Modify router-worker logic to allow for running user-worker ahead of …

…assets (#7303)

- Adds logic to run user-worker ahead of assets
- Moves vitest from worker-shared root into asset-worker
- Creates new vitest unit suite for router-worker

.changeset/funny-dingos-guess.md

@@ -0,0 +1,5 @@
+---
+"@cloudflare/workers-shared": minor
+---
+
+Option to invoke user worker ahead of assets

packages/workers-shared/vitest.config.mts → packages/workers-shared/asset-worker/vitest.config.mts

@@ -1,11 +1,11 @@
 import { defineProject, mergeConfig } from "vitest/config";
-import configShared from "../../vitest.shared";
+import configShared from "../../../vitest.shared.js";
 
 export default mergeConfig(
 	configShared,
 	defineProject({
 		test: {
-			include: ["asset-worker/tests/**.{test,spec}.{ts,js}"],
+			include: ["tests/**.{test,spec}.{ts,js}"],
 			globals: true,
 		},
 	})

packages/workers-shared/asset-worker/wrangler.toml

@@ -12,6 +12,7 @@ account_id = "0f1b8aa119a907021f659042f95ea9ba"
 workers_dev = false
 main = "src/index.ts"
 compatibility_date = "2024-07-31"
+# nodejs_compat required when using @cloudflare/vitest-pool-workers
 compatibility_flags = ["nodejs_compat"]
 
 [[unsafe.bindings]]

packages/workers-shared/package.json

@@ -30,14 +30,16 @@
 		"bundle:router-worker:prod": "pnpm run bundle:router-worker --minify",
 		"check:lint": "eslint . --max-warnings=0",
 		"check:type": "pnpm run check:type:tests && tsc",
-		"check:type:tests": "tsc -p ./asset-worker/tests/tsconfig.json",
+		"check:type:tests": "tsc -p ./asset-worker/tests/tsconfig.json && tsc -p ./router-worker/tests/tsconfig.json",
 		"clean": "rimraf dist",
 		"deploy": "pnpm run deploy:router-worker && pnpm run deploy:asset-worker",
 		"deploy:asset-worker": "CLOUDFLARE_API_TOKEN=$WORKERS_DEPLOY_AND_CONFIG_CLOUDFLARE_API_TOKEN pnpx wrangler versions upload --experimental-versions -c asset-worker/wrangler.toml",
 		"deploy:router-worker": "CLOUDFLARE_API_TOKEN=$WORKERS_DEPLOY_AND_CONFIG_CLOUDFLARE_API_TOKEN pnpx wrangler versions upload --experimental-versions -c router-worker/wrangler.toml",
 		"dev": "pnpm run clean && concurrently -n bundle:asset-worker,bundle:router-worker -c blue,magenta \"pnpm run bundle:asset-worker --watch\" \"pnpm run bundle:router-worker --watch\"",
-		"test": "vitest",
-		"test:ci": "vitest run",
+		"test": "concurrently --group -n router-worker,asset-worker \"pnpm run test:router-worker\" \"pnpm run test:asset-worker\"",
+		"test:asset-worker": "vitest -c asset-worker/vitest.config.mts --dir asset-worker",
+		"test:ci": "pnpm run test",
+		"test:router-worker": "vitest -c router-worker/vitest.config.mts --dir router-worker",
 		"types:emit": "tsc index.ts --declaration --emitDeclarationOnly --declarationDir ./dist"
 	},
 	"dependencies": {
@@ -46,6 +48,7 @@
 	},
 	"devDependencies": {
 		"@cloudflare/eslint-config-worker": "workspace:*",
+		"@cloudflare/vitest-pool-workers": "latest",
 		"@cloudflare/workers-tsconfig": "workspace:*",
 		"@cloudflare/workers-types": "^4.20241106.0",
 		"@types/mime": "^3.0.4",

packages/workers-shared/router-worker/src/index.ts

@@ -56,6 +56,19 @@ export default {
 			}
 
 			const maybeSecondRequest = request.clone();
+
+			// User's configuration indicates they want user-Worker to run ahead of any
+			// assets. Do not provide any fallback logic.
+			if (env.CONFIG.invoke_user_worker_ahead_of_assets) {
+				if (!env.CONFIG.has_user_worker) {
+					throw new Error(
+						"Fetch for user worker without having a user worker binding"
+					);
+				}
+				return env.USER_WORKER.fetch(maybeSecondRequest);
+			}
+
+			// Otherwise, we try to first fetch assets, falling back to user-Worker.
 			if (env.CONFIG.has_user_worker) {
 				if (await env.ASSET_WORKER.unstable_canFetch(request)) {
 					analytics.setData({ dispatchtype: DISPATCH_TYPE.ASSETS });

packages/workers-shared/router-worker/tests/index.test.ts

@@ -0,0 +1,74 @@
+import { createExecutionContext } from "cloudflare:test";
+import { describe, expect, it } from "vitest";
+import { default as worker } from "../src/index";
+
+describe("unit tests", async () => {
+	it("fails if specify running user worker ahead of assets, without user worker", async () => {
+		const request = new Request("https://example.com");
+		const ctx = createExecutionContext();
+
+		const env = {
+			CONFIG: {
+				invoke_user_worker_ahead_of_assets: true,
+				has_user_worker: false,
+			},
+		} as typeof env;
+
+		void expect(
+			async () => await worker.fetch(request, env, ctx)
+		).rejects.toThrowError(
+			"Fetch for user worker without having a user worker binding"
+		);
+	});
+
+	it("it returns fetch from user worker when invoke_user_worker_ahead_of_assets true", async () => {
+		const request = new Request("https://example.com");
+		const ctx = createExecutionContext();
+
+		const env = {
+			CONFIG: {
+				invoke_user_worker_ahead_of_assets: true,
+				has_user_worker: true,
+			},
+			USER_WORKER: {
+				async fetch(_: Request): Promise<Response> {
+					return new Response("hello from user worker");
+				},
+			},
+			ASSET_WORKER: {
+				async fetch(_: Request): Promise<Response> {
+					return new Response("hello from asset worker");
+				},
+				async unstable_canFetch(_: Request): Promise<boolean> {
+					return true;
+				},
+			},
+		} as typeof env;
+
+		const response = await worker.fetch(request, env, ctx);
+		expect(await response.text()).toEqual("hello from user worker");
+	});
+
+	it("it returns fetch from asset worker when matching existing asset path", async () => {
+		const request = new Request("https://example.com");
+		const ctx = createExecutionContext();
+
+		const env = {
+			CONFIG: {
+				invoke_user_worker_ahead_of_assets: false,
+				has_user_worker: false,
+			},
+			ASSET_WORKER: {
+				async fetch(_: Request): Promise<Response> {
+					return new Response("hello from asset worker");
+				},
+				async unstable_canFetch(_: Request): Promise<boolean> {
+					return true;
+				},
+			},
+		} as typeof env;
+
+		const response = await worker.fetch(request, env, ctx);
+		expect(await response.text()).toEqual("hello from asset worker");
+	});
+});

packages/workers-shared/router-worker/tests/tsconfig.json

@@ -0,0 +1,15 @@
+{
+	"compilerOptions": {
+		"target": "ES2020",
+		"module": "ES2020",
+		"lib": ["ES2020"],
+		"types": [
+			"@cloudflare/workers-types/experimental",
+			"@cloudflare/vitest-pool-workers"
+		],
+		"moduleResolution": "bundler",
+		"noEmit": true,
+		"skipLibCheck": true
+	},
+	"include": ["**/*.ts"]
+}

packages/workers-shared/router-worker/vitest.config.mts

@@ -0,0 +1,13 @@
+import { defineWorkersConfig } from "@cloudflare/vitest-pool-workers/config";
+
+export default defineWorkersConfig({
+	test: {
+		poolOptions: {
+			workers: {
+				wrangler: {
+					configPath: "./wrangler.toml",
+				},
+			},
+		},
+	},
+});

packages/workers-shared/router-worker/wrangler.toml

@@ -12,6 +12,8 @@ account_id = "0f1b8aa119a907021f659042f95ea9ba"
 workers_dev = false
 main = "src/index.ts"
 compatibility_date = "2024-07-31"
+# nodejs_compat required when using @cloudflare/vitest-pool-workers
+compatibility_flags = ["nodejs_compat", "no_nodejs_compat_v2"]
 
 [version_metadata]
 binding = "VERSION_METADATA"

packages/workers-shared/tsconfig.json

@@ -5,7 +5,7 @@
 		"sourceMap": true,
 		"forceConsistentCasingInFileNames": true,
 		"useUnknownInCatchVariables": false,
-		"types": ["@cloudflare/workers-types/experimental"]
+		"types": ["@cloudflare/workers-types/experimental", "@types/node"]
 	},
 	"include": ["**/*.ts", "vitest.config.mts"],
 	"exclude": ["node_modules", "dist", "**/tests", "**/*.test.ts"]

packages/workers-shared/utils/types.ts

@@ -2,6 +2,7 @@ import { z } from "zod";
 
 export const RoutingConfigSchema = z.object({
 	has_user_worker: z.boolean().optional(),
+	invoke_user_worker_ahead_of_assets: z.boolean().optional(),
 });
 
 export const AssetConfigSchema = z.object({