Enable moduleRoot option for modules: true

This changes which directory Miniflare's automatic module location
resolves module names from paths relative to. Note Miniflare's
source-mapping support already accounts for `modulesRoot`.

Whilst this could've been used to support `__STATIC_CONTENT_MANIFEST`
imports in non-root directories, you would still only be able to
import the manifest in a single directory, just not the root one.

Author: mrbbot

packages/miniflare/README.md

@@ -234,8 +234,9 @@ parameter in module format Workers.
 
 - `modulesRoot?: string`
 
-  If `modules` is set to an array, modules' "name"s will be their `path`s
-  relative to this value. This ensures file paths in stack traces are correct.
+  If `modules` is set to `true` or an array, modules' "name"s will be their
+  `path`s relative to this value. This ensures file paths in stack traces are
+  correct.
 
 <!-- prettier-ignore-start -->
 <!-- (for disabling `;` insertion in `js` code block) -->

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

@@ -563,10 +563,10 @@ function getWorkerScript(
   options: SourceOptions,
   workerIndex: number
 ): { serviceWorkerScript: string } | { modules: Worker_Module[] } {
+  const modulesRoot =
+    ("modulesRoot" in options ? options.modulesRoot : undefined) ?? "";
   if (Array.isArray(options.modules)) {
     // If `modules` is a manually defined modules array, use that
-    const modulesRoot =
-      ("modulesRoot" in options ? options.modulesRoot : undefined) ?? "";
     return {
       modules: options.modules.map((module) =>
         convertModuleDefinition(sourceMapRegistry, modulesRoot, module)
@@ -589,7 +589,11 @@ function getWorkerScript(
 
   if (options.modules) {
     // If `modules` is `true`, automatically collect modules...
-    const locator = new ModuleLocator(sourceMapRegistry, options.modulesRules);
+    const locator = new ModuleLocator(
+      sourceMapRegistry,
+      modulesRoot,
+      options.modulesRules
+    );
     // If `script` and `scriptPath` are set, resolve modules in `script`
     // against `scriptPath`.
     locator.visitEntrypoint(

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

@@ -80,6 +80,9 @@ export const SourceOptionsSchema = z.union([
     modules: z.boolean().optional(),
     // How to interpret automatically collected modules
     modulesRules: z.array(ModuleRuleSchema).optional(),
+    // `modules` "name"s will be their paths relative to this value.
+    // This ensures file paths in stack traces are correct.
+    modulesRoot: z.string().optional(),
   }),
   z.object({
     scriptPath: z.string(),
@@ -88,6 +91,9 @@ export const SourceOptionsSchema = z.union([
     modules: z.boolean().optional(),
     // How to interpret automatically collected modules
     modulesRules: z.array(ModuleRuleSchema).optional(),
+    // `modules` "name"s will be their paths relative to this value.
+    // This ensures file paths in stack traces are correct.
+    modulesRoot: z.string().optional(),
   }),
 ]);
 export type SourceOptions = z.infer<typeof SourceOptionsSchema>;
@@ -123,13 +129,15 @@ function getResolveErrorPrefix(referencingPath: string): string {
 }
 
 export class ModuleLocator {
-  readonly #sourceMapRegistry: SourceMapRegistry;
   readonly #compiledRules: CompiledModuleRule[];
   readonly #visitedPaths = new Set<string>();
   readonly modules: Worker_Module[] = [];
 
-  constructor(sourceMapRegistry: SourceMapRegistry, rules?: ModuleRule[]) {
-    this.#sourceMapRegistry = sourceMapRegistry;
+  constructor(
+    private readonly sourceMapRegistry: SourceMapRegistry,
+    private readonly modulesRoot: string,
+    rules?: ModuleRule[]
+  ) {
     this.#compiledRules = compileModuleRules(rules);
   }
 
@@ -146,8 +154,8 @@ export class ModuleLocator {
 
   #visitJavaScriptModule(code: string, modulePath: string, esModule = true) {
     // Register module
-    const name = path.relative("", modulePath);
-    code = this.#sourceMapRegistry.register(code, modulePath);
+    const name = path.relative(this.modulesRoot, modulePath);
+    code = this.sourceMapRegistry.register(code, modulePath);
     this.modules.push(
       esModule ? { name, esModule: code } : { name, commonJsModule: code }
     );
@@ -255,7 +263,7 @@ ${dim(modulesConfig)}`;
 
     const identifier = path.resolve(path.dirname(referencingPath), spec);
     // The runtime requires module identifiers to be relative paths
-    const name = path.relative("", identifier);
+    const name = path.relative(this.modulesRoot, identifier);
 
     // If we've already visited this path, return to avoid unbounded recursion
     if (this.#visitedPaths.has(identifier)) return;

packages/miniflare/test/plugins/core/errors/index.spec.ts

@@ -114,6 +114,14 @@ test("source maps workers", async (t) => {
       {
         name: "g",
         routes: ["*/g"],
+        bindings: { MESSAGE: "g" },
+        modules: true,
+        modulesRoot: tmp,
+        scriptPath: modulesPath,
+      },
+      {
+        name: "h",
+        routes: ["*/h"],
         modules: [
           // Check importing module with source map (e.g. Wrangler no bundle with built dependencies)
           {
@@ -125,7 +133,7 @@ test("source maps workers", async (t) => {
         ],
       },
       {
-        name: "h",
+        name: "i",
         // Generated with `esbuild --sourcemap=inline --sources-content=false worker.ts`
         script: `"use strict";
 addEventListener("fetch", (event) => {
@@ -174,6 +182,10 @@ addEventListener("fetch", (event) => {
   });
   t.regex(String(error?.stack), modulesEntryRegexp);
   error = await t.throwsAsync(mf.dispatchFetch("http://localhost/g"), {
+    message: "g",
+  });
+  t.regex(String(error?.stack), modulesEntryRegexp);
+  error = await t.throwsAsync(mf.dispatchFetch("http://localhost/h"), {
     instanceOf: TypeError,
     message: "Dependency error",
   });
@@ -196,6 +208,8 @@ addEventListener("fetch", (event) => {
   sources = await getSources(inspectorPort, "core:user:f");
   t.deepEqual(sources, [MODULES_ENTRY_PATH, REDUCE_PATH]);
   sources = await getSources(inspectorPort, "core:user:g");
+  t.deepEqual(sources, [MODULES_ENTRY_PATH, REDUCE_PATH]);
+  sources = await getSources(inspectorPort, "core:user:h");
   t.deepEqual(sources, [DEP_ENTRY_PATH, REDUCE_PATH]); // (entry point script overridden)
 
   // Check respects map's existing `sourceRoot`
@@ -216,11 +230,11 @@ addEventListener("fetch", (event) => {
   ]);
 
   // Check does nothing with URL source mapping URLs
-  const sourceMapURL = await getSourceMapURL(inspectorPort, "core:user:h");
+  const sourceMapURL = await getSourceMapURL(inspectorPort, "core:user:i");
   t.regex(sourceMapURL, /^data:application\/json;base64/);
 
   // Check adds ignored sources to `x_google_ignoreList`
-  const sourceMap = await getSourceMap(inspectorPort, "core:user:g");
+  const sourceMap = await getSourceMap(inspectorPort, "core:user:h");
   assert(sourceMap.sourceRoot !== undefined);
   assert(sourceMap.x_google_ignoreList?.length === 1);
   const ignoredSource = sourceMap.sources[sourceMap.x_google_ignoreList[0]];