Stabilise Worker Loader binding

.changeset/witty-ideas-rhyme.md

@@ -0,0 +1,5 @@
+---
+"wrangler": minor
+---
+
+Stabilise Worker Loader bindings

fixtures/dynamic-worker-loading/wrangler.jsonc

@@ -2,12 +2,9 @@
 	"name": "dynamic-worker-loading",
 	"main": "src/index.ts",
 	"compatibility_date": "2023-05-04",
-	"unsafe": {
-		"bindings": [
-			{
-				"name": "LOADER",
-				"type": "worker-loader",
-			},
-		],
-	},
+	"worker_loaders": [
+		{
+			"binding": "LOADER",
+		},
+	],
 }

packages/miniflare/src/plugins/worker-loader/index.ts

@@ -2,9 +2,7 @@ import { z } from "zod";
 import { Worker_Binding } from "../../runtime";
 import { Plugin } from "../shared";
 
-export const WorkerLoaderConfigSchema = z.object({
-	id: z.string().optional(),
-});
+export const WorkerLoaderConfigSchema = z.object({});
 export const WorkerLoaderOptionsSchema = z.object({
 	workerLoaders: z.record(WorkerLoaderConfigSchema).optional(),
 });

packages/wrangler/src/__tests__/config/configuration.test.ts

@@ -7,6 +7,7 @@ import { normalizeString } from "../helpers/normalize";
 import { runInTempDir } from "../helpers/run-in-tmp";
 import { writeWranglerConfig } from "../helpers/write-wrangler-config";
 import type {
+	Config,
 	ConfigFields,
 	RawConfig,
 	RawDevConfig,
@@ -78,6 +79,8 @@ describe("normalizeAndValidateConfig()", () => {
 				upstream_protocol: "http",
 				host: undefined,
 				enable_containers: true,
+				inspector_port: undefined,
+				container_engine: undefined,
 			},
 			containers: undefined,
 			cloudchamber: {},
@@ -92,7 +95,6 @@ describe("normalizeAndValidateConfig()", () => {
 			legacy_env: true,
 			logfwdr: {
 				bindings: [],
-				schema: undefined,
 			},
 			send_metrics: undefined,
 			main: undefined,
@@ -125,7 +127,6 @@ describe("normalizeAndValidateConfig()", () => {
 			},
 			dispatch_namespaces: [],
 			mtls_certificates: [],
-			usage_model: undefined,
 			vars: {},
 			define: {},
 			definedEnvironments: [],
@@ -134,18 +135,30 @@ describe("normalizeAndValidateConfig()", () => {
 			data_blobs: undefined,
 			workers_dev: undefined,
 			preview_urls: undefined,
-			zone_id: undefined,
 			no_bundle: undefined,
 			minify: undefined,
 			first_party_worker: undefined,
 			keep_vars: undefined,
 			logpush: undefined,
 			upload_source_maps: undefined,
 			placement: undefined,
+			worker_loaders: [],
 			tail_consumers: undefined,
 			pipelines: [],
 			workflows: [],
-		});
+			userConfigPath: undefined,
+			topLevelName: undefined,
+			alias: undefined,
+			find_additional_modules: undefined,
+			preserve_file_names: undefined,
+			base_dir: undefined,
+			limits: undefined,
+			keep_names: undefined,
+			assets: undefined,
+			observability: undefined,
+			compliance_region: undefined,
+			images: undefined,
+		} satisfies Config);
 		expect(diagnostics.hasErrors()).toBe(false);
 		expect(diagnostics.hasWarnings()).toBe(false);
 	});
@@ -3978,6 +3991,91 @@ describe("normalizeAndValidateConfig()", () => {
 			});
 		});
 
+		describe("[worker_loaders]", () => {
+			it("should error if worker_loaders is an object", () => {
+				const { diagnostics } = normalizeAndValidateConfig(
+					// @ts-expect-error purposely using an invalid value
+					{ worker_loaders: {} },
+					undefined,
+					undefined,
+					{ env: undefined }
+				);
+
+				expect(diagnostics.hasWarnings()).toBe(false);
+				expect(diagnostics.renderErrors()).toMatchInlineSnapshot(`
+			"Processing wrangler configuration:
+			  - The field \\"worker_loaders\\" should be an array but got {}."
+		`);
+			});
+
+			it("should error if worker_loaders is null", () => {
+				const { diagnostics } = normalizeAndValidateConfig(
+					// @ts-expect-error purposely using an invalid value
+					{ worker_loaders: null },
+					undefined,
+					undefined,
+					{ env: undefined }
+				);
+
+				expect(diagnostics.hasWarnings()).toBe(false);
+				expect(diagnostics.renderErrors()).toMatchInlineSnapshot(`
+			"Processing wrangler configuration:
+			  - The field \\"worker_loaders\\" should be an array but got null."
+		`);
+			});
+
+			it("should accept valid bindings", () => {
+				const { diagnostics } = normalizeAndValidateConfig(
+					{
+						worker_loaders: [
+							{
+								binding: "VALID",
+							},
+						],
+					},
+					undefined,
+					undefined,
+					{ env: undefined }
+				);
+
+				expect(diagnostics.hasErrors()).toBe(false);
+			});
+
+			it("should error if worker_loaders bindings are not valid", () => {
+				const { diagnostics } = normalizeAndValidateConfig(
+					{
+						worker_loaders: [
+							// @ts-expect-error Test if empty object is caught
+							{},
+							{
+								binding: "VALID",
+							},
+							{
+								// @ts-expect-error Test if binding is not a string
+								binding: null,
+								invalid: true,
+							},
+						],
+					},
+					undefined,
+					undefined,
+					{ env: undefined }
+				);
+
+				expect(diagnostics.hasWarnings()).toBe(true);
+				expect(diagnostics.renderWarnings()).toMatchInlineSnapshot(`
+					"Processing wrangler configuration:
+					  - Unexpected fields found in worker_loaders[2] field: \\"invalid\\""
+				`);
+				expect(diagnostics.hasErrors()).toBe(true);
+				expect(diagnostics.renderErrors()).toMatchInlineSnapshot(`
+					"Processing wrangler configuration:
+					  - \\"worker_loaders[0]\\" bindings must have a string \\"binding\\" field but got {}.
+					  - \\"worker_loaders[2]\\" bindings must have a string \\"binding\\" field but got {\\"binding\\":null,\\"invalid\\":true}."
+				`);
+			});
+		});
+
 		describe("[unsafe_hello_world]", () => {
 			it("should error if unsafe_hello_world is an object", () => {
 				const { diagnostics } = normalizeAndValidateConfig(

packages/wrangler/src/__tests__/type-generation.test.ts

@@ -263,6 +263,11 @@ const bindingsConfigMock: Omit<
 			},
 		},
 	],
+	worker_loaders: [
+		{
+			binding: "WORKER_LOADER_BINDING",
+		},
+	],
 };
 
 describe("generate types", () => {
@@ -480,6 +485,7 @@ describe("generate types", () => {
 					SECRET: SecretsStoreSecret;
 					HELLO_WORLD: HelloWorldBinding;
 					RATE_LIMITER: RateLimit;
+					WORKER_LOADER_BINDING: WorkerLoader;
 					SERVICE_BINDING: Fetcher /* service_name */;
 					OTHER_SERVICE_BINDING: Service /* entrypoint FakeEntrypoint from service_name_2 */;
 					OTHER_SERVICE_BINDING_ENTRYPOINT: Service /* entrypoint RealEntrypoint from service_name_2 */;
@@ -579,6 +585,7 @@ describe("generate types", () => {
 					SECRET: SecretsStoreSecret;
 					HELLO_WORLD: HelloWorldBinding;
 					RATE_LIMITER: RateLimit;
+					WORKER_LOADER_BINDING: WorkerLoader;
 					SERVICE_BINDING: Fetcher /* service_name */;
 					OTHER_SERVICE_BINDING: Service /* entrypoint FakeEntrypoint from service_name_2 */;
 					OTHER_SERVICE_BINDING_ENTRYPOINT: Service /* entrypoint RealEntrypoint from service_name_2 */;
@@ -742,6 +749,7 @@ describe("generate types", () => {
 					SECRET: SecretsStoreSecret;
 					HELLO_WORLD: HelloWorldBinding;
 					RATE_LIMITER: RateLimit;
+					WORKER_LOADER_BINDING: WorkerLoader;
 					SERVICE_BINDING: Service<typeof import(\\"../b/index\\").default>;
 					OTHER_SERVICE_BINDING: Service /* entrypoint FakeEntrypoint from service_name_2 */;
 					OTHER_SERVICE_BINDING_ENTRYPOINT: Service<typeof import(\\"../c/index\\").RealEntrypoint>;

packages/wrangler/src/api/startDevWorker/types.ts

@@ -32,6 +32,7 @@ import type {
 	CfTailConsumer,
 	CfUnsafe,
 	CfVectorize,
+	CfWorkerLoader,
 	CfWorkflow,
 } from "../../deployment-bundle/worker";
 import type { CfAccount } from "../../dev/create-worker-preview";
@@ -304,6 +305,7 @@ export type Binding =
 	| ({ type: "logfwdr" } & NameOmit<CfLogfwdrBinding>)
 	| ({ type: "unsafe_hello_world" } & BindingOmit<CfHelloWorld>)
 	| ({ type: "ratelimit" } & NameOmit<CfRateLimit>)
+	| ({ type: "worker_loader" } & BindingOmit<CfWorkerLoader>)
 	| { type: `unsafe_${string}` }
 	| { type: "assets" };
 

packages/wrangler/src/api/startDevWorker/utils.ts

@@ -287,6 +287,12 @@ export function convertCfWorkerInitBindingsToBindings(
 				}
 				break;
 			}
+			case "worker_loaders": {
+				for (const { binding, ...x } of info) {
+					output[binding] = { type: "worker_loader", ...x };
+				}
+				break;
+			}
 			default: {
 				assertNever(type);
 			}
@@ -331,6 +337,7 @@ export async function convertBindingsToCfWorkerInitBindings(
 		pipelines: undefined,
 		unsafe_hello_world: undefined,
 		ratelimits: undefined,
+		worker_loaders: undefined,
 	};
 
 	const fetchers: Record<string, ServiceFetch> = {};
@@ -423,6 +430,9 @@ export async function convertBindingsToCfWorkerInitBindings(
 		} else if (binding.type === "ratelimit") {
 			bindings.ratelimits ??= [];
 			bindings.ratelimits.push({ ...binding, name: name });
+		} else if (binding.type === "worker_loader") {
+			bindings.worker_loaders ??= [];
+			bindings.worker_loaders.push({ ...binding, binding: name });
 		} else if (isUnsafeBindingType(binding.type)) {
 			bindings.unsafe ??= {
 				bindings: [],

packages/wrangler/src/config/config.ts

@@ -335,6 +335,7 @@ export const defaultWranglerConfig: Config = {
 	version_metadata: undefined,
 	unsafe_hello_world: [],
 	ratelimits: [],
+	worker_loaders: [],
 
 	/*====================================================*/
 	/*           Fields supported by Workers only         */

packages/wrangler/src/config/environment.ts

@@ -1173,6 +1173,20 @@ export interface EnvironmentNonInheritable {
 			period: 10 | 60;
 		};
 	}[];
+
+	/**
+	 * Specifies Worker Loader bindings that are bound to this Worker environment.
+	 *
+	 * NOTE: This field is not automatically inherited from the top level environment,
+	 * and so must be specified in every named environment.
+	 *
+	 * @default []
+	 * @nonInheritable
+	 */
+	worker_loaders: {
+		/** The binding name used to refer to the Worker Loader in the Worker. */
+		binding: string;
+	}[];
 }
 
 /**

packages/wrangler/src/config/validation.ts

@@ -1454,6 +1454,16 @@ function normalizeAndValidateEnvironment(
 			validateBindingArray(envName, validateHelloWorldBinding),
 			[]
 		),
+		worker_loaders: notInheritable(
+			diagnostics,
+			topLevelEnv,
+			rawConfig,
+			rawEnv,
+			envName,
+			"worker_loaders",
+			validateBindingArray(envName, validateWorkerLoaderBinding),
+			[]
+		),
 		ratelimits: notInheritable(
 			diagnostics,
 			topLevelEnv,
@@ -2385,6 +2395,7 @@ const validateUnsafeBinding: ValidatorFn = (diagnostics, field, value) => {
 			"logfwdr",
 			"mtls_certificate",
 			"pipeline",
+			"worker-loader",
 		];
 
 		if (safeBindings.includes(value.type)) {
@@ -3867,6 +3878,34 @@ const validateHelloWorldBinding: ValidatorFn = (diagnostics, field, value) => {
 	return isValid;
 };
 
+const validateWorkerLoaderBinding: ValidatorFn = (
+	diagnostics,
+	field,
+	value
+) => {
+	if (typeof value !== "object" || value === null) {
+		diagnostics.errors.push(
+			`"worker_loader" bindings should be objects, but got ${JSON.stringify(value)}`
+		);
+		return false;
+	}
+	let isValid = true;
+	if (!isRequiredProperty(value, "binding", "string")) {
+		diagnostics.errors.push(
+			`"${field}" bindings must have a string "binding" field but got ${JSON.stringify(
+				value
+			)}.`
+		);
+		isValid = false;
+	}
+
+	validateAdditionalProperties(diagnostics, field, Object.keys(value), [
+		"binding",
+	]);
+
+	return isValid;
+};
+
 const validateRateLimitBinding: ValidatorFn = (diagnostics, field, value) => {
 	if (typeof value !== "object" || value === null) {
 		diagnostics.errors.push(

packages/wrangler/src/deployment-bundle/bindings.ts

@@ -76,6 +76,7 @@ export function getBindings(
 				},
 		unsafe_hello_world: options?.pages ? undefined : config?.unsafe_hello_world,
 		ratelimits: config?.ratelimits,
+		worker_loaders: config?.worker_loaders,
 	};
 }
 

packages/wrangler/src/deployment-bundle/create-worker-upload-form.ts

@@ -158,6 +158,10 @@ export type WorkerMetadataBinding =
 			namespace_id: string;
 			simple: { limit: number; period: 10 | 60 };
 	  }
+	| {
+			type: "worker-loader";
+			name: string;
+	  }
 	| {
 			type: "logfwdr";
 			name: string;
@@ -499,6 +503,13 @@ export function createWorkerUploadForm(worker: CfWorkerInit): FormData {
 		});
 	});
 
+	bindings.worker_loaders?.forEach(({ binding }) => {
+		metadataBindings.push({
+			name: binding,
+			type: "worker-loader",
+		});
+	});
+
 	bindings.logfwdr?.bindings.forEach(({ name, destination }) => {
 		metadataBindings.push({
 			name: name,