refactor(favicon): eliminate duplicate icon-set map, add getDeploymentEnv() test coverage

Self-review pass, not a review-comment fix:

- app/api/favicon/route.ts maintained its own env-to-svg-path map
  (FAVICON_DESTINATIONS) duplicating ICON_SETS in
  ee/whitelabeling/metadata.ts. The two could silently drift apart if
  an asset path ever changed in only one place. Exported ICON_SETS from
  metadata.ts (and the ee/whitelabeling barrel) and had the route reuse
  it directly instead.

- Added lib/core/config/env-flags.test.ts covering getDeploymentEnv()'s
  resolution chain: each real AWS Secrets Manager value (dev/staging/prod),
  the APPCONFIG_ENVIRONMENT production->prod mapping, the NODE_ENV
  fallback, precedence ordering between the three signals, and an
  unrecognized-value case bucketing safely to development rather than
  throwing. This logic went through three rounds of review fixes: worth
  a regression net now that it's settled.

Author: waleedlatif1

apps/sim/app/api/favicon/route.ts

@@ -1,16 +1,10 @@
 import { type NextRequest, NextResponse } from 'next/server'
 import { getDeploymentEnv } from '@/lib/core/config/env-flags'
 import { withRouteHandler } from '@/lib/core/utils/with-route-handler'
-import { getBrandConfig } from '@/ee/whitelabeling/branding'
+import { getBrandConfig, ICON_SETS } from '@/ee/whitelabeling'
 
 export const dynamic = 'force-dynamic'
 
-const FAVICON_DESTINATIONS: Record<ReturnType<typeof getDeploymentEnv>, string> = {
-  development: '/icon-dev.svg',
-  staging: '/icon-staging.svg',
-  production: '/icon.svg',
-}
-
 /**
  * Redirect target for the legacy `/favicon.ico` path (rewritten here in
  * `next.config.ts`), resolved per-request rather than baked into
@@ -23,12 +17,14 @@ const FAVICON_DESTINATIONS: Record<ReturnType<typeof getDeploymentEnv>, string>
  * that shared build and would freeze whichever tier happened to be active
  * then (never the tier the container actually ends up running as).
  *
- * A whitelabeled deployment's own favicon always wins here too, matching
- * `generateBrandedMetadata()` (`ee/whitelabeling/metadata.ts`) — a tenant on
- * a dev/staging environment should never see Sim's internal tinted mark.
+ * Reuses {@link ICON_SETS} from `ee/whitelabeling/metadata.ts` rather than
+ * maintaining a second env-to-path map here, so the two can't drift apart. A
+ * whitelabeled deployment's own favicon always wins here too, matching
+ * `generateBrandedMetadata()` — a tenant on a dev/staging environment should
+ * never see Sim's internal tinted mark.
  */
 export const GET = withRouteHandler(async (request: NextRequest) => {
   const brand = getBrandConfig()
-  const destination = brand.faviconUrl || FAVICON_DESTINATIONS[getDeploymentEnv()]
+  const destination = brand.faviconUrl || ICON_SETS[getDeploymentEnv()].svg
   return NextResponse.redirect(new URL(destination, request.url))
 })

apps/sim/ee/whitelabeling/index.ts

@@ -2,5 +2,5 @@ export type { OrganizationWhitelabelSettings } from '@/lib/branding/types'
 export type { BrandConfig, ThemeColors } from './branding'
 export { getBrandConfig, useBrandConfig } from './branding'
 export { generateThemeCSS } from './inject-theme'
-export { generateBrandedMetadata, generateStructuredData } from './metadata'
+export { generateBrandedMetadata, generateStructuredData, ICON_SETS } from './metadata'
 export { generateOrgThemeCSS, mergeOrgBrandConfig } from './org-branding-utils'

apps/sim/ee/whitelabeling/metadata.ts

@@ -16,11 +16,12 @@ interface FaviconSet {
  * Same "sim" wordmark per {@link getDeploymentEnv}, background color only —
  * so a dev/staging tab is never mistaken for prod at a glance. Ignored
  * entirely when `brand.faviconUrl` is set (a whitelabeled deployment's own
- * favicon always wins, regardless of which tier it's running on). Kept in
- * sync with `FAVICON_ICO_DESTINATIONS` in `next.config.ts`, which handles
- * the legacy `/favicon.ico` path the same way.
+ * favicon always wins, regardless of which tier it's running on). Exported
+ * for `app/api/favicon/route.ts` (the legacy `/favicon.ico` redirect target)
+ * to reuse `.svg` from, so the two never drift out of sync the way two
+ * separately-maintained copies could.
  */
-const ICON_SETS: Record<ReturnType<typeof getDeploymentEnv>, FaviconSet> = {
+export const ICON_SETS: Record<ReturnType<typeof getDeploymentEnv>, FaviconSet> = {
   development: {
     svg: '/icon-dev.svg',
     favicon16: '/favicon-dev/favicon-16x16.png',

apps/sim/lib/core/config/env-flags.test.ts

@@ -0,0 +1,78 @@
+/**
+ * @vitest-environment node
+ */
+import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest'
+
+const { envRef } = vi.hoisted(() => ({
+  envRef: { NODE_ENV: 'development' as string | undefined },
+}))
+
+vi.mock('@/lib/core/config/env', () => ({
+  get env() {
+    return envRef
+  },
+  getEnv: (key: string) => process.env[key],
+  isFalsy: (v: unknown) => v === false || v === 'false' || v === '0',
+  isTruthy: (v: unknown) => v === true || v === 'true' || v === '1',
+}))
+
+import { getDeploymentEnv } from '@/lib/core/config/env-flags'
+
+describe('getDeploymentEnv', () => {
+  const ENV_KEYS = [
+    'OTEL_DEPLOYMENT_ENVIRONMENT',
+    'DEPLOYMENT_ENVIRONMENT',
+    'APPCONFIG_ENVIRONMENT',
+  ]
+
+  beforeEach(() => {
+    for (const key of ENV_KEYS) delete process.env[key]
+    envRef.NODE_ENV = 'development'
+  })
+
+  afterEach(() => {
+    for (const key of ENV_KEYS) delete process.env[key]
+  })
+
+  it('resolves the dev tier from OTEL_DEPLOYMENT_ENVIRONMENT=dev', () => {
+    process.env.OTEL_DEPLOYMENT_ENVIRONMENT = 'dev'
+    expect(getDeploymentEnv()).toBe('development')
+  })
+
+  it('resolves the staging tier from OTEL_DEPLOYMENT_ENVIRONMENT=staging', () => {
+    process.env.OTEL_DEPLOYMENT_ENVIRONMENT = 'staging'
+    expect(getDeploymentEnv()).toBe('staging')
+  })
+
+  it('resolves the production tier from OTEL_DEPLOYMENT_ENVIRONMENT=prod', () => {
+    process.env.OTEL_DEPLOYMENT_ENVIRONMENT = 'prod'
+    expect(getDeploymentEnv()).toBe('production')
+  })
+
+  it('maps APPCONFIG_ENVIRONMENT=production to the production tier when OTEL var is unset', () => {
+    process.env.APPCONFIG_ENVIRONMENT = 'production'
+    expect(getDeploymentEnv()).toBe('production')
+  })
+
+  it('falls back to NODE_ENV when no deployment-tier env var is set', () => {
+    envRef.NODE_ENV = 'production'
+    expect(getDeploymentEnv()).toBe('production')
+  })
+
+  it('defaults to development when nothing is set at all', () => {
+    envRef.NODE_ENV = undefined
+    expect(getDeploymentEnv()).toBe('development')
+  })
+
+  it('prefers OTEL_DEPLOYMENT_ENVIRONMENT over DEPLOYMENT_ENVIRONMENT and APPCONFIG_ENVIRONMENT', () => {
+    process.env.OTEL_DEPLOYMENT_ENVIRONMENT = 'staging'
+    process.env.DEPLOYMENT_ENVIRONMENT = 'prod'
+    process.env.APPCONFIG_ENVIRONMENT = 'production'
+    expect(getDeploymentEnv()).toBe('staging')
+  })
+
+  it('buckets an unrecognized tier value to development rather than throwing', () => {
+    process.env.OTEL_DEPLOYMENT_ENVIRONMENT = 'some-future-tier'
+    expect(getDeploymentEnv()).toBe('development')
+  })
+})