Summary

Intent

The changes implement the UI and service layer for a new "natural language tab grouping" feature in Firefox's AI Window. This extends the existing tab closing flow to also support grouping tabs via AI-assisted conversation. Users can ask the AI to group tabs, confirm which tabs to group, see the result, and undo the grouping (which ungroups the tabs). The feature follows the same tool-call pattern already established for closing tabs.

Solution

Service Layer ():

• Added a method that validates candidate tabs (filtering out pinned, already-grouped, and closing tabs), picks an unused color from a predefined palette (with random fallback when all colors are used), and delegates to .
• Added an method that finds a group by ID, iterates through its tabs calling , and returns metadata about the ungrouped tabs.
• Added a static constant and private helpers (, ) for color selection and tab validation.

Orchestration Layer ():

• Introduced new UI type () and update types (, ) for the tab grouping flow.
• Added handler methods (creates a group, records telemetry, transitions to action result) and (ungroups tabs, records undo telemetry, updates UI).
• Refactored by extracting common tab verification logic into a shared method, reused by the new method on .
• Introduced array and to generalize the cancellation/retry flow across both website-confirmation and tab-group-confirmation UIs, replacing hardcoded checks against a single UI type.
• The cancel handler now passes the and the retry flow selects the correct localized retry message based on the cancelled UI type.

Chat Content Component ():

• Added rendering for the UI type, reusing the component with different confirm button labels ("Group" instead of "Close") and passing the and properties.
• Added data-formatting methods (, ) and a dispatcher () to render action results for grouped and ungrouped tabs.
• The undo button now dispatches the correct update type based on using a mapping object ().
• The retry component now uses a dynamic Fluent L10n ID from properties rather than a hardcoded one.

Confirmation Component ():

• Added , , and properties to make the component reusable for both close and group actions.
• The submit event now includes and the close event includes in their detail payloads.

Localization:

• Added Fluent strings for the group action button, grouped/ungrouped result labels, summary messages, and a tab-group-specific retry message.

Persistence ():

• Updated restored-from-DB logic to use the array instead of checking a single UI type, so tab-group confirmations are also correctly marked as restored.

Tests:

• Added xpcshell tests for and covering success, invalid tabs (pinned, grouped, closing), empty input, invalid window, color assignment, and color exhaustion.
• Updated existing browser tests to include in confirmed data payloads.
• Added browser tests for rendering tab-group confirmation UI, action results for grouped/ungrouped tabs, and verifying that submit events carry the .
• Extended mock helpers with , , , , and support.

Code analysis found 1 defect in diff 1302820:

• 1 defect found by eslint (Mozlint)

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If you see a problem in this automated review, please report it here.

You can view these defects in the Diff Detail section of Phabricator diff 1302820.