warp/specs/APP-3922/TECH.md

APP-3922: Create PR Dialog — Tech Spec

Problem

APP-3920 unified commit, push, and publish into a single GitDialog view and collapsed the event contract to Completed | Cancelled (each mode owns its own toasts and error messaging). The git operations button can reach PrimaryGitActionMode::CreatePr (everything pushed, no PR, not on main), but OpenCreatePrDialog and CommitAndCreatePr actions were stubbed as TODOs. This branch adds the PR dialog as a third mode alongside commit and push, wires the "Commit and create PR" chain in commit mode, and includes a few related fixes.

Relevant Code

• app/src/code_review/git_dialog/pr.rs — new submodule for the CreatePr mode
• app/src/code_review/git_dialog/mod.rs — extended with CreatePr(PrState), Pr(PrSubAction), new_for_pr(), and mode dispatch
• app/src/code_review/git_dialog/commit.rs — extended with CommitAndCreatePr intent, allow_create_pr: bool parameter, third intent button (hidden when the intent isn't meaningful), a private CommitOutcome enum for confirm results, and a chained run_commit → run_push → create_pr async
• app/src/code_review/code_review_view.rs — open_pr_dialog(), allow_create_pr computed and passed through open_commit_dialog(), OpenCreatePrDialog / CommitAndCreatePr action handlers, update_git_operations_ui refresh on NewDiffsComputed
• app/src/util/git.rs — get_branch_diff_entries() (branch-level numstat diff). create_pr() and PrInfo already existed.

Current State

GitDialog owns commit and push modes with a shared shape: per-mode state struct, body renderer, confirm async, and dispatch in mod.rs. Each mode calls show_toast / user_facing_git_error (declared in git_dialog/mod.rs) on success and failure, then emits GitDialogEvent::Completed. The parent closes the dialog and refreshes metadata; it no longer knows anything about outcomes. gh CLI helpers (run_gh_command, get_pr_for_branch, PrInfo, create_pr) already exist.

Proposed Changes

1. PR mode for GitDialog (git_dialog/pr.rs)

A new submodule, following the same shape as commit.rs and push.rs. State:

pub struct PrState {
    file_changes: Vec<FileChangeEntry>,
    changes_expanded: bool,
    summary_mouse_state: MouseStateHandle,
    changes_scroll_state: ClippedScrollStateHandle,
}

Sub-action:

pub enum PrSubAction {
    ToggleChangesExpanded,
}

Body: branch header + "Changes" section with aggregate stats (file count, +additions, -deletions) and expandable per-file list (scrollable, max 130px). Uses the shared render_branch_section / render_chevron_icon / render_file_list helpers in git_dialog/mod.rs. Constructor: pr::new_state(repo_path, ctx) spawns get_branch_diff_entries to populate file_changes. Confirm: pr::start_confirm spawns create_pr(&repo_path).

• On success: calls show_pr_created_toast(&pr_info, ctx) (see below).
• On failure: logs the raw error and calls show_toast(user_facing_git_error(&err), ctx).
• Either way emits GitDialogEvent::Completed. Toast helper: pr::show_pr_created_toast(pr_info, ctx) — ephemeral DismissibleToast with message "PR successfully created." and a clickable "Open PR" ToastLink pointing at pr_info.url. Declared pub(super) so commit.rs can reuse it for the CommitAndCreatePr chain. Labels/icon: title = "Create pull request"; confirm button = "Create PR" / Icon::Github; loading = "Creating…".

2. GitDialog mode dispatch (git_dialog/mod.rs)

• New variant GitDialogMode::CreatePr(PrState)
• New variant GitDialogAction::Pr(PrSubAction)
• New constructor GitDialog::new_for_pr(repo_path, branch_name, ctx)
• Title / body / focus / confirm / sub-action dispatch extended for CreatePr
• new_for_commit signature grows an allow_create_pr: bool parameter so commit mode can hide its "Commit and create PR" button when the intent isn't meaningful (existing PR or main branch). The caller encodes both conditions into the single boolean so the dialog doesn't need to know the underlying reasons.

3. CommitAndCreatePr intent (git_dialog/commit.rs)

• Adds CommitIntent::CommitAndCreatePr variant
• confirm_label_for / confirm_icon_for / loading_label_for extended
• CommitState gains commit_and_create_pr_button: Option<ViewHandle<ActionButton>> — None when allow_create_pr is false (existing PR or main branch)
• new_state takes allow_create_pr: bool. When false:
  • The "Commit and create PR" button is omitted entirely (not just disabled)
  • A debug_assert! catches callers that dispatched CommitAndCreatePr anyway; in release the subsequent create_pr call surfaces the real gh error via the normal failure path rather than silently rewriting the intent
• apply_intent_selector and render_intent_buttons skip the third button when it's None
• A private CommitOutcome { Committed | Pushed | PrCreated(PrInfo) } enum represents what actually ran, keeping "which stages fired" decoupled from the user's selected intent so the callback can't drift out of sync with the async body.
• start_confirm chains run_commit → run_push (for CommitAndPush or CommitAndCreatePr) → create_pr (for CommitAndCreatePr) in a single ctx.spawn, returning a CommitOutcome
• Success toasts by outcome:
  • Committed → "Changes successfully committed."
  • Pushed → "Changes committed and pushed."
  • PrCreated(pr) → show_pr_created_toast(&pr, ctx) (same link-bearing toast as standalone PR creation)
• Failure → show_toast(user_facing_git_error(...), ctx)
• Either way emits GitDialogEvent::Completed

4. Code review view integration (code_review_view.rs)

• open_pr_dialog(ctx) — uses the existing prepare_git_dialog / attach_git_dialog helpers; constructs GitDialog::new_for_pr(...).
• open_commit_dialog(intent, ctx) — computes allow_create_pr = pr_info.is_none() && !is_on_main_branch() from diff_state_model and passes it through to GitDialog::new_for_commit, so the commit dialog can hide the "Create PR" intent when it isn't meaningful.
• Action wiring:
  • OpenCreatePrDialog → self.open_pr_dialog(ctx) (was TODO)
  • CommitAndCreatePr → self.open_commit_dialog(CommitIntent::CommitAndCreatePr, ctx) (was TODO)
• Git operations button refresh fix: DiffStateModelEvent::NewDiffsComputed handler now calls update_git_operations_ui(ctx) so after a commit the button transitions from "Commit" → "Push" (or "Create PR") without waiting for another event. Parent still knows nothing about outcomes — its attach_git_dialog subscriber remains just Completed → close + refresh and Cancelled → close.

5. Git utility (util/git.rs)

get_branch_diff_entries(repo_path) — returns per-file change stats for the branch diff:

• Detects base branch via detect_main_branch, current branch via detect_current_branch.
• Diffs {base}..origin/{current}, falling back to {base}..HEAD if the remote ref doesn't exist (e.g. branch not yet pushed).
• Parses git diff --numstat into Vec<FileChangeEntry>.

End-to-End Flows

Standalone "Create PR" flow

1. User clicks "Create PR" button → OpenCreatePrDialog action
2. open_pr_dialog(ctx) → GitDialog::new_for_pr(...); pr::new_state spawns get_branch_diff_entries
3. Dialog renders with branch info and change summary
4. User clicks "Create PR" → GitDialogAction::Confirm → pr::start_confirm spawns create_pr
5. Confirm/cancel/close disabled, confirm label reads "Creating…"
6. On success → show_pr_created_toast fires ("PR successfully created." with "Open PR" link) → emits Completed → parent closes dialog + refreshes metadata (header button becomes "PR #N")
7. On error → toast with friendly message → emits Completed → parent closes dialog + refreshes

"Commit and create PR" flow

1. User selects "Commit and create PR" in the commit dialog → CommitIntent::CommitAndCreatePr
2. Confirm handler chains run_commit → run_push → create_pr in a single ctx.spawn
3. On success → show_pr_created_toast(&pr, ctx) → Completed → parent closes dialog + refreshes
4. On failure at any stage → friendly error toast → Completed → parent closes dialog + refreshes

"Commit and create PR" when the intent isn't meaningful (existing PR or main branch)

1. open_commit_dialog computes allow_create_pr from the diff state model (PR info + is_on_main_branch) and passes it to GitDialog::new_for_commit
2. The third intent button is omitted entirely (no disabled dead button)
3. The caller is expected to not dispatch CommitAndCreatePr in this state; a debug_assert! in commit::new_state catches violations in dev builds, and in release the subsequent create_pr failure surfaces via the normal error toast path

Risks and Mitigations

gh CLI not installed or not authenticated

Currently no pre-check. create_pr fails with a descriptive error from gh. The error surfaces as a friendly toast via the unified Failed path. Follow-up: add a gh availability check before enabling the action.

Git operations button not updating after commit

Fixed by calling update_git_operations_ui in the NewDiffsComputed handler, so after a commit triggers a diff reload, the button state is re-evaluated.

Testing and Validation

• Verify PR dialog opens with correct branch name and file change stats.
• Verify expanding changes shows per-file list with correct +/- stats.
• Verify loading state (all three chrome buttons disabled) during PR creation.
• Verify success shows the "PR successfully created." toast with "Open PR" link and header updates to "PR #N".
• Verify error shows friendly error toast and dialog closes.
• Verify "Commit and create PR" chains all three operations and shows the same PR toast on success.
• Verify commit dialog omits the third button entirely when the branch already has a PR OR when on the repo's main branch.
• Verify cancel/close/ESC dismisses the dialog without side effects.
• Verify the git operations button transitions correctly across Commit → Push → Create PR → PR #N.

Follow-ups

• Add gh CLI availability/auth check before enabling "Create PR" and "Commit and create PR" actions.
• Support editing PR title and body (currently uses --fill).
• Support draft PRs.
• Mid-flight mode transitions during CommitAndCreatePr so the dialog reflects "Committing…" → "Pushing…" → "Creating PR…" stages.