---
phase: 17-mimecast-blast-radius-lookup
verified: 2026-07-15T14:35:00Z
status: passed
score: 5/5 must-haves verified
overrides_applied: 0
---

# Phase 17: Mimecast Blast Radius Lookup Verification Report

**Phase Goal:** Pulse can ask "how far did this message spread" via a Mimecast blast-radius abstraction when Mimecast is configured, and gets a clean `unavailable` signal — never a crash or a block — when it isn't.
**Verified:** 2026-07-15T14:35:00Z
**Status:** passed
**Re-verification:** No — initial verification

## Goal Achievement

### Observable Truths

| # | Truth | Status | Evidence |
|---|-------|--------|----------|
| 1 | `isMimecastConfigured()` returns true only when both `MIMECAST_CLIENT_ID` and `MIMECAST_CLIENT_SECRET` are set, false otherwise | VERIFIED | `lib/services/mimecast-client.ts:647-649` — `!!(process.env.MIMECAST_CLIENT_ID && process.env.MIMECAST_CLIENT_SECRET)`. Tested in `mimecast-client.test.ts` (4 cases: neither/only-ID/only-secret/both), all pass. |
| 2 | `getBlastRadius()` returns `status:'unavailable' reason:'not_configured'` synchronously (no Mimecast call) when unconfigured | VERIFIED | `mimecast-blast-radius.ts:92-95` returns before any client construction. Test asserts `getMimecastClientMock`/all 3 fan-out mocks `.not.toHaveBeenCalled()`. |
| 3 | `getBlastRadius()` when configured returns normalized matched/delivered/held/rejected/clicked counts + per-recipient status array, built by fanning out to `searchDeliveredMessages` + `getHeldMessages` + `getThreatEvents` UNCONDITIONALLY (not gated behind a `getMessageInfo` miss — corrected D-01 / Pitfall 1) | VERIFIED | `mimecast-blast-radius.ts:104-128` — `getMessageInfo` (line 109-111) is called only for supplementary body/header evidence when `messageId` present, its result is discarded (not awaited into a variable used downstream), and is NOT inside any conditional that gates the `Promise.all([...])` fan-out at line 118, which always runs. Merge logic at 130-184 builds real counts, not fallback zeros. Test "merges delivered/held/threat-event fixtures..." confirms counts (`matched:2, delivered:1, held:1, rejected:1, clicked:1`) and `perRecipient` array. |
| 4 | An unexpected error thrown during the fan-out degrades to `status:'unavailable' reason:'lookup_failed'` rather than propagating | VERIFIED | `mimecast-blast-radius.ts:188-194` catch block. Test "degrades to unavailable/lookup_failed (never throws) when a fan-out call rejects" — `getHeldMessagesMock.mockRejectedValue(...)`, asserts resolved (not rejected) result equals `{status:'unavailable', reason:'lookup_failed', error:'Mimecast API timeout'}`. |
| 5 | A repeated lookup for the same message identity within the cache TTL returns the cached result without re-calling any MimecastClient method | VERIFIED | `mimecast-blast-radius.ts:101-102` — `getCachedData` checked and returned BEFORE `getMimecastClient()` is called at line 105. Test "returns the cached result on a cache hit..." asserts all 3 fan-out mocks and `setCachedDataMock` not called. |

**Score:** 5/5 truths verified

### Required Artifacts

| Artifact | Expected | Status | Details |
|----------|----------|--------|---------|
| `lib/services/mimecast-client.ts` | `isMimecastConfigured()` + `_resetMimecastClient()` config gate / test seam, existing exports untouched | VERIFIED | Lines 647-649 (`isMimecastConfigured`), 651-655 (`_resetMimecastClient`) added directly above unmodified `getMimecastClient()` (657-672) and `getMimecastClientForTenant()` (674+). |
| `lib/services/mimecast-blast-radius.ts` | `getBlastRadius()` orchestration + `BlastRadiusInput`/`BlastRadiusResult` types | VERIFIED | 195 lines; exports `getBlastRadius`, `BlastRadiusInput`, `BlastRadiusResult` (discriminated union) exactly as specced. |
| `lib/services/mimecast-client.test.ts` | Unit tests for `isMimecastConfigured()` + `getMimecastClient()` throw/cache behavior | VERIFIED | 63 lines, 7 tests, all pass (`npx vitest run` confirmed). |
| `lib/services/mimecast-blast-radius.test.ts` | Unit tests for config gate, fan-out merge, never-throw, cache-hit | VERIFIED | 227 lines, 6 tests, all pass. |

### Key Link Verification

| From | To | Via | Status | Details |
|------|----|----|--------|---------|
| `mimecast-blast-radius.ts` | `mimecast-client.ts` | `import { isMimecastConfigured, getMimecastClient, type MimecastDeliveredMessage, type MimecastHeldMessage } from './mimecast-client'` | WIRED | Import present (line 37-42); both interface types confirmed exported from `mimecast-client.ts` (lines 52, 76, 92 — `MimecastThreatEvent`, `MimecastHeldMessage`, `MimecastDeliveredMessage`). |
| `mimecast-blast-radius.ts` | `redis-client.ts` | `import { getCachedData, setCachedData } from './redis-client'` | WIRED | Import present (line 43); both functions called and awaited correctly (cache-check before client construction, cache-write after successful merge only). |

### D-05 Multi-Tenant Comment Verification

`grep -qi "D-05" lib/services/mimecast-blast-radius.ts` → present. The module doc-comment (lines 25-34) explicitly states: "KNOWN LIMITATION — MULTI-TENANT GAP (D-05): this module uses only the single global env-var-configured getMimecastClient(), NOT the per-company `mimecast_tenants` table / getMimecastClientForTenant(). Reports belonging to companies with their own registered Mimecast tenant ... will return `status: 'unavailable'`..." This is a genuine code comment in the shipped file, not just a plan/summary claim.

### Pitfall-Avoidance Verification (17-RESEARCH.md's 3 documented pitfalls)

| Pitfall | Research Concern | Shipped-Code Verification |
|---------|------------------|---------------------------|
| #1 — `getMessageInfo()` has no status/counts; fan-out must be unconditional, not gated on a miss | Implementer might skip fan-out when `getMessageInfo` hits | Confirmed avoided: `getMessageInfo` call (line 110) is a bare `await` whose return value is discarded; the `Promise.all` fan-out (lines 118-128) is unconditional — no `if` branch separates "exact match" from "fallback." Code comment at line 107-108 explicitly documents why. |
| #2 — `getThreatEvents()` click derivation is best-effort, not confirmed-zero | Risk of overstating confidence in `clicked: 0` | Confirmed avoided: doc-comment (b) at lines 17-23 states `clicked: 0` means "no click-type threat event found... NOT confirmed zero clicks." `isClickEvent()` helper (line 88-90) comment references D-02 explicitly. |
| #3 — Multi-tenant gap silently missed | Risk of a silent single-tenant assumption | Confirmed avoided: D-05 comment present and specific (see above); T-17-03 in the plan's threat model documents the accepted risk; not touched by this phase per explicit scope. |

### Requirements Coverage

| Requirement | Source Plan | Description | Status | Evidence |
|-------------|-------------|-------------|--------|----------|
| BLAST-01 | 17-01-PLAN.md | Query blast-radius abstraction for delivery data when configured, keyed on message ID/sender/recipient/subject/date-window | SATISFIED | `getBlastRadius()` implemented and tested per Truth #3 above; ROADMAP.md and REQUIREMENTS.md both mark BLAST-01 `[x]`/`Complete`. |
| BLAST-02 | 17-01-PLAN.md | Not configured → `status: unavailable`, never blocks; unexpected error also degrades | SATISFIED | Truths #2 and #4 above; both paths tested with explicit call-count/rejection assertions. |

No orphaned requirements found for Phase 17 in REQUIREMENTS.md (only BLAST-01/BLAST-02 map to this phase).

### Anti-Patterns Found

None. Scanned all 4 phase-modified/created files (`mimecast-client.ts` diff region, `mimecast-blast-radius.ts`, `mimecast-blast-radius.test.ts`, `mimecast-client.test.ts`) for `TBD|FIXME|XXX|TODO|HACK|PLACEHOLDER|placeholder|not yet implemented` — zero matches.

### Behavioral Spot-Checks

| Behavior | Command | Result | Status |
|----------|---------|--------|--------|
| New unit tests pass in isolation | `npx vitest run lib/services/mimecast-blast-radius.test.ts lib/services/mimecast-client.test.ts` | 2 files, 13 tests, all passed | PASS |
| Type-check clean | `npx tsc --noEmit --pretty` | No output / exit 0 | PASS |
| Full suite has no new regressions | `npm test` | 27 passed / 1 failed file (`itglue-search.test.ts`, 2 tests) — confirmed pre-existing via `git log` (`a0a6e7f`, predates this phase's commits `8b032c3`/`efbc437`) and unrelated to any file this phase touched | PASS (pre-existing failure correctly excluded per task instructions) |

### Test Isolation / Mocking Verification

Both test files declare `vi.mock('./mimecast-client', ...)` / `vi.mock('./redis-client', ...)` (blast-radius test) and import the real `mimecast-client.ts` module only for the config-gate/factory tests (which intentionally exercise the real singleton with env-var manipulation and `_resetMimecastClient()` — no network egress since `getMimecastClient()` only constructs the object, doesn't call out). No `MIMECAST_CLIENT_ID`/`MIMECAST_CLIENT_SECRET` real credentials are referenced; no live HTTP calls are made in either test file (confirmed by reading both files in full — no `fetch`/`request`/network imports present). Redis is fully mocked (`getCachedDataMock`/`setCachedDataMock`).

### Human Verification Required

None. This phase produces no UI, no HTTP route, and no externally-observable runtime behavior beyond the unit-testable function contract — all Success Criteria are objectively verifiable via code + tests.

### Gaps Summary

No gaps found. All 5 derived truths verified, both roadmap Success Criteria requirements (BLAST-01, BLAST-02) satisfied, all 3 documented research pitfalls confirmed avoided in the shipped code (not just claimed in SUMMARY.md), D-05 comment confirmed present in the actual file, cache-short-circuit-before-client-call confirmed via call-count assertions, and the full test suite has zero new regressions (the 2 failing `itglue-search.test.ts` tests are confirmed pre-existing and unrelated).

---

*Verified: 2026-07-15T14:35:00Z*
*Verifier: Claude (gsd-verifier)*
