Implement Labrinth Canary API flag (#5531)

apps/frontend/src/composables/featureFlags.ts

@@ -43,6 +43,7 @@ export const DEFAULT_FEATURE_FLAGS = validateValues({
 	hidePreviewBanner: false,
 	i18nDebug: false,
 	showDiscoverProjectButtons: false,
+	labrinthApiCanary: false,
 } as const)
 
 export type FeatureFlag = keyof typeof DEFAULT_FEATURE_FLAGS

apps/frontend/src/composables/fetch.js

@@ -5,6 +5,7 @@
 
 let cachedRateLimitKey = undefined
 let rateLimitKeyPromise = undefined
+const LABRINTH_CANARY_COOKIE = 'labrinth-canary=always'
 
 async function getRateLimitKey(config) {
 	if (config.rateLimitKey) return config.rateLimitKey
@@ -38,6 +39,15 @@ export const useBaseFetch = async (url, options = {}, skipAuth = false) => {
 		options.headers['x-ratelimit-key'] = await getRateLimitKey(config)
 	}
 
+	if (useFeatureFlags().value.labrinthApiCanary) {
+		const existingCookie = options.headers.cookie
+		if (!existingCookie?.split('; ').includes(LABRINTH_CANARY_COOKIE)) {
+			options.headers.cookie = existingCookie
+				? `${existingCookie}; ${LABRINTH_CANARY_COOKIE}`
+				: LABRINTH_CANARY_COOKIE
+		}
+	}
+
 	if (!skipAuth) {
 		const auth = await useAuth()
 

apps/frontend/src/helpers/api.ts

@@ -2,7 +2,9 @@ import {
 	type AbstractFeature,
 	type AuthConfig,
 	AuthFeature,
+	CanaryCookieFeature,
 	CircuitBreakerFeature,
+	LABRINTH_CANARY_COOKIE,
 	NodeAuthFeature,
 	nodeAuthState,
 	NuxtCircuitBreakerStorage,
@@ -28,7 +30,11 @@ export function createModrinthClient(
 	auth: Ref<{ token: string | undefined }>,
 	config: { apiBaseUrl: string; archonBaseUrl: string; rateLimitKey?: string },
 ): NuxtModrinthClient {
+	const flags = useFeatureFlags()
 	const optionalFeatures = [
+		new CanaryCookieFeature({
+			getCookie: () => (flags.value.labrinthApiCanary ? LABRINTH_CANARY_COOKIE : undefined),
+		}) as AbstractFeature,
 		import.meta.dev ? (new VerboseLoggingFeature() as AbstractFeature) : undefined,
 	].filter(Boolean) as AbstractFeature[]
 

apps/frontend/src/middleware/project.global.ts

@@ -25,7 +25,11 @@ export default defineNuxtRouteMiddleware(async (to) => {
 
 	const queryClient = useAppQueryClient()
 	const authToken = useCookie('auth-token')
-	const client = useServerModrinthClient({ authToken: authToken.value || undefined })
+	const flags = useFeatureFlags()
+	const client = useServerModrinthClient({
+		authToken: authToken.value || undefined,
+		canaryCookie: flags.value.labrinthApiCanary,
+	})
 	const tags = useGeneratedState()
 	const projectId = to.params.id as string
 

apps/frontend/src/server/utils/api-client.ts

@@ -1,7 +1,9 @@
 import {
 	type AuthConfig,
 	AuthFeature,
+	CanaryCookieFeature,
 	type FeatureConfig,
+	LABRINTH_CANARY_COOKIE,
 	type NuxtClientConfig,
 	NuxtModrinthClient,
 } from '@modrinth/api-client'
@@ -20,6 +22,7 @@ async function getRateLimitKeyFromSecretsStore(): Promise<string | undefined> {
 export interface ServerModrinthClientOptions {
 	event?: H3Event
 	authToken?: string
+	canaryCookie?: boolean
 }
 
 export function useServerModrinthClient(options?: ServerModrinthClientOptions): NuxtModrinthClient {
@@ -37,6 +40,10 @@ export function useServerModrinthClient(options?: ServerModrinthClientOptions):
 		)
 	}
 
+	if (options?.canaryCookie) {
+		features.push(new CanaryCookieFeature({ getCookie: () => LABRINTH_CANARY_COOKIE }))
+	}
+
 	const clientConfig: NuxtClientConfig = {
 		labrinthBaseUrl: apiBaseUrl,
 		rateLimitKey: config.rateLimitKey || getRateLimitKeyFromSecretsStore,

packages/api-client/src/features/canary-cookie.ts

@@ -0,0 +1,37 @@
+import { AbstractFeature, type FeatureConfig } from '../core/abstract-feature'
+
+export const LABRINTH_CANARY_COOKIE = 'labrinth-canary=always'
+
+export interface CanaryCookieConfig extends FeatureConfig {
+	getCookie?: () => string | undefined | Promise<string | undefined>
+}
+
+export class CanaryCookieFeature extends AbstractFeature {
+	declare protected config: CanaryCookieConfig
+
+	constructor(config?: CanaryCookieConfig) {
+		super(config)
+	}
+
+	shouldApply(context: Parameters<AbstractFeature['shouldApply']>[0]): boolean {
+		return super.shouldApply(context) && context.options.api === 'labrinth'
+	}
+
+	async execute<T>(next: () => Promise<T>, context: Parameters<AbstractFeature['execute']>[1]) {
+		const cookie = this.config.getCookie ? await this.config.getCookie() : LABRINTH_CANARY_COOKIE
+		if (!cookie) {
+			return next()
+		}
+
+		const headers = { ...(context.options.headers ?? {}) }
+		const existingCookie = headers.cookie ?? headers.Cookie
+
+		if (!existingCookie?.split('; ').includes(cookie)) {
+			headers.cookie = existingCookie ? `${existingCookie}; ${cookie}` : cookie
+			delete headers.Cookie
+			context.options.headers = headers
+		}
+
+		return next()
+	}
+}

packages/api-client/src/index.ts

@@ -9,6 +9,11 @@ export {
 } from './core/abstract-websocket'
 export { ModrinthApiError, ModrinthServerError } from './core/errors'
 export { type AuthConfig, AuthFeature } from './features/auth'
+export {
+	type CanaryCookieConfig,
+	CanaryCookieFeature,
+	LABRINTH_CANARY_COOKIE,
+} from './features/canary-cookie'
 export {
 	type CircuitBreakerConfig,
 	CircuitBreakerFeature,