fix(compartment-mapper): remove the file: protocol from __filename an…

packages/compartment-mapper/NEWS.md

@@ -15,7 +15,12 @@ User-visible changes to the compartment mapper:
   We still allow for the possibility that these duplicates exist and in fact
   may contain different sources, since they may be retained as dependencies
   beyond the purview of npm.
-- A package.json file with the "type" field nested within a package's folder structure a is now taken into account when determining if a .js file is an ES module.
+- A package.json file with the "type" field nested within a package's folder 
+  structure a is now taken into account when determining if a .js file is an 
+  ES module.
+- Adds means to make `__dirname` and `__filename` work in CommonJS modules when
+  loaded via importLocation or loadLocation. Pass `readPowers` with 
+  `fileURLToPath` method present.
 
 # 0.7.2 (2022-04-11)
 

packages/compartment-mapper/src/import-hook.js

@@ -3,13 +3,15 @@
 /** @typedef {import('ses').ImportHook} ImportHook */
 /** @typedef {import('ses').StaticModuleType} StaticModuleType */
 /** @typedef {import('./types.js').ReadFn} ReadFn */
+/** @typedef {import('./types.js').ReadPowers} ReadPowers */
 /** @typedef {import('./types.js').HashFn} HashFn */
 /** @typedef {import('./types.js').Sources} Sources */
 /** @typedef {import('./types.js').CompartmentSources} CompartmentSources */
 /** @typedef {import('./types.js').CompartmentDescriptor} CompartmentDescriptor */
 /** @typedef {import('./types.js').ImportHookMaker} ImportHookMaker */
 
 import { parseExtension } from './extension.js';
+import { unpackReadPowers } from './powers.js';
 
 // q, as in quote, for quoting strings in error messages.
 const q = JSON.stringify;
@@ -44,7 +46,7 @@ function getImportsFromRecord(record) {
 }
 
 /**
- * @param {ReadFn} read
+ * @param {ReadFn|ReadPowers} readPowers
  * @param {string} baseLocation
  * @param {Sources} sources
  * @param {Record<string, CompartmentDescriptor>} compartments
@@ -53,7 +55,7 @@ function getImportsFromRecord(record) {
  * @returns {ImportHookMaker}
  */
 export const makeImportHookMaker = (
-  read,
+  readPowers,
   baseLocation,
   sources = Object.create(null),
   compartments = Object.create(null),
@@ -152,6 +154,8 @@ export const makeImportHookMaker = (
         }
       }
 
+      const { read } = unpackReadPowers(readPowers);
+
       for (const candidateSpecifier of candidates) {
         // Using a specifier as a location.
         // This is not always valid.
@@ -172,6 +176,7 @@ export const makeImportHookMaker = (
             candidateSpecifier,
             moduleLocation,
             packageLocation,
+            readPowers,
           );
           const {
             parser,

packages/compartment-mapper/src/import.js

@@ -73,7 +73,7 @@ export const loadLocation = async (readPowers, moduleLocation, options) => {
       __shimTransforms__,
       Compartment,
     } = options;
-    const makeImportHook = makeImportHookMaker(read, packageLocation);
+    const makeImportHook = makeImportHookMaker(readPowers, packageLocation);
     const { compartment } = link(compartmentMap, {
       makeImportHook,
       parserForLanguage,
@@ -92,13 +92,17 @@ export const loadLocation = async (readPowers, moduleLocation, options) => {
 };
 
 /**
- * @param {ReadFn} read
+ * @param {ReadFn | ReadPowers} readPowers
  * @param {string} moduleLocation
  * @param {ExecuteOptions & ArchiveOptions} [options]
  * @returns {Promise<Object>} the object of the imported modules exported
  * names.
  */
-export const importLocation = async (read, moduleLocation, options = {}) => {
-  const application = await loadLocation(read, moduleLocation, options);
+export const importLocation = async (
+  readPowers,
+  moduleLocation,
+  options = {},
+) => {
+  const application = await loadLocation(readPowers, moduleLocation, options);
   return application.import(options);
 };

packages/compartment-mapper/src/link.js

@@ -77,7 +77,7 @@ const makeExtensionParser = (
   parserForLanguage,
   transforms,
 ) => {
-  return async (bytes, specifier, location, packageLocation) => {
+  return async (bytes, specifier, location, packageLocation, readPowers) => {
     let language;
     if (has(languageForModuleSpecifier, specifier)) {
       language = languageForModuleSpecifier[specifier];
@@ -106,7 +106,7 @@ const makeExtensionParser = (
       );
     }
     const { parse } = parserForLanguage[language];
-    return parse(bytes, specifier, location, packageLocation);
+    return parse(bytes, specifier, location, packageLocation, readPowers);
   };
 };
 

packages/compartment-mapper/src/node-powers.js

@@ -90,7 +90,7 @@ const makeReadPowersSloppy = ({ fs, url = undefined, crypto = undefined }) => {
       }
     : undefined;
 
-  return { read, canonical, computeSha512 };
+  return { read, fileURLToPath, pathToFileURL, canonical, computeSha512 };
 };
 
 /**

packages/compartment-mapper/src/parse-cjs-shared-export-wrapper.js

@@ -1,4 +1,8 @@
 // @ts-check
+
+/** @typedef {import('./types.js').ReadFn} ReadFn */
+/** @typedef {import('./types.js').ReadPowers} ReadPowers */
+
 const { apply } = Reflect;
 const { freeze, keys, create, hasOwnProperty, defineProperty } = Object;
 
@@ -9,6 +13,52 @@ const { freeze, keys, create, hasOwnProperty, defineProperty } = Object;
  */
 const has = (object, key) => apply(hasOwnProperty, object, [key]);
 
+const noTrailingSlash = path => {
+  const l = path.length - 1;
+  return path[l] === '\\' || path[l] === '/' ? path.slice(0, -1) : path;
+};
+
+/**
+ * Generates values for __filename and __dirname from location
+ * @param {ReadPowers | ReadFn | undefined} readPowers
+ * @param {string} location
+ * @returns {{
+ *   filename:string|null,
+ *   dirname: string|null
+ * }}
+ */
+export const getModulePaths = (readPowers, location) => {
+  if (
+    readPowers &&
+    typeof readPowers !== 'function' &&
+    readPowers.fileURLToPath
+  ) {
+    let filename = location;
+    let dirname;
+    try {
+      dirname = new URL('./', filename).href;
+    } catch (_) {
+      return {
+        filename: null,
+        dirname: null,
+      };
+    }
+
+    filename = readPowers.fileURLToPath(filename).toString();
+    dirname = noTrailingSlash(readPowers.fileURLToPath(dirname).toString());
+
+    return {
+      filename,
+      dirname,
+    };
+  } else {
+    return {
+      filename: null,
+      dirname: null,
+    };
+  }
+};
+
 /**
  * ModuleEnvironmentRecord wrapper
  * Creates shared export processing primitives to be used both Location and Archive usecases of cjs

packages/compartment-mapper/src/parse-cjs.js

@@ -1,7 +1,7 @@
 // @ts-check
 
 import { analyzeCommonJS } from '@endo/cjs-module-analyzer';
-import { wrap } from './parse-cjs-shared-export-wrapper.js';
+import { wrap, getModulePaths } from './parse-cjs-shared-export-wrapper.js';
 
 const textDecoder = new TextDecoder();
 
@@ -13,6 +13,7 @@ export const parseCjs = async (
   _specifier,
   location,
   _packageLocation,
+  readPowers,
 ) => {
   const source = textDecoder.decode(bytes);
 
@@ -25,6 +26,8 @@ export const parseCjs = async (
     exports.push('default');
   }
 
+  const { filename, dirname } = await getModulePaths(readPowers, location);
+
   /**
    * @param {Object} moduleEnvironmentRecord
    * @param {Compartment} compartment
@@ -41,13 +44,7 @@ export const parseCjs = async (
       resolvedImports,
     );
 
-    functor(
-      require,
-      moduleExports,
-      module,
-      location, // __filename
-      new URL('./', location).toString(), // __dirname
-    );
+    functor(require, moduleExports, module, filename, dirname);
 
     afterExecute();
   };

packages/compartment-mapper/src/parse-pre-cjs.js

@@ -1,31 +1,26 @@
 // @ts-check
 
 import { parseLocatedJson } from './json.js';
-import { wrap } from './parse-cjs-shared-export-wrapper.js';
+import { wrap, getModulePaths } from './parse-cjs-shared-export-wrapper.js';
 
 const textDecoder = new TextDecoder();
 
-const locationParent = location => {
-  const index = location.lastIndexOf('/');
-  if (index >= 0) {
-    return location.slice(0, index);
-  }
-  return location;
-};
-
 /** @type {import('./types.js').ParseFn} */
 export const parsePreCjs = async (
   bytes,
   _specifier,
   location,
   _packageLocation,
+  readPowers,
 ) => {
   const text = textDecoder.decode(bytes);
   const { source, imports, exports, reexports } = parseLocatedJson(
     text,
     location,
   );
 
+  const { filename, dirname } = await getModulePaths(readPowers, location);
+
   /**
    * @param {Object} moduleEnvironmentRecord
    * @param {Compartment} compartment
@@ -40,13 +35,7 @@ export const parsePreCjs = async (
       resolvedImports,
     );
 
-    functor(
-      require,
-      moduleExports,
-      module,
-      location, // __filename
-      locationParent(location), // __dirname
-    );
+    functor(require, moduleExports, module, filename, dirname);
 
     afterExecute();
   };

packages/compartment-mapper/src/types.js

@@ -149,6 +149,8 @@ export {};
  * @property {ReadFn} read
  * @property {CanonicalFn} canonical
  * @property {HashFn} [computeSha512]
+ * @property {Function} [fileURLToPath]
+ * @property {Function} [pathToFileURL]
  */
 
 /**
@@ -195,6 +197,7 @@ export {};
  * @param {string} specifier
  * @param {string} location
  * @param {string} packageLocation
+ * @param {ReadFn | ReadPowers} [readPowers]
  * @returns {Promise<{
  *   bytes: Uint8Array,
  *   parser: Language,