Refactor checkFetch from a separate method to a proxy around fetch (#…

…3497) * refactor checkFetch from a separate method to a proxy around fetch * Add changeset * prettier with the right options
cloudflare · Aug 11, 2023 · e8b409e · e8b409e
1 parent 85f2536
commit e8b409e
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Showing 3 changed files with 14 additions and 3 deletions.
diff --git a/.changeset/selfish-files-flow.md b/.changeset/selfish-files-flow.md
@@ -0,0 +1,5 @@
+---
+"wrangler": patch
+---
+
+Refactor dev-only checkedFetch check from a method substitution to a JavaScript Proxy to be able to support Proxied global fetch function.
diff --git a/packages/wrangler/src/bundle.ts b/packages/wrangler/src/bundle.ts
@@ -395,7 +395,6 @@ export async function bundleWorker(
 				// when we do a build of wrangler. (re: https://github.com/cloudflare/workers-sdk/issues/1477)
 				"process.env.NODE_ENV": `"${process.env["NODE_ENV" + ""]}"`,
 				...(legacyNodeCompat ? { global: "globalThis" } : {}),
-				...(checkFetch ? { fetch: "checkedFetch" } : {}),
 				...options.define,
 			},
 		}),

diff --git a/packages/wrangler/templates/checked-fetch.js b/packages/wrangler/templates/checked-fetch.js
@@ -1,6 +1,6 @@
 const urls = new Set();
 
-export function checkedFetch(request, init) {
+function checkURL(request, init) {
 	const url =
 		request instanceof URL
 			? request
@@ -19,5 +19,12 @@ export function checkedFetch(request, init) {
 			);
 		}
 	}
-	return globalThis.fetch(request, init);
 }
+
+globalThis.fetch = new Proxy(globalThis.fetch, {
+	apply(target, thisArg, argArray) {
+		const [request, init] = argArray;
+		checkURL(request, init);
+		return Reflect.apply(target, thisArg, argArray);
+	},
+});