[miniflare] Fix source phase imports parsing in module analysis

.changeset/four-planes-attend.md

@@ -0,0 +1,7 @@
+---
+"wrangler": patch
+---
+
+Fix source phase imports in bundled and non-bundled Workers
+
+Wrangler now preserves `import source` syntax when it runs esbuild, including module format detection and bundled deploy output. This fixes both `--no-bundle` and bundled deployments for Workers that import WebAssembly using source phase imports.

.changeset/source-phase-miniflare.md

@@ -0,0 +1,7 @@
+---
+"miniflare": patch
+---
+
+Fix source phase imports parsing in Miniflare
+
+Miniflare now uses the `acorn-import-phases` plugin to parse `import source` syntax when analyzing module dependencies. This fixes `ERR_MODULE_PARSE` errors when running Workers that use source phase imports for WebAssembly modules in local development.

packages/miniflare/package.json

@@ -77,6 +77,7 @@
 		"@types/which": "^2.0.1",
 		"@types/ws": "^8.5.7",
 		"acorn": "8.14.0",
+		"acorn-import-phases": "^1.0.4",
 		"acorn-walk": "8.3.2",
 		"capnp-es": "catalog:default",
 		"capnweb": "catalog:default",

packages/miniflare/src/plugins/core/modules.ts

@@ -4,7 +4,8 @@ import { builtinModules } from "node:module";
 import path from "node:path";
 import { pathToFileURL } from "node:url";
 import { TextDecoder, TextEncoder } from "node:util";
-import { parse } from "acorn";
+import { Parser } from "acorn";
+import importPhases from "acorn-import-phases";
 import { simple } from "acorn-walk";
 import { dim } from "kleur/colors";
 import { z } from "zod";
@@ -14,6 +15,9 @@ import { MatcherRegExps, testRegExps } from "../../workers";
 import { getNodeCompat, NodeJSCompatMode } from "./node-compat";
 import type estree from "estree";
 
+const ExtendedParser = Parser.extend(importPhases());
+const parse = ExtendedParser.parse.bind(ExtendedParser);
+
 const SUGGEST_BUNDLE =
 	"If you're trying to import an npm package, you'll need to bundle your Worker first.";
 const SUGGEST_NODE =

packages/miniflare/test/plugins/core/modules.spec.ts

@@ -339,3 +339,44 @@ If you're trying to import an npm package, you'll need to bundle your Worker fir
 		/^Unable to resolve "index\.mjs" dependency "node:assert": no matching module rules\.\nIf you're trying to import a Node\.js built-in module, or an npm package that uses Node\.js built-ins, you'll either need to:/
 	);
 });
+test("Miniflare: parses source phase imports without error", async ({
+	expect,
+}) => {
+	const tmp = await useTmp();
+	const wasmPath = path.join(tmp, "module.wasm");
+	const workerPath = path.join(tmp, "index.mjs");
+
+	// Create a minimal wasm file
+	await fs.writeFile(
+		wasmPath,
+		Buffer.from([0x00, 0x61, 0x73, 0x6d, 0x01, 0x00, 0x00, 0x00])
+	);
+
+	// Create a worker that uses source phase import syntax
+	await fs.writeFile(
+		workerPath,
+		`import source wasmModule from "./module.wasm";
+export default {
+  async fetch() {
+    return new Response("source phase import parsed successfully");
+  }
+};`
+	);
+
+	// Verify the worker can be loaded without parse errors
+	// Note: workerd doesn't actually support source phase imports at runtime,
+	// but we need to ensure the parser doesn't fail on the syntax
+	const mf = new Miniflare({
+		modules: true,
+		modulesRoot: tmp,
+		modulesRules: [{ type: "CompiledWasm", include: ["**/*.wasm"] }],
+		compatibilityDate: "2023-08-01",
+		scriptPath: workerPath,
+	});
+	useDispose(mf);
+
+	// The worker should be able to load (even if the source phase import
+	// is not fully functional at runtime)
+	const res = await mf.dispatchFetch("http://localhost");
+	expect(await res.text()).toBe("source phase import parsed successfully");
+});