarningGroup(hud, [
-    `▼︎ ${CONTENT_BLOCKING_GROUP_LABEL}`,
+    `▼︎⚠ ${CONTENT_BLOCKING_GROUP_LABEL}`,
     `| ${BLOCKED_URL}?1`,
     `| ${BLOCKED_URL}?2`,
     `| ${BLOCKED_URL}?3`,
@@ -96,7 +96,7 @@ add_task(async function testContentBlockingMessage() {
   ok(true, "The new tracking protection message is displayed");
 
   checkConsoleOutputForWarningGroup(hud, [
-    `▼︎ ${CONTENT_BLOCKING_GROUP_LABEL}`,
+    `▼︎⚠ ${CONTENT_BLOCKING_GROUP_LABEL}`,
     `| ${BLOCKED_URL}?1`,
     `| ${BLOCKED_URL}?2`,
     `| ${BLOCKED_URL}?3`,
@@ -125,7 +125,7 @@ add_task(async function testContentBlockingMessage() {
   await logString(hud, "simple message 3");
 
   checkConsoleOutputForWarningGroup(hud, [
-    `▼︎ ${CONTENT_BLOCKING_GROUP_LABEL}`,
+    `▼︎⚠ ${CONTENT_BLOCKING_GROUP_LABEL}`,
     `| ${BLOCKED_URL}?1`,
     `| ${BLOCKED_URL}?2`,
     `| ${BLOCKED_URL}?3`,
@@ -146,7 +146,7 @@ add_task(async function testContentBlockingMessage() {
     "The badge has the expected text");
 
   checkConsoleOutputForWarningGroup(hud, [
-    `▼︎ ${CONTENT_BLOCKING_GROUP_LABEL}`,
+    `▼︎⚠ ${CONTENT_BLOCKING_GROUP_LABEL}`,
     `| ${BLOCKED_URL}?1`,
     `| ${BLOCKED_URL}?2`,
     `| ${BLOCKED_URL}?3`,
@@ -154,7 +154,7 @@ add_task(async function testContentBlockingMessage() {
     `simple message 1`,
     `simple message 2`,
     `Navigated to`,
-    `▶︎ ${CONTENT_BLOCKING_GROUP_LABEL}`,
+    `▶︎⚠ ${CONTENT_BLOCKING_GROUP_LABEL}`,
     `simple message 3`,
   ]);
 
@@ -163,7 +163,7 @@ add_task(async function testContentBlockingMessage() {
   await waitFor(() => findMessages(hud, BLOCKED_URL).length === 6);
 
   checkConsoleOutputForWarningGroup(hud, [
-    `▼︎ ${CONTENT_BLOCKING_GROUP_LABEL}`,
+    `▼︎⚠ ${CONTENT_BLOCKING_GROUP_LABEL}`,
     `| ${BLOCKED_URL}?1`,
     `| ${BLOCKED_URL}?2`,
     `| ${BLOCKED_URL}?3`,
@@ -171,7 +171,7 @@ add_task(async function testContentBlockingMessage() {
     `simple message 1`,
     `simple message 2`,
     `Navigated to`,
-    `▼︎ ${CONTENT_BLOCKING_GROUP_LABEL}`,
+    `▼︎⚠ ${CONTENT_BLOCKING_GROUP_LABEL}`,
     `| ${BLOCKED_URL}?5`,
     `| ${BLOCKED_URL}?6`,
     `simple message 3`,
@@ -182,7 +182,7 @@ add_task(async function testContentBlockingMessage() {
   await waitFor(() => findMessages(hud, BLOCKED_URL).length === 4);
 
   checkConsoleOutputForWarningGroup(hud, [
-    `▼︎ ${CONTENT_BLOCKING_GROUP_LABEL}`,
+    `▼︎⚠ ${CONTENT_BLOCKING_GROUP_LABEL}`,
     `| ${BLOCKED_URL}?1`,
     `| ${BLOCKED_URL}?2`,
     `| ${BLOCKED_URL}?3`,
@@ -190,7 +190,7 @@ add_task(async function testContentBlockingMessage() {
     `simple message 1`,
     `simple message 2`,
     `Navigated to`,
-    `▶︎ ${CONTENT_BLOCKING_GROUP_LABEL}`,
+    `▶︎⚠ ${CONTENT_BLOCKING_GROUP_LABEL}`,
     `simple message 3`,
   ]);
 
@@ -199,7 +199,7 @@ add_task(async function testContentBlockingMessage() {
   await waitFor(() => node.querySelector(".warning-group-badge").textContent == "3");
 
   checkConsoleOutputForWarningGroup(hud, [
-    `▼︎ ${CONTENT_BLOCKING_GROUP_LABEL}`,
+    `▼︎⚠ ${CONTENT_BLOCKING_GROUP_LABEL}`,
     `| ${BLOCKED_URL}?1`,
     `| ${BLOCKED_URL}?2`,
     `| ${BLOCKED_URL}?3`,
@@ -207,7 +207,7 @@ add_task(async function testContentBlockingMessage() {
     `simple message 1`,
     `simple message 2`,
     `Navigated to`,
-    `▶︎ ${CONTENT_BLOCKING_GROUP_LABEL}`,
+    `▶︎⚠ ${CONTENT_BLOCKING_GROUP_LABEL}`,
     `simple message 3`,
   ]);
 });
diff --git a/devtools/client/webconsole/test/mochitest/browser_webconsole_warning_groups_outside_console_group.js b/devtools/client/webconsole/test/mochitest/browser_webconsole_warning_groups_outside_console_group.js
new file mode 100644
index 000000000000..7dbdf874b1d3
--- /dev/null
+++ b/devtools/client/webconsole/test/mochitest/browser_webconsole_warning_groups_outside_console_group.js
@@ -0,0 +1,201 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+// Test that warning groups are not created outside console.group.
+
+"use strict";
+requestLongerTimeout(2);
+
+const TEST_FILE =
+  "browser/devtools/client/webconsole/test/mochitest/test-warning-groups.html";
+const TEST_URI = "http://example.com/" + TEST_FILE;
+
+const TRACKER_URL = "http://tracking.example.org/";
+const BLOCKED_URL = TRACKER_URL +
+  "browser/devtools/client/webconsole/test/mochitest/test-image.png";
+
+const {UrlClassifierTestUtils} = ChromeUtils.import("resource://testing-common/UrlClassifierTestUtils.jsm");
+UrlClassifierTestUtils.addTestTrackers();
+registerCleanupFunction(function() {
+  UrlClassifierTestUtils.cleanupTestTrackers();
+});
+
+// Tracking protection preferences
+pushPref("privacy.trackingprotection.enabled", true);
+
+add_task(async function testContentBlockingMessage() {
+  const CONTENT_BLOCKING_GROUP_LABEL = "Content blocked messages";
+
+  // Enable groupWarning and persist log
+  await pushPref("devtools.webconsole.groupWarningMessages", true);
+
+  const hud = await openNewTabAndConsole(TEST_URI);
+
+  info("Log a console.group");
+  const onGroupMessage = waitForMessage(hud, "myGroup");
+  let onInGroupMessage = waitForMessage(hud, "log in group");
+  ContentTask.spawn(gBrowser.selectedBrowser, null, function() {
+    content.wrappedJSObject.console.group("myGroup");
+    content.wrappedJSObject.console.log("log in group");
+  });
+  const {node: consoleGroupMessageNode} = await onGroupMessage;
+  await onInGroupMessage;
+
+  checkConsoleOutputForWarningGroup(hud, [
+    `▼ myGroup`,
+    `| log in group`,
+  ]);
+
+  info("Log a tracking protection message to check a single message isn't grouped");
+  const now = Date.now();
+  let onContentBlockingWarningMessage = waitForMessage(hud, BLOCKED_URL, ".warn");
+  emitStorageAccessBlockedMessage(now);
+  await onContentBlockingWarningMessage;
+
+  checkConsoleOutputForWarningGroup(hud, [
+    `▼ myGroup`,
+    `| log in group`,
+    `| ${BLOCKED_URL}?${now}-1`,
+  ]);
+
+  info("Collapse the console.group");
+  consoleGroupMessageNode.querySelector(".arrow").click();
+  await waitFor(() => !findMessage(hud, "log in group"));
+
+  checkConsoleOutputForWarningGroup(hud, [
+    `▶︎ myGroup`,
+  ]);
+
+  info("Expand the console.group");
+  consoleGroupMessageNode.querySelector(".arrow").click();
+  await waitFor(() => findMessage(hud, "log in group"));
+
+  checkConsoleOutputForWarningGroup(hud, [
+    `▼ myGroup`,
+    `| log in group`,
+    `| ${BLOCKED_URL}?${now}-1`,
+  ]);
+
+  info("Log a second tracking protection message to check that it causes the grouping");
+  const onContentBlockingWarningGroupMessage =
+    waitForMessage(hud, CONTENT_BLOCKING_GROUP_LABEL, ".warn");
+  emitStorageAccessBlockedMessage(now);
+  const {node: warningGroupNode} = await onContentBlockingWarningGroupMessage;
+
+  checkConsoleOutputForWarningGroup(hud, [
+    `▶︎⚠ ${CONTENT_BLOCKING_GROUP_LABEL}`,
+    `▼ myGroup`,
+    `| log in group`,
+  ]);
+
+  info("Open the warning group");
+  warningGroupNode.querySelector(".arrow").click();
+  await waitFor(() => findMessage(hud, BLOCKED_URL));
+
+  checkConsoleOutputForWarningGroup(hud, [
+    `▼︎⚠ ${CONTENT_BLOCKING_GROUP_LABEL}`,
+    `| ${BLOCKED_URL}?${now}-1`,
+    `| ${BLOCKED_URL}?${now}-2`,
+    `▼ myGroup`,
+    `| log in group`,
+  ]);
+
+  info("Log a new tracking protection message to check it appears inside the group");
+  onContentBlockingWarningMessage =
+    waitForMessage(hud, BLOCKED_URL, ".warn");
+  emitStorageAccessBlockedMessage(now);
+  await onContentBlockingWarningMessage;
+  ok(true, "The new tracking protection message is displayed");
+
+  checkConsoleOutputForWarningGroup(hud, [
+    `▼︎⚠ ${CONTENT_BLOCKING_GROUP_LABEL}`,
+    `| ${BLOCKED_URL}?${now}-1`,
+    `| ${BLOCKED_URL}?${now}-2`,
+    `| ${BLOCKED_URL}?${now}-3`,
+    `▼ myGroup`,
+    `| log in group`,
+  ]);
+
+  info("Log a simple message to check if it goes into the console.group");
+  onInGroupMessage = waitForMessage(hud, "log in group");
+  ContentTask.spawn(gBrowser.selectedBrowser, null, function() {
+    content.wrappedJSObject.console.log("second log in group");
+  });
+  await onInGroupMessage;
+
+  checkConsoleOutputForWarningGroup(hud, [
+    `▼︎⚠ ${CONTENT_BLOCKING_GROUP_LABEL}`,
+    `| ${BLOCKED_URL}?${now}-1`,
+    `| ${BLOCKED_URL}?${now}-2`,
+    `| ${BLOCKED_URL}?${now}-3`,
+    `▼ myGroup`,
+    `| log in group`,
+    `| second log in group`,
+  ]);
+
+  info("Collapse the console.group");
+  consoleGroupMessageNode.querySelector(".arrow").click();
+  await waitFor(() => !findMessage(hud, "log in group"));
+
+  checkConsoleOutputForWarningGroup(hud, [
+    `▼︎⚠ ${CONTENT_BLOCKING_GROUP_LABEL}`,
+    `| ${BLOCKED_URL}?${now}-1`,
+    `| ${BLOCKED_URL}?${now}-2`,
+    `| ${BLOCKED_URL}?${now}-3`,
+    `▶︎ myGroup`,
+  ]);
+
+  info("Close the warning group");
+  warningGroupNode.querySelector(".arrow").click();
+  await waitFor(() => !findMessage(hud, BLOCKED_URL));
+
+  checkConsoleOutputForWarningGroup(hud, [
+    `▶︎⚠ ${CONTENT_BLOCKING_GROUP_LABEL}`,
+    `▶︎ myGroup`,
+  ]);
+
+  info("Open the console group");
+  consoleGroupMessageNode.querySelector(".arrow").click();
+  await waitFor(() => findMessage(hud, "log in group"));
+
+  checkConsoleOutputForWarningGroup(hud, [
+    `▶︎⚠ ${CONTENT_BLOCKING_GROUP_LABEL}`,
+    `▼ myGroup`,
+    `| log in group`,
+    `| second log in group`,
+  ]);
+
+  info("Collapse the console.group");
+  consoleGroupMessageNode.querySelector(".arrow").click();
+  await waitFor(() => !findMessage(hud, "log in group"));
+
+  checkConsoleOutputForWarningGroup(hud, [
+    `▶︎⚠ ${CONTENT_BLOCKING_GROUP_LABEL}`,
+    `▶︎ myGroup`,
+  ]);
+
+  info("Open the warning group");
+  warningGroupNode.querySelector(".arrow").click();
+  await waitFor(() => findMessage(hud, BLOCKED_URL));
+
+  checkConsoleOutputForWarningGroup(hud, [
+    `▼︎⚠ ${CONTENT_BLOCKING_GROUP_LABEL}`,
+    `| ${BLOCKED_URL}?${now}-1`,
+    `| ${BLOCKED_URL}?${now}-2`,
+    `| ${BLOCKED_URL}?${now}-3`,
+    `▶︎ myGroup`,
+  ]);
+});
+
+let cpt = 0;
+/**
+ * Emit a Content Blocking message. This is done by loading an image from an origin
+ * tagged as tracker. The image is loaded with a incremented counter query parameter
+ * each time so we can get the warning message.
+ */
+function emitStorageAccessBlockedMessage(prefix) {
+  const url = `${BLOCKED_URL}?${prefix}-${++cpt}`;
+  ContentTask.spawn(gBrowser.selectedBrowser, url, function(innerURL) {
+    content.wrappedJSObject.loadImage(innerURL);
+  });
+}
diff --git a/devtools/client/webconsole/test/mochitest/head.js b/devtools/client/webconsole/test/mochitest/head.js
index b69e9bf7d876..26d557ee7d78 100644
--- a/devtools/client/webconsole/test/mochitest/head.js
+++ b/devtools/client/webconsole/test/mochitest/head.js
@@ -1245,7 +1245,7 @@ function isScrolledToBottom(container) {
  * @param {Array<String>} expectedMessages: An array of string representing the messages
  *                        from the output. This can only be a part of the string of the
  *                        message.
- *                        Start the string with "▶︎ " or "▼ " to indicate that the
+ *                        Start the string with "▶︎⚠ " or "▼⚠ " to indicate that the
  *                        message is a warningGroup (with respectively an open or
  *                        collapsed arrow).
  *                        Start the string with "|︎ " to indicate that the message is
@@ -1254,23 +1254,65 @@ function isScrolledToBottom(container) {
 function checkConsoleOutputForWarningGroup(hud, expectedMessages) {
   const messages = findMessages(hud, "");
   is(messages.length, expectedMessages.length, "Got the expected number of messages");
+
+  const isInWarningGroup = index => {
+    const message = expectedMessages[index];
+    if (!message.startsWith("|")) {
+      return false;
+    }
+    const groups = expectedMessages.slice(0, index)
+      .reverse()
+      .filter(m => !m.startsWith("|"));
+    if (groups.length === 0) {
+      ok(false, "Unexpected structure: an indented message isn't in a group");
+    }
+
+    return groups[0].startsWith("▶︎⚠") || groups[0].startsWith("▼⚠");
+  };
+
   expectedMessages.forEach((expectedMessage, i) => {
     const message = messages[i];
+    info(`Checking "${expectedMessage}"`);
+
+    // Collapsed Warning group
+    if (expectedMessage.startsWith("▶︎⚠")) {
+      is(message.querySelector(".arrow").getAttribute("aria-expanded"), "false",
+        "There's a collapsed arrow");
+      is(message.querySelector(".indent").getAttribute("data-indent"), "0",
+        "The warningGroup has the expected indent");
+      expectedMessage = expectedMessage.replace("▶︎⚠ ", "");
+    }
+
+    // Expanded Warning group
+    if (expectedMessage.startsWith("▼︎⚠")) {
+      is(message.querySelector(".arrow").getAttribute("aria-expanded"), "true",
+        "There's an expanded arrow");
+      is(message.querySelector(".indent").getAttribute("data-indent"), "0",
+        "The warningGroup has the expected indent");
+      expectedMessage = expectedMessage.replace("▼︎⚠ ", "");
+    }
+
+    // Collapsed console.group
     if (expectedMessage.startsWith("▶︎")) {
       is(message.querySelector(".arrow").getAttribute("aria-expanded"), "false",
         "There's a collapsed arrow");
       expectedMessage = expectedMessage.replace("▶︎ ", "");
     }
 
+    // Expanded console.group
     if (expectedMessage.startsWith("▼")) {
       is(message.querySelector(".arrow").getAttribute("aria-expanded"), "true",
         "There's an expanded arrow");
-      expectedMessage = expectedMessage.replace("▼︎ ", "");
+      expectedMessage = expectedMessage.replace("▼ ", "");
     }
 
+    // In-group message
     if (expectedMessage.startsWith("|")) {
-      is(message.querySelector(".indent.warning-indent").getAttribute("data-indent"), "1",
-        "The message has the expected indent");
+      if (isInWarningGroup(i)) {
+        is(message.querySelector(".indent.warning-indent").getAttribute("data-indent"),
+          "1", "The message has the expected indent");
+      }
+
       expectedMessage = expectedMessage.replace("| ", "");
     }