Browse workspace commit history

Traceability

• Spec ID: studio-commit-view
• Status: Implemented (automatic pagination follow-up; Windows CI receipt pending)

Intent

Better Harness Studio organizes evidence around Intent, Session, Commit, and Artifact. Add a read-only Commit workbench for the currently opened local workspace so a reviewer can trace Session activity and produced Artifacts back to repository history without leaving Studio.

The interaction is based on the Git Log panel in /Users/phodal/ai/routa-js:

• git-log-panel.tsx owns the docked refs, log, and detail layout;
• refs-tree.tsx exposes HEAD, local branches, remote branches grouped by remote, and tags as reachability filters;
• commit-list.tsx exposes a graph, ref labels, summary, author, date, hash, selection, and incremental loading;
• commit-detail-panel.tsx exposes the full message, author, timestamp, parents, changed-file states, and line totals;
• use-git-log.ts owns refresh, search debounce, branch-filter state, selection, detail loading, and pagination;
• /api/git/refs, /api/git/log, and /api/git/commit provide the real Git adapter contract.

Routa's April 2026 incident record also establishes required failure guards: commit records must not be split by multiline messages, workspace/ref changes must not create reload loops, and local/remote branch filters must use the same contract. Better Harness retains those behaviors but binds every Git read to the server-owned open workspace instead of accepting an arbitrary client path.

Acceptance Scenarios

• AC-1: When the opened local workspace is a Git repository, Studio navigation presents a Commit workbench and identifies the current branch without exposing the absolute repository path.
• AC-2: The refs pane lists current HEAD, local branches, remote branches grouped by remote, and tags. Selecting any combination filters the log to commits reachable from those exact refs; clearing filters restores all refs.
• AC-3: The commit table renders date-ordered history with a stable topology graph, ref labels, summary, author, relative date, and short hash. It loads a bounded first page and can request later pages without duplicates.
• AC-4: Search matches commit hash, subject, author name, or author email and is safe for multiline commit bodies. Empty repositories and zero matches render an explicit empty state instead of an indefinite loader.
• AC-5: Selecting a commit renders its full message, immutable author/time/hash metadata, parents, changed-file status, rename origin, additions, and deletions. Selecting a changed text file renders that commit's patch; binary or unavailable patches retain an honest no-diff state.
• AC-6: All Git operations are read-only, workspace-scoped, argv-based, bounded, and work on Windows, macOS, and Linux. Invalid refs, revisions, limits, or unavailable repositories return stable client errors without leaking the workspace's absolute path or raw Git stderr.
• AC-7: The wide layout uses refs, log, and detail panes; compact and narrow layouts preserve the log as the primary decision surface and expose refs and detail through bounded responsive panes. Keyboard focus, selection semantics, overflow, and loading/error states remain usable.
• AC-8: Opening another workspace invalidates Commit state and reloads refs and history for the new repository without carrying prior filters or selection.
• AC-9: A workspace selected anywhere inside a Git worktree resolves one canonical repository root. Commit paths, repository labels, details, and patches use that root consistently without broadening any non-Git Studio capability.
• AC-10: Merge commit details and patches compare against the first parent by default, so a merge never reports zero changed files merely because Git's default combined-diff presentation omitted them.
• AC-11: History pagination uses an opaque continuation cursor, keeps the graph stable across pages, exposes an honest 5,000-row presentation cap, and leaves already loaded commits usable when a later page fails. A failed automatic page load pauses further attempts until the user explicitly retries.
• AC-12: The ordinary refs -> first history page -> commit -> patch flow reuses workspace refs and commit detail instead of repeating full Git reads. Git execution failures remain sanitized errors and are never converted into an empty repository result.
• AC-13: The commit table virtualizes accumulated rows and automatically requests the next cursor page as the final loaded rows enter the viewport at wide, compact, and narrow widths. It exposes loading progress without a manual Load more action, keeps an explicit Retry action after failure, and labels search according to its actual subject/hash/author contract.
• AC-14: Git repository labels and their test fixtures derive native filesystem basenames with the host path implementation. Windows drive-letter and backslash paths never become the full repository label, while browser-facing payloads still redact the absolute repository root on every platform.
• AC-15: Commit topology uses the fixed categorical scale without assigning the primary interaction blue to the default lane. A lane keeps one recognizable color across its line and node, merge nodes remain distinguishable without color alone, and the node cutout follows normal, hover, and selected row surfaces in both dark and light themes.

Non-goals

• Checking out, creating, renaming, merging, rebasing, resetting, deleting, or pushing branches.
• Staging files, editing the working tree, creating commits, or resolving merge conflicts.
• Fetching from remotes or claiming that locally cached remote refs are current.
• Multi-repository selection inside one Studio workspace. Studio's existing workspace chooser remains the repository boundary.
• Mapping individual Session events to commits without explicit retained evidence that establishes that relation.
• Reproducing Routa's Tailwind styling or its simplified two-lane merge graph.

Plan and Tasks

1. Define a versioned, browser-safe Git history model for refs, paged commits, graph edges, commit details, changed files, and per-file patches.
2. Add one capability-owned server module that executes git with argv arrays, parses NUL/unit-separated records, validates refs and SHAs, applies bounded pagination/search, and computes graph lanes from parent topology.
3. Mount workspace-scoped read routes for repository status, refs, log, commit detail, and file patch. The server resolves the repository from its own selected-workspace state; browser requests never send a filesystem path.
4. Add a Commit destination and workbench to the existing Studio shell. Keep the central log primary, use Phosphor icons and shared semantic tokens, and preserve current Artifact Preview worktree changes.
5. Add behavior tests for Git parsing, ref filtering, pagination, multiline messages, rename/binary stats, invalid input, workspace switching, shell availability, and UI-visible model helpers.
6. Run focused type/build/tests, the repository's preview smoke checks, and Playwright review at wide, compact, and narrow widths with console/page-error inspection and screenshots outside tracked source.
7. Resolve and retain the canonical Git root when a workspace opens; define first-parent merge comparison once and reuse it for status, stats, and patch.
8. Replace offset pagination with a query-bound continuation cursor carrying graph lane state. Reuse the refs snapshot and a bounded commit-detail cache, stop cleanly at 5,000 visible rows, and preserve prior pages on failure.
9. Virtualize commit rows with the existing TanStack dependency, trigger cursor pagination when the virtualized viewport reaches the final loaded rows, retain explicit retry after a page failure, give the log grid stable toolbar/status/content/footer rows, and make search copy honest.
10. Remove POSIX-only path splitting from the Git history fixture and document the repository-wide boundary between native filesystem paths, portable protocol paths, line endings, and shell execution.
11. Reorder existing categorical tokens for Git lanes, make segment opacity consistent around nodes, render a redundant merge ring, and bind the node cutout to the actual row state rather than the workspace background.

Test and Review Evidence

• AC-1, AC-6, AC-8: server tests using temporary Git repositories and two independently initialized workspaces; assert response shapes, redaction, and workspace rebinding.
• AC-2, AC-3, AC-4: Git history unit tests with local branches, a bare remote, tags, a merge, multiline bodies, search, and page boundaries.
• AC-5: server/model tests for modified, added, deleted, renamed, and binary files plus exact file-patch selection.
• AC-1, AC-7: Studio shell model tests and Playwright navigation, keyboard, responsive-overflow, console, and screenshot evidence.
• Focused commands:
  • npm run build --workspace @qoder-ai/harness-studio
  • npm exec --workspace @qoder-ai/harness-studio -- vitest run test/git-history.test.ts test/git-history-server.test.ts test/studio-shell-model.test.ts
  • npm exec --workspace @qoder-ai/harness-studio -- playwright test test/browser/git-history.spec.mjs
  • npm run preview, then request http://localhost:58575/health and http://localhost:58575/canvas-module.js
• Risk: Git output is adversarial structured data. Delimiter-safe parsing, exact ref allowlisting, bounded buffers/results, revision validation, and stderr redaction are required before the route can be considered implemented.
• Risk: the base branch includes separately committed Artifact Preview work in the Studio shell and server. Keep Commit View review evidence scoped to the files and tests listed here rather than treating adjacent history as proof.
• AC-9, AC-10: add nested-worktree and merge-first-parent fixtures that assert non-empty, exact patches.
• AC-11, AC-12: assert cursor query binding, page uniqueness, the 5,000-row terminal receipt, cached HTTP reads, and sanitized Git execution failures.
• AC-11, AC-13: scroll the virtualized browser table to trigger the next page without a manual action, inject one page failure, explicitly retry, and inspect DOM bounds at wide, compact, and narrow widths.
• AC-14: run the Git history fixture on the host-native path implementation and retain the GitHub Actions Windows job as the authoritative backslash/drive receipt; local non-Windows runs are supporting evidence, not Windows proof.
• AC-15: inspect computed SVG fill/stroke and merge-node structure in Playwright, then review wide, compact, and narrow screenshots plus a light-theme wide screenshot for lane identity, row-state cutouts, contrast, and console/page errors.

Implementation Evidence

• AC-1 through AC-6 and AC-8 through AC-12: git-history.test.ts, git-history-server.test.ts, and the full Harness Studio Vitest suite pass with real temporary Git repositories (24 files, 151 tests). The focused Git contract suite passes 8 tests, including nested worktrees, first-parent merge detail/patch, signed cursor binding, Git failures, and the 5,000-row terminal cap.
• AC-2 through AC-5, AC-7, AC-11, and AC-13: git-history.spec.mjs passes a real browser flow for ref filtering, author search, automatic cursor pagination at the virtualized scroll boundary, explicit retry after an injected page failure, bounded virtual rows, commit/file selection, and patch rendering at 1440x960, 900x760, and 390x844 with no unexpected console/page errors or horizontal overflow. The injected 422 page failure produces one expected browser resource error and leaves prior rows usable.
• The current better-harness repository was paged through all 326 reachable commits: order exactly matches git log --date-order, all SHAs are unique, 59 merges retain valid graph edges, and no commits are omitted.
• A fresh local HTTP run measured refs at 21.1 ms, first 40-row history at 33.4 ms, the next page at 16.8 ms, commit detail at 34.5 ms, and the cached-detail patch route at 11.0 ms on this checkout. These timings are observational, not a cross-machine performance threshold.
• AC-14: the Git fixture now derives the expected repository label with native node:path.basename instead of POSIX-only string splitting. The focused Git history suite passes (7 tests), Studio typecheck passes, the full Studio suite passes (24 files, 151 tests), and the doc-link suite passes (8 tests). A post-change Windows Actions run has not yet been observed, so this is implemented locally but not claimed as fresh Windows CI proof.
• AC-15: the browser verifies that lane zero resolves to categorical amber rather than the primary interaction blue, active and outgoing segments keep at least 0.8 opacity, merge commits render a redundant double ring, and the node cutout exactly matches selected-row backgrounds in dark and light themes. Wide dark/light, compact, and narrow screenshots were reviewed. The clean candidate passes the full Studio suite (24 files, 151 tests), the focused Git browser scenario, the doc-link suite (8 tests), and git diff --check.
• The automatic pagination follow-up passes Studio typecheck/build, the focused Git contract and shell suite (3 files, 14 tests), the focused Git browser scenario, preview smoke checks for /health and /canvas-module.js, and git diff --check. The full Studio unit suite was also run: 37 files and 233 tests pass, while two unrelated DOCX/XLSX artifact-server descriptor expectations fail against the configured Qoder Canvas adapters.
• Windows CI remains pending; the local macOS verification does not establish a fresh cross-platform receipt.