flynn/.planning/phases/02-config-overlays/02-VERIFICATION.md

phase, verified, status, score, re_verification

phase	verified	status	score	re_verification
02-config-overlays	2026-02-09T21:05:00Z	passed	8/8 must-haves verified	false

Phase 2: Config Overlays Verification Report

Phase Goal: Operator can manage dev/docker/production configs with a base file plus lightweight overlay files, selected by environment variable. Verified: 2026-02-09T21:05:00Z Status: passed Re-verification: No — initial verification

Goal Achievement

Observable Truths

#	Truth	Status	Evidence
1	Setting FLYNN_ENV=docker loads docker.yaml overlay merged on top of base config	✓ VERIFIED	loadConfigSafe in shared.ts (L33-34) calls resolveOverlayPath then passes result to loadConfig(path, overlayPath). loadConfig in loader.ts (L72-81) reads overlay, calls deepMerge before validation. Test "merges overlay on top of base config" (loader.test.ts L116-141) proves port override + base token retention.
2	Starting Flynn without FLYNN_ENV works exactly as before — zero breakage	✓ VERIFIED	resolveOverlayPath returns undefined when FLYNN_ENV not set (shared.ts L23-24). loadConfig skips overlay when overlayPath is falsy (loader.ts L72). Test "loads base-only when no overlay provided" (loader.test.ts L143-162) proves backward compatibility. 13/13 loader tests pass.
3	Overlay values override base values at any nesting depth	✓ VERIFIED	deepMerge recursively merges plain objects (loader.ts L42-61). Test "handles deeply nested objects (3+ levels)" (loader.test.ts L28-33) proves 3+ level override.
4	Overlay files do not need to repeat required base fields — merge before Zod validation	✓ VERIFIED	Merge at loader.ts L76, then env expansion at L83, then configSchema.parse at L84. Overlay test uses partial YAML (only server.port) without telegram/models — passes validation.
5	Arrays in overlays replace base arrays (not concatenated)	✓ VERIFIED	deepMerge explicitly checks Array.isArray and falls through to direct assignment (loader.ts L47,50,57). Test "overlay arrays replace base arrays" (loader.test.ts L13-16) proves [1,2] → [3].
6	Running flynn doctor with FLYNN_ENV=staging (no staging.yaml) reports clear error identifying missing overlay	✓ VERIFIED	checkOverlayExists in doctor.ts (L30-39) calls resolveOverlayPath, checks existsSync, returns fail with FLYNN_ENV=${env} but ${overlayPath} not found. Wired in allChecks array at position 2 (L218).
7	Running flynn doctor without FLYNN_ENV shows no overlay-related error	✓ VERIFIED	checkOverlayExists returns { status: 'skip', label: 'Config overlay', detail: '(FLYNN_ENV not set)' } when resolveOverlayPath returns undefined (doctor.ts L32-33).
8	Running flynn doctor with FLYNN_ENV=docker and docker.yaml present shows overlay check passing	✓ VERIFIED	checkOverlayExists returns { status: 'pass', label: 'Config overlay', detail: '(${env}.yaml found)' } when file exists (doctor.ts L36-37).

Score: 8/8 truths verified

Required Artifacts

Artifact	Expected	Status	Details
src/config/loader.ts	deepMerge utility + overlay-aware loadConfig	✓ VERIFIED	86 lines. Exports deepMerge (L38) and loadConfig with optional overlayPath (L68). Merge before env expansion and Zod parse.
src/config/loader.test.ts	Tests for deep merge, overlay loading, backward compat, missing overlay	✓ VERIFIED	210 lines. 13 tests total: 6 deepMerge unit tests + 4 overlay integration tests + 3 original tests. All 13 pass.
src/cli/shared.ts	resolveOverlayPath + overlay-aware loadConfigSafe	✓ VERIFIED	81 lines. resolveOverlayPath (L22-27) maps FLYNN_ENV to sibling yaml. loadConfigSafe (L30-39) passes overlay to loadConfig.
src/config/index.ts	Re-exports deepMerge	✓ VERIFIED	Line 1: export { loadConfig, deepMerge } from './loader.js';
src/cli/doctor.ts	checkOverlayExists doctor check	✓ VERIFIED	checkOverlayExists (L30-39) with skip/pass/fail tristate. Positioned in allChecks after checkConfigExists, before checkConfigParses (L216-218).

Key Link Verification

From	To	Via	Status	Details
src/cli/shared.ts	src/config/loader.ts	loadConfigSafe calls loadConfig(path, overlayPath)	✓ WIRED	shared.ts L34: const config = loadConfig(path, overlayPath);
src/config/loader.ts	src/config/loader.ts	loadConfig calls deepMerge before configSchema.parse	✓ WIRED	loader.ts L76: rawConfig = deepMerge(...) then L84: configSchema.parse(expandedConfig)
src/cli/doctor.ts	src/cli/shared.ts	imports resolveOverlayPath	✓ WIRED	doctor.ts L3: import { ..., resolveOverlayPath } from './shared.js'; L31: resolveOverlayPath(ctx.configPath)
src/cli/start.ts	src/cli/shared.ts	loadConfigSafe (overlay-aware)	✓ WIRED	start.ts L2: import { loadConfigSafe } from './shared.js'; L22: loadConfigSafe(configPath) — daemon gets merged config automatically
src/config/index.ts	src/config/loader.ts	Re-exports deepMerge	✓ WIRED	index.ts L1: export { loadConfig, deepMerge } from './loader.js';

Requirements Coverage

Requirement	Status	Details
CONF-01: User can set FLYNN_ENV to select config overlay	✓ SATISFIED	resolveOverlayPath reads process.env.FLYNN_ENV, maps to {configDir}/{env}.yaml. All CLI entry points use loadConfigSafe which calls this.
CONF-02: Config loader merges env-specific overlay on top of base with deep merge	✓ SATISFIED	deepMerge in loader.ts recursively merges objects. loadConfig applies overlay before env expansion and Zod validation. 10 tests prove behavior.
CONF-03: flynn doctor validates overlay file exists when FLYNN_ENV is set	✓ SATISFIED	checkOverlayExists in doctor.ts checks file existence with clear error: FLYNN_ENV=${env} but ${overlayPath} not found. Skips when FLYNN_ENV not set.

Anti-Patterns Found

File	Line	Pattern	Severity	Impact
—	—	—	—	None found

No TODOs, FIXMEs, placeholders, empty implementations, or console.log-only handlers found in any phase files.

Human Verification Required

1. Overlay Loading End-to-End

Test: Create ~/.config/flynn/docker.yaml with server: { port: 9999 }, run FLYNN_ENV=docker flynn start, verify port changes in daemon output. Expected: Daemon starts on port 9999 instead of default, with all other config intact from base. Why human: Requires running the actual daemon and observing startup behavior.

2. Doctor Missing Overlay Output

Test: Run FLYNN_ENV=staging flynn doctor without creating staging.yaml. Expected: Output shows [FAIL] Config overlay FLYNN_ENV=staging but /path/to/staging.yaml not found. Why human: Verifying exact terminal output formatting and exit code.

3. Doctor No-Overlay Output

Test: Run flynn doctor without FLYNN_ENV set. Expected: Output shows [SKIP] Config overlay (FLYNN_ENV not set) — no errors, no noise. Why human: Verifying visual output and that it doesn't confuse operators.

Gaps Summary

No gaps found. All observable truths are verified with code evidence and passing tests. All artifacts exist, are substantive (not stubs), and are fully wired into the application. The three success criteria from the phase goal are all satisfied:

1. FLYNN_ENV=docker loading — resolveOverlayPath + loadConfig(base, overlay) + deepMerge before Zod validation. Tested.
2. No FLYNN_ENV = same behavior — resolveOverlayPath returns undefined, loadConfig skips overlay path. Tested.
3. Doctor reports missing overlay — checkOverlayExists with fail status and descriptive message. Wired in allChecks array.

TypeScript type checking passes clean. All 13 loader tests pass. No anti-patterns detected.

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Verified: 2026-02-09T21:05:00Z Verifier: Claude (gsd-verifier)