fix: extract ESZIP correctly

Author: eduardoboucas

packages/edge-bundler/deno/vendor/deno.land/x/[email protected]/eszip.ts

@@ -1,7 +1,18 @@
 // CLI utility to build/list/extract/run ESZIPs
 
 import { build, Parser } from "./mod.ts";
-import { dirname, join } from "https://deno.land/[email protected]/path/mod.ts";
+import { dirname, extname, join } from "https://deno.land/[email protected]/path/mod.ts";
+
+const extensions = new Set([
+  ".ts",
+  ".tsx",
+  ".js",
+  ".jsx",
+  ".mjs",
+  ".mts",
+  ".json",
+  ".wasm"
+]);
 
 function hasV2Header(bytes: Uint8Array) {
   const magicV2 = new TextDecoder().decode(bytes.slice(0, 8));
@@ -109,9 +120,13 @@ export async function loadESZIP(filename: string): Promise<ESZIP> {
 
 function url2path(urlString: string) {
   const url = new URL(urlString);
-  const tail = url.pathname.split("/").filter(Boolean);
-  const relativePath = tail.length === 0 ? [".root"] : tail;
-  return join(url.hostname, ...relativePath);
+  let path = join(url.hostname, ...url.pathname.split("/").filter(Boolean));
+
+  if (!extensions.has(extname(path))) {
+    path = join(path, ".index.ts");
+  }
+
+  return path;
 }
 
 async function write(path: string, content: string) {

packages/edge-bundler/node/bundler.ts

@@ -22,6 +22,7 @@ import { writeManifest } from './manifest.js'
 import { vendorNPMSpecifiers } from './npm_dependencies.js'
 import { ensureLatestTypes } from './types.js'
 import { nonNullable } from './utils/non_nullable.js'
+import { BundleError } from './bundle_error.js'
 
 export interface BundleOptions {
   basePath?: string
@@ -249,26 +250,35 @@ const getFunctionConfigs = async ({
       throw err
     }
 
-    // We failed to extract the configuration because there is an import assert
-    // in the function code, a deprecated feature that we used to support with
-    // Deno 1.x. To avoid a breaking change, we treat this error as a special
-    // case, using the generated ESZIP to extract the configuration. This works
-    // because import asserts are transpiled to import attributes.
-    const extractedESZIP = await extractESZIP(deno, eszipPath)
-    const configs = await Promise.all(
-      [...internalFunctions, ...userFunctions].map(async (func) => {
-        const relativePath = relative(basePath, func.path)
-        const functionPath = join(extractedESZIP.path, relativePath)
-
-        return [func.name, await getFunctionConfig({ functionPath, importMap, deno, log })] as const
-      }),
-    )
+    try {
+      // We failed to extract the configuration because there is an import assert
+      // in the function code, a deprecated feature that we used to support with
+      // Deno 1.x. To avoid a breaking change, we treat this error as a special
+      // case, using the generated ESZIP to extract the configuration. This works
+      // because import asserts are transpiled to import attributes.
+      const extractedESZIP = await extractESZIP(deno, eszipPath)
+      const configs = await Promise.all(
+        [...internalFunctions, ...userFunctions].map(async (func) => {
+          const relativePath = relative(basePath, func.path)
+          const functionPath = join(extractedESZIP.path, relativePath)
 
-    await extractedESZIP.cleanup()
+          return [func.name, await getFunctionConfig({ functionPath, importMap, deno, log })] as const
+        }),
+      )
 
-    return {
-      internalFunctions: Object.fromEntries(configs.slice(0, internalFunctions.length)),
-      userFunctions: Object.fromEntries(configs.slice(internalFunctions.length)),
+      await extractedESZIP.cleanup()
+
+      return {
+        internalFunctions: Object.fromEntries(configs.slice(0, internalFunctions.length)),
+        userFunctions: Object.fromEntries(configs.slice(internalFunctions.length)),
+      }
+    } catch (err) {
+      throw new BundleError(
+        new Error(
+          'An error occurred while building an edge function that uses an import assertion. Refer to https://ntl.fyi/import-assert for more information.',
+        ),
+        { cause: err },
+      )
     }
   }
 }