feat(ask): start chat from selected code range

[nikhil008-git]

Summary

Adds an “Ask Sourcebot” action to the existing code-selection popover in Browse and search previews.

When code is selected, Ask Sourcebot:

• Creates a new chat.
• Seeds the prompt with Explain this selected code.
• Attaches the repository, revision, file path, and selected line range.
• Resolves the file server-side at the selected revision.
• Sends only the selected lines to the model with original line numbers.
• Keeps Share selection behavior unchanged.

This implements issue #1534 Option A only. Side panels and inline conversations are out of scope.

Screenshots

Testing

• Focused web tests pass: 11 files, 251 tests.
• Web lint passes.
• Manual Ask testing is blocked locally because this deployment has no Ask Sourcebot entitlement; the button correctly
  reports that limitation.

Use the first screenshot for Screenshots. Put the entitlement-error screenshot under Testing or omit it if you want
the PR to look cleaner.

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Note

Low Risk
Changes are scoped to Ask UX and prompt assembly for optional line ranges; invalid ranges fail safe and existing full-file behavior remains when no range is set.

Overview
Adds Ask SourceBot to the code-selection popover in Browse (and shared code previews): alongside Share selection, users can open a new Ask chat seeded with Explain this selected code. and a ranged file source for the current repo, revision, path, and selected lines.

Chat creation uses new createChatFromSource on useCreateNewChatThread, which builds the user message via createUIMessage with optional explicitSources (not only file mentions).

Agent / prompt path introduces sliceFileSourceForPrompt so the server still loads the file at the chosen revision but injects only the selected slice into the dynamic <files> block, with selected_lines metadata and addLineNumbers using the real start line. Invalid ranges are dropped with a warning.

Types extend FileSource with an optional validated range (startLine / endLine) in chat and tools schemas.

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Summary by CodeRabbit

• New Features

  • Added an “Ask SourceBot” option to the file editor context menu.
  • Start chats from a selected file or specific line range for focused code explanations.
  • Preserve selected ranges and original line numbering in chat prompts.

• Bug Fixes

  • Safely handle invalid or reversed line ranges.

• Tests

  • Added coverage for ranged sources, offsets, full-file prompts, and invalid selections.

[coderabbitai]

Walkthrough

The editor context menu now sends selected file ranges to a new SourceBot chat. File-source validation, prompt slicing, line offsets, range metadata, explicit source propagation, and chat creation support the flow.

Changes

Selected SourceBot Chat

Layer / File(s)	Summary
Source range contract and prompt handling packages/web/src/features/tools/types.ts, packages/web/src/ee/features/chat/agent.ts, packages/web/src/ee/features/chat/agent.test.ts	FileSource supports validated line ranges. Prompt generation slices selected lines, preserves offsets, includes range metadata, and excludes invalid ranges.
Explicit source chat creation packages/web/src/features/chat/utils.ts, packages/web/src/features/chat/utils.test.ts, packages/web/src/features/chat/useCreateNewChatThread.ts	createUIMessage accepts explicit sources. The chat thread hook creates and navigates to a chat containing the selected source.
Editor SourceBot action packages/web/src/app/(app)/components/editorContextMenu.tsx	The context menu converts the editor selection into file and range metadata and adds an “Ask SourceBot” action.

Estimated code review effort: 3 (Moderate) | ~20 minutes

Sequence Diagram(s)

sequenceDiagram
  participant EditorContextMenu
  participant useCreateNewChatThread
  participant createUIMessage
  participant ChatNavigation
  EditorContextMenu->>useCreateNewChatThread: createChatFromSource(selected file range)
  useCreateNewChatThread->>createUIMessage: build message with explicit source
  createUIMessage-->>useCreateNewChatThread: data-source message part
  useCreateNewChatThread->>ChatNavigation: persist chat state and navigate

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Possibly related issues

• [FR] Add “Ask Sourcebot” to code selections with attached source context #1534: The PR adds the requested Ask SourceBot action for selected code ranges and attaches the selection to a new chat.

Possibly related PRs

• sourcebot-dev/sourcebot#393: Related to agent.ts, source handling, and line-range metadata for file references.
• sourcebot-dev/sourcebot#1205: Related to FileSource handling in utils.ts and source metadata propagation.
• sourcebot-dev/sourcebot#1366: Related to agent.ts prompt construction and the SourceBot chat flow.

Suggested reviewers: brendan-kellam

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title clearly and concisely describes starting a chat from a selected code range, which is the main change.

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests

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[nikhil008-git]

closes #1534

[coderabbitai]

Actionable comments posted: 1

🤖 Prompt for all review comments with AI agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

Inline comments:
In `@packages/web/src/ee/features/chat/agent.ts`:
- Around line 1033-1034: Update the files parameter type in createPrompt to
include the range and lineOffset properties accessed by the prompt template,
using types consistent with their existing usage in the files.map rendering and
addLineNumbers call.

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Fix all unresolved CodeRabbit comments on this PR:

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• Create a new PR with the fixes

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ℹ️ Review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro Plus

Run ID: ed24b0e1-853e-4d18-ac94-7a2ce45a6963

📥 Commits

Reviewing files that changed from the base of the PR and between 472692a and 865aac8.

📒 Files selected for processing (7)

• packages/web/src/app/(app)/components/editorContextMenu.tsx
• packages/web/src/ee/features/chat/agent.test.ts
• packages/web/src/ee/features/chat/agent.ts
• packages/web/src/features/chat/useCreateNewChatThread.ts
• packages/web/src/features/chat/utils.test.ts
• packages/web/src/features/chat/utils.ts
• packages/web/src/features/tools/types.ts

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Cursor Bugbot has reviewed your changes using high effort and found 1 potential issue.

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MCP prefs ignored on Ask

Medium Severity

createChatFromSource hardcodes disabledMcpServerIds to [] in both the message metadata and session state, so chats started from a code selection always re-enable every MCP server. createNewChatThread still honors DISABLED_MCP_SERVER_IDS_LOCAL_STORAGE_KEY, so Ask-from-selection bypasses the user’s saved connector preferences.

 

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