Record feed tabs review and verification

By architect.

docs/reviews/feed-tabs-summary.md

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+# Feed Tabs — Architect Review
+
+**By architect.**
+
+## Task and commits reviewed
+
+- Task: `feed-tabs` (refactorer handoff
+  `merge_and_process refactorer 4b8b4ed499`, delivered as a one-item `BATCH`).
+- Merged `swarmforge-refactorer` (fast-forward from `de3f1c8`). Commits:
+  - `f3a41de` Specify merged posts feed with Recent/Following tabs (specifier)
+  - `d1372da` Merge Following feed into the posts page as Recent/Following tabs
+    (coder)
+  - `4b8b4ed` Refactor feed tabs: simplify mode loading, add feed-tabs
+    properties (refactorer)
+- Architect review commit: `e4bda31256` (view/controller encapsulation + test
+  consolidation + tool-written mutation and acceptance manifests).
+- Verification record `git_sha`: `e4bda31256` (client).
+- Records/summary commit: this commit.
+
+The feature merges the old `/posts/following` route into `/posts/recent` as a
+row of two mode buttons. On first open the page asks
+`GET /follow/following/:addr`; if the viewer follows at least one account it
+selects Following, otherwise Recent. Switching tabs resets to the first page.
+The `/posts/following` route and navbar item are removed. The new
+`FeedTabsPage` service composes the existing `RecentFeedPage` and
+`FollowingFeedPage` controllers behind injected `memoDb`/`wallet`, and the React
+shell (`components/app-body/posts/index.js`) renders it. Client-only read
+feature; no DB or indexer change.
+
+## Architectural review
+
+- **UI/Core separation (good).** `FeedTabsPage` is pure coordinator logic in
+  `src/services/` with `memoDb` and `wallet` injected; it opens no network, DOM,
+  or wallet IO itself. The React shell constructs `MemoDb` and the controller and
+  maps the snapshot into view state. Acceptance drives the controller directly
+  through the fake memo-db, so core behavior is tested with no UI or IO.
+- **Dependency rule (good).** The view depends on the service; the service
+  depends on the two page controllers and on the `MemoDb` adapter through its
+  constructor. No high-level module reaches around the injected adapter, and the
+  adapter does not reach back into the controller.
+- **Information hiding (one fix).** The controller exposes a tested `getState()`
+  snapshot, but the view was still reading `page.posts`, `page.pagination`,
+  `page.mode`, `page.emptyBecauseNoFollows`, and `page.offset` directly. Routed
+  `showPage` through `getState()` so the controller is the single source of feed
+  state (see Fixes).
+- **Local code quality (one fix).** The two default-mode unit tests were
+  structurally identical and DRY reported them (score 1.00). Consolidated into a
+  table-driven pair with a shared assertion helper. Added initial-state tests to
+  kill mutation survivors the refactorer left (see Fixes).
+- **Delegation, not duplication (accepted).** `FeedTabsPage` owns paging
+  (`nextPage`/`previousPage`/`canLoadMore`) and delegates post loading to the two
+  sub-pages. It computes `emptyBecauseNoFollows` itself from `hasFollows`, which
+  is the correct merged-page semantics (the message shows only when the viewer
+  follows no one). `FollowingFeedPage` still exposes its own
+  `emptyBecauseNoFollows`, but that is the older `/posts/following` contract and
+  is now unused by the tabs flow; it is retained only because
+  `specs/following-feed.feature` still specifies it. Not changed here (specifier
+  owns retiring that feature); noting it as the one remaining conceptual overlap.
+- **Module boundaries (good).** The deleted `following-feed` component left no
+  dangling imports; `FollowingFeedPage` remains as the internal delegate used by
+  `FeedTabsPage`, and `memo-db.js` gained a thin `getFollowing` adapter method
+  next to the existing `getFollowingFeed`.
+
+## Fixes applied
+
+- **View consumes the controller snapshot.** `posts/index.js` `showPage` now
+  reads `page.getState()` instead of five internal fields, keeping the
+  controller's representation hidden behind its public accessor. The injected
+  `memoDb` (needed for author-profile lookup) is still passed explicitly.
+- **Killed four mutation survivors with initial-state tests.** The refactorer's
+  first mutation run left `constructor.offset = 0`, `constructor.hasFollows =
+  false`, `constructor.emptyBecauseNoFollows = false`, and the
+  `canLoadMore() ?? false` default surviving because no test observed an
+  unloaded controller. Added `constructor starts in a neutral, unloaded state`
+  and `canLoadMore is false before any page has been loaded`. Final mutation:
+  **22 killed, 0 survived, 0 uncovered.**
+- **Removed a local test duplicate.** Extracted
+  `assertOnlySelectedFeedLoaded` and folded the two default-mode tests into one
+  table so DRY reports no candidate.
+
+No production behavior changes were needed. The controller structure, injected
+dependencies, and boundaries were accepted.
+
+## Verification results
+
+Record (pinned to the review commit `e4bda31256`):
+
+| File | Component |
+|------|-----------|
+| `docs/reviews/feed-tabs-verification.json` | psf-memo-client |
+
+- **Language mutation** (`mutate-file.sh src/services/feed-tabs-page.js
+  --max-workers 8`, run twice: the differential pass selected 0 changed sites,
+  so the wrapper auto-reran with `--mutate-all`): **22 killed, 0 survived,
+  0 uncovered** (22 total/covered, 0 uncovered).
+- **DRY** (`dry4javascript`, scoped to the changed production files and the
+  changed unit/property tests): **no duplicate candidates found.** The first run
+  flagged one local duplicate in the unit test file (two default-mode tests,
+  score 1.00); removing it cleared the report. A broad whole-client DRY run was
+  not needed and, per standing precedent, its pre-existing step-handler and
+  test-setup boilerplate is not part of this task.
+- **Cyclomatic complexity / CRAP** (`crap4javascript
+  src/services/feed-tabs-page.js`): maximum **CRAP 5.0** at 100% coverage
+  (`open` CC 5); `_isEmptyFollowing`/`_loadMode`/`_normalizeTab` CC 3; every
+  other function CC ≤ 2. All functions are below the 6.0 target.
+- **Soft Gherkin acceptance mutation** (`gherkin-mutator --level soft
+  --workers 8`), `psf-memo-client/specs/feed-tabs.feature`: **42 total,
+  0 killed, 42 survived, 0 errors.** Every survivor is an intrinsic equivalent:
+  a single-character case/character substitution of an example value
+  (`followed_text`, `followed_txid`, `followee`, `other`, `other_text`,
+  `other_txid`) used consistently on both the setup and assertion sides of its
+  scenario, so the scenario still passes. This is the documented behavior for
+  this read-only feature; no implementation gap is implied. `gherkin-mutator`
+  wrote an `acceptance-mutation-manifest` with `"scenarios":[]` (each scenario
+  has an equivalent survivor, so none is recorded) and no `# mutation-stamp`;
+  committed as tool-written.
+
+## Suite status
+
+`verify.sh client` **result: pass** at `git_sha e4bda31256`:
+
+- unit: **506 pass / 0 fail**
+- property: **121 pass / 0 fail**
+- acceptance: **all 37 generated suites passed**
+- lint: ok
+- build: ok
+
+## Handoffs
+
+- End-of-chain `git_handoff` to `specifier` (priority 50) to merge
+  `swarmforge-architect` into `master`, using this records/summary commit.
+- `git_handoff` to `coder` and `refactorer` (priority 00) with the review commit
+  `e4bda31256` for follow-up review: the view now consumes `getState()`, and the
+  default-mode tests were consolidated with added initial-state coverage; the
+  rest is tool-written mutation and acceptance manifests.

docs/reviews/feed-tabs-verification.json

@@ -0,0 +1,46 @@
+{
+  "schema_version": 1,
+  "task": "feed-tabs",
+  "component": "psf-memo-client",
+  "git_sha": "e4bda31256dc8cd125e1ab1442f4f1b19cc4acff",
+  "branch": "swarmforge-architect",
+  "timestamp": "2026-09-20T17:38:07.672Z",
+  "commands": [
+    {
+      "name": "unit",
+      "command": "npm test",
+      "exit": 0,
+      "duration_ms": 6556,
+      "summary": "506 pass / 0 fail"
+    },
+    {
+      "name": "property",
+      "command": "npm run test:property",
+      "exit": 0,
+      "duration_ms": 9620,
+      "summary": "121 pass / 0 fail"
+    },
+    {
+      "name": "acceptance",
+      "command": "npm run test:acceptance",
+      "exit": 0,
+      "duration_ms": 14023,
+      "summary": "all 37 acceptance suites passed"
+    },
+    {
+      "name": "lint",
+      "command": "npm run lint",
+      "exit": 0,
+      "duration_ms": 1736,
+      "summary": "ok"
+    },
+    {
+      "name": "build",
+      "command": "npm run build",
+      "exit": 0,
+      "duration_ms": 48366,
+      "summary": "ok"
+    }
+  ],
+  "result": "pass"
+}