fix: config preview_urls defaults to undefined (falsy) instead of true

We want preview_urls to be opt-in, rather than opt-out. For this reason
its default value will be falsy.

Author: danielrs

.changeset/ready-banks-repair.md

@@ -0,0 +1,8 @@
+---
+"wrangler": minor
+---
+
+Beta feature preview_urls is now disabled by default.
+
+This change makes preview_urls disabled by default when it's not provided, making
+the feature opt-in instead of opt-out.

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

@@ -130,7 +130,7 @@ describe("normalizeAndValidateConfig()", () => {
 			wasm_modules: undefined,
 			data_blobs: undefined,
 			workers_dev: undefined,
-			preview_urls: true,
+			preview_urls: undefined,
 			zone_id: undefined,
 			no_bundle: undefined,
 			minify: undefined,

packages/wrangler/src/__tests__/deploy.test.ts

@@ -1898,7 +1898,7 @@ Update them to point to this script instead?`,
 				});
 				await mockAUSRequest([]);
 				mockSubDomainRequest();
-				mockUpdateWorkerSubdomain({ enabled: false, previews_enabled: true });
+				mockUpdateWorkerSubdomain({ enabled: false, previews_enabled: false });
 				mockUploadWorkerRequest({
 					expectedAssets: {
 						jwt: "<<aus-completion-token>>",
@@ -1983,7 +1983,7 @@ Update them to point to this script instead?`,
 				});
 				await mockAUSRequest([]);
 				mockSubDomainRequest();
-				mockUpdateWorkerSubdomain({ enabled: false, previews_enabled: true });
+				mockUpdateWorkerSubdomain({ enabled: false, previews_enabled: false });
 				mockUploadWorkerRequest({
 					expectedAssets: {
 						jwt: "<<aus-completion-token>>",
@@ -2046,7 +2046,7 @@ Update them to point to this script instead?`,
 				writeWorkerSource();
 				await mockAUSRequest([]);
 				mockSubDomainRequest();
-				mockUpdateWorkerSubdomain({ enabled: false, previews_enabled: true });
+				mockUpdateWorkerSubdomain({ enabled: false, previews_enabled: false });
 				mockUploadWorkerRequest({
 					expectedAssets: {
 						jwt: "<<aus-completion-token>>",
@@ -2116,7 +2116,7 @@ Update them to point to this script instead?`,
 				});
 				await mockAUSRequest([]);
 				mockSubDomainRequest();
-				mockUpdateWorkerSubdomain({ enabled: false, previews_enabled: true });
+				mockUpdateWorkerSubdomain({ enabled: false, previews_enabled: false });
 				mockUploadWorkerRequest({
 					expectedAssets: {
 						jwt: "<<aus-completion-token>>",

packages/wrangler/src/__tests__/helpers/mock-upload-worker.ts

@@ -1,7 +1,12 @@
 import { http, HttpResponse } from "msw";
+import { Route } from "../../config/environment";
+import { ParseError } from "../../parse";
+import { getSubdomainDefaults } from "../../triggers/deploy";
 import { mockGetWorkerSubdomain } from "./mock-workers-subdomain";
 import { createFetchResult, msw } from "./msw";
 import { serialize, toString } from "./serialize-form-data-entry";
+import { readWranglerConfig } from "./write-wrangler-config";
+import type { RawConfig } from "../../config";
 import type {
 	AssetConfigMetadata,
 	WorkerMetadata,
@@ -236,9 +241,27 @@ export function mockUploadWorkerRequest(
 			)
 		);
 	}
-	// TODO make explicit by callers?
+	// Every upload is followed by a GET subdomain request, to check if the worker is enabled.
+	// TODO: make this explicit by callers?
+	let config: RawConfig = {};
+	try {
+		config = readWranglerConfig();
+	} catch (e) {
+		if (e instanceof ParseError) {
+			// Ignore, config is either bad or doesn't exist.
+		} else {
+			throw e;
+		}
+	}
+	let routes: Route[] = config.routes ?? [];
+	if (env) {
+		routes = config.env?.[env]?.routes ?? [];
+	}
+	const { workers_dev: defaultWorkersDev, preview_urls: defaultPreviewUrls } =
+		getSubdomainDefaults(routes);
 	mockGetWorkerSubdomain({
-		enabled: true,
+		enabled: config.workers_dev ?? defaultWorkersDev,
+		previews_enabled: config.preview_urls ?? defaultPreviewUrls,
 		env,
 		legacyEnv,
 		expectedScriptName,

packages/wrangler/src/__tests__/helpers/mock-workers-subdomain.ts

@@ -36,7 +36,7 @@ export function mockSubDomainRequest(
 /** Create a mock handler to fetch the  <script>.<user>.workers.dev subdomain status*/
 export function mockGetWorkerSubdomain({
 	enabled,
-	previews_enabled = true,
+	previews_enabled = false,
 	env,
 	legacyEnv = false,
 	expectedScriptName = "test-name" + (legacyEnv && env ? `-${env}` : ""),
@@ -73,7 +73,7 @@ export function mockGetWorkerSubdomain({
 /** Create a mock handler to toggle a <script>.<user>.workers.dev subdomain status */
 export function mockUpdateWorkerSubdomain({
 	enabled,
-	previews_enabled = true,
+	previews_enabled = false,
 	env,
 	legacyEnv = false,
 	expectedScriptName = "test-name",

packages/wrangler/src/__tests__/helpers/write-wrangler-config.ts

@@ -1,6 +1,6 @@
 import * as fs from "node:fs";
 import { dirname } from "node:path";
-import { formatConfigSnippet } from "../../config";
+import { formatConfigSnippet, parseRawConfigFile } from "../../config";
 import type { RawConfig } from "../../config";
 
 /** Write a mock wrangler config file to disk. */
@@ -24,3 +24,7 @@ export function writeWranglerConfig(
 		"utf-8"
 	);
 }
+
+export function readWranglerConfig(path = "./wrangler.toml"): RawConfig {
+	return parseRawConfigFile(path);
+}

packages/wrangler/src/config/config.ts

@@ -346,7 +346,7 @@ export const defaultWranglerConfig: Config = {
 	preserve_file_names: undefined,
 	base_dir: undefined,
 	workers_dev: undefined,
-	preview_urls: true,
+	preview_urls: undefined,
 	route: undefined,
 	routes: undefined,
 	tsconfig: undefined,

packages/wrangler/src/config/environment.ts

@@ -312,7 +312,7 @@ interface EnvironmentInheritable {
 	 * Whether we use <version>-<name>.<subdomain>.workers.dev to
 	 * serve Preview URLs for your Worker.
 	 *
-	 * @default true
+	 * @default false
 	 * @inheritable
 	 */
 	preview_urls: boolean | undefined;

packages/wrangler/src/config/validation.ts

@@ -1059,7 +1059,7 @@ function normalizeAndValidateEnvironment(
 		rawEnv,
 		"preview_urls",
 		isBoolean,
-		true
+		undefined
 	);
 
 	const build = normalizeAndValidateBuild(

packages/wrangler/src/triggers/deploy.ts

@@ -292,6 +292,13 @@ export default async function triggersDeploy(
 	}
 }
 
+export function getSubdomainDefaults(routes: Route[]) {
+	return {
+		workers_dev: routes.length === 0,
+		preview_urls: false,
+	};
+}
+
 async function subdomainDeploy(
 	props: Props,
 	accountId: string,
@@ -305,9 +312,10 @@ async function subdomainDeploy(
 
 	// Get desired subdomain enablement status.
 
-	const defaultWorkersDev = routes.length === 0;
+	const { workers_dev: defaultWorkersDev, preview_urls: defaultPreviews } =
+		getSubdomainDefaults(routes);
 	const wantWorkersDev = config.workers_dev ?? defaultWorkersDev;
-	const wantPreviews = config.preview_urls ?? false;
+	const wantPreviews = config.preview_urls ?? defaultPreviews;
 
 	// Get current subdomain enablement status.