psf-memo-client/docs/reviews/like-tip-memo-summary.md

# Architectural Review Summary — like-tip-memo

## Task and commits reviewed
- Task: `like-tip-memo`
- Processed the refactorer handoff `merge_and_process refactorer 6b7a7e2b86` and
  fast-forward merged the `swarmforge-refactorer` branch ending at `6b7a7e2b86`
  into `swarmforge-architect`, which carried:
  - `eb9aa29` — specifier: added `specs/like-tip-memo.feature` (10 scenarios) and
    `dev-docs/psf-memo-db-changes.md`
  - `dd0535d` — coder: implemented the Memo like action (`0x6d04`) with optional
    author tip, the like/tip page controller, heart-icon + modal UI, and acceptance
    handlers
  - `6b7a7e2b86` — refactorer: reduced CRAP in the like/tip slice, consolidated
    rejection assertions, and added hex/like/property tests

## Architectural findings and fixes applied
Reviewed UI/Core separation, dependency rule, information hiding/encapsulation, and
local code quality.

1. **UI/Core separation (good).** Core behavior is cleanly split from UI:
   - `src/services/memo-like.js` (extends `MemoAction`) owns compose/validate/broadcast
     of the like OP_RETURN and optional tip, speaking only to an injected wallet.
   - `src/services/like-tip-page.js` (extends `PageController`) owns the modal page
     behavior (open/close/setTip/submit and error classification).
   - React (`like-button.js`, `like-tip-modal.js`, `post-feed-item.js`) is a thin shell
     over the testable services. Core is testable with no UI/IO.
2. **Dependency rule (good).** UI components depend inward on services;
   `LikeTipPage` → `MemoLike` → `MemoAction`. Wallet/network I/O stays behind the
   injected minimal-slp-wallet adapter. No low-level module reaches toward IO.
3. **Information hiding / encapsulation (good).** Txid hex encoding, tip validation
   (integer, dust floor, hard max, spendable balance), and the `0x6d04` wire prefix
   are encapsulated. `hexToBytes` was extracted to `src/services/hex.js` and is shared
   with `memo-reply.js` — a good cross-slice DRY consolidation.
4. **Local code quality (good).** Small, single-responsibility modules; CRAP for every
   like/tip function is at or below 6 with 100% coverage.
5. **Boundary test gap closed (architect fix).** Added three boundary unit tests to
   `test/unit/memo-like.test.js`:
   - a tip at exactly the hard maximum is accepted,
   - a wallet with exactly the dust-limit balance can make a pure like,
   - a tip at exactly the spendable balance is accepted.
   These kill the previously-surviving `> -> >=` / `< -> <=` boundary mutants and pin
   down the inclusive max/balance semantics.

## Verification results
- **Unit (`node --test`):** 133/133 pass (including the 3 added boundary tests).
- **Property (`node --test test/property/*.test.js`):** 18/18 pass.
- **Acceptance (normal):** `memo-new`, `post-memo`, `set-name`, `reply-memo`, and
  `like-tip-memo` (10 scenarios) generated suites all pass.
- **Mutation (`mutate4javascript src/services/memo-like.js --mutate-all`):**
  25 killed, 0 uncovered, **7 survived — all documented equivalents**:
  - `validate` / `validateTip` `{ok:true}` returns are ignored by `like()` (dead
    return value),
  - `like` default `tipSats = 0` (callers always pass the parsed tip),
  - `_requireTipAddress` / `_buildTipOutput` boundary mutations on `tipSats ≤ 1` /
    `authorAddress.length > 1` are unreachable because such tips are below the dust
    floor and rejected earlier.
- **DRY (`dry4javascript src/services/memo-like.js like-tip-page.js hex.js`):** no
  duplicate candidates.
- **Gherkin acceptance mutation (soft) on `like-tip-memo.feature`:** 16 executed,
  **4 killed, 12 survived**, 0 errors. Every survivor is an expected soft survival:
  a mutated example value still yields the same asserted outcome (a still-invalid tip,
  a still-below-dust tip, or a tip/balance pair that still trips the same check).
- **CRAP:** all like/tip functions ≤ 6.0 (max `_validateTipAmount` 6.0), 100% coverage.

## Suite status
Unit + property + acceptance all pass; source-level mutation kills all meaningful
mutants with survivors documented as equivalents; DRY clean; CRAP within threshold.

## Handoffs sent
- `git_handoff` → coder, refactorer (priority `00`, task `like-tip-memo`), to review
  the architect commit (three boundary tests + tool-refreshed manifests; no source
  logic change).
- No handoff to the specifier: the architect produced no functional feature commit.

By architect.