Adds the `head_branch` field (the source/feature branch name of a PR) to
the diff status pipeline. Previously only `base_branch` (target branch)
and the head commit SHA were captured from the GitHub API, but not the
head branch name itself.
## Changes
- **Migration 438**: Add `head_branch` nullable TEXT column to
`chat_diff_statuses`
- **gitprovider**: Parse `head.ref` from the GitHub API response
(alongside `head.sha`) and add `HeadBranch` to `PRStatus`
- **gitsync**: Wire `HeadBranch` through `refreshOne()` into the DB
upsert params
- **worker**: Map `HeadBranch` in `chatDiffStatusFromRow()`
- **coderd**: Convert `HeadBranch` in `convertChatDiffStatus()`
- **codersdk**: Expose as `head_branch` (`*string`, omitempty) in
`ChatDiffStatus` API response
- **Tests**: Updated `github_test.go` pull JSON fixtures and assertions
## Problem
The gitsync worker polls every 10s and refreshes up to 50 stale
`chat_diff_status` rows **sequentially**, sharing a single 10-second
context timeout. With 50 rows × 1–3 HTTP calls each, the timeout is
exhausted quickly, causing cascading `context deadline exceeded` errors.
Rows with no linked OAuth token (`ErrNoTokenAvailable`) fail fast but
recur every 120s, wasting batch capacity.
## Solution
Three targeted fixes:
### 1. Concurrent refresh processing
`Refresher.Refresh()` now launches goroutines bounded by a semaphore
(`defaultConcurrency = 10`). Provider/token resolution remains
sequential (fast DB lookups); only the HTTP calls run in parallel.
Per-group rate-limit detection uses `atomic.Pointer[RateLimitError]`
with best-effort skip of remaining rows — a rate-limit hit on one
provider doesn't stall requests to other providers.
### 2. Decoupled tick timeout
New `defaultTickTimeout = 30s`, separate from `defaultInterval = 10s`.
The `tick()` method uses `tickTimeout` for its context deadline, giving
concurrent HTTP calls enough headroom to complete without stalling the
next polling cycle.
### 3. Longer backoff for no-token errors
New `NoTokenBackoff = 10 * time.Minute` (exported). When `errors.Is(err,
ErrNoTokenAvailable)`, the worker applies a 10-minute backoff instead of
`DiffStatusTTL` (2 minutes). Retrying every 2 minutes is pointless until
the user manually links their external auth account.
## Design decisions
- Both `NewRefresher` and `NewWorker` accept variadic option functions
(`RefresherOption`, `WorkerOption`) for backward compatibility —
existing callers in `coderd/coderd.go` need no changes.
- `WithConcurrency(n)` and `WithTickTimeout(d)` are available for tests
and future tuning.
- Added `resolvedGroup` struct to cleanly separate the pre-resolution
phase from the concurrent execution phase.
## Testing
- **`TestRefresher_RateLimitSkipsRemainingInGroup`** — rewritten to be
goroutine-order-independent (verifies aggregate counts instead of
per-index results).
- **`TestRefresher_ConcurrentProcessing`** — new test using a gate
channel to prove N goroutines enter `FetchPullRequestStatus`
simultaneously.
- **`TestWorker_RefresherError_BacksOffRow`** — rewritten to use
branch-name-based failure determination instead of non-deterministic
`callCount`.
- **`TestWorker_NoTokenBackoff`** — new test verifying
`ErrNoTokenAvailable` triggers 10-minute backoff.
- All tests pass under `-race -count=3`.
## Problem
Two separate code paths refreshed chat diff statuses:
1. **HTTP handler** (`refreshChatDiffStatus`): resolved
provider/token/status inline, ran under the user's context. Worked fine
because the user owns their external auth links.
2. **Background worker** (`Refresher.Refresh`): ran under `AsChatd`
context, which lacked `ActionReadPersonal` on `ResourceUser`.
`GetExternalAuthLink` failed silently (`if err != nil { continue }`),
returning `ErrNoTokenAvailable` every time. Chat diff statuses got
`git_branch`/`git_remote_origin` from `MarkStale` but `refreshed_at`,
`url`, `pull_request_state` stayed nil.
Having two paths also meant bug fixes had to be applied twice.
## Fix
- **`Worker.RefreshChat`**: New method for synchronous, on-demand
refresh of a single chat. Uses the same `Refresher.Refresh` pipeline as
the background `tick()`. Called by the HTTP handler for instant
response.
- **`resolveChatGitAccessToken`**: Uses
`dbauthz.AsSystemRestricted(ctx)` specifically for `GetExternalAuthLink`
and `RefreshToken` calls. This is scoped to just those DB operations
rather than broadening the chatd RBAC role.
- **Removed**: `refreshChatDiffStatus`, `shouldRefreshChatDiffStatus`,
`resolveChatDiffStatusWithOptions` (all replaced by the single
`RefreshChat` path).
## Tests
Added 4 tests for `Worker.RefreshChat`:
- `TestRefreshChat_Success`: full refresh + upsert + publish
- `TestRefreshChat_NoPR`: no PR exists yet, nil result
- `TestRefreshChat_RefreshError`: provider resolution fails
- `TestRefreshChat_UpsertError`: refresh succeeds but DB write fails
## Why tests didn't catch the original bug
- Worker tests used mock stores (no dbauthz) and fake token resolvers
(hardcoded lambdas)
- No integration test exercised `AsChatd` -> `resolveChatGitAccessToken`
-> `GetExternalAuthLink` through dbauthz
- Adds `_API_BASE_URL` to `CODER_EXTERNAL_AUTH_CONFIG_`
- Extracts and refactors existing GitHub PR sync logic to new packages
`coderd/gitsync` and `coderd/externalauth/gitprovider`
- Associated wiring and tests
Created using Opus 4.6