feat(ADM-018): completed feature

legacy/specs-old/F-004-config-flags/TESTS.md

@@ -0,0 +1,22 @@
+# TESTS — F-004 Typed config and feature flags
+
+## Unit — src/infrastructure/config/tests/config.test.ts
+1. Valid full env -> typed AppConfig (port number, nodeEnv enum, flags parsed)
+2. Missing DATABASE_URL -> ConfigError naming DATABASE_URL
+3. Invalid PORT (non-numeric / out of range) -> ConfigError naming PORT
+4. Invalid NODE_ENV -> ConfigError
+5. FLAG_* true/false parsed; unknown flag value -> ConfigError naming the var
+6. Multiple problems -> single ConfigError listing all of them
+
+## Unit — src/modules/flags/tests/feature-flag-store.test.ts
+1. Known flag on -> isEnabled true; known flag off -> false
+2. Unknown flag -> false (fail-safe)
+3. setEnabled flips state at runtime (no new store / no redeploy)
+4. createFlagStore seeds initial state
+
+## Composition
+5. buildApp with flags dep: guarded path skipped when flag off, runs when on
+
+## Manual / QA
+- Start server without DATABASE_URL -> clear error naming the var, non-zero exit.
+- verify.sh green.