src,lib: retrieve parsed source map url from v8

doc/api/vm.md

@@ -344,6 +344,41 @@ console.log(globalVar);
 // 1000
 ```
 
+### `script.sourceMapURL`
+
+<!-- YAML
+added: REPLACEME
+-->
+
+* {string|undefined}
+
+When the script is compiled from a source that contains a source map magic
+comment, this property will be set to the URL of the source map.
+
+```mjs
+import vm from 'node:vm';
+
+const script = new vm.Script(`
+function myFunc() {}
+//# sourceMappingURL=sourcemap.json
+`);
+
+console.log(script.sourceMapURL);
+// Prints: sourcemap.json
+```
+
+```cjs
+const vm = require('node:vm');
+
+const script = new vm.Script(`
+function myFunc() {}
+//# sourceMappingURL=sourcemap.json
+`);
+
+console.log(script.sourceMapURL);
+// Prints: sourcemap.json
+```
+
 ## Class: `vm.Module`
 
 <!-- YAML

lib/internal/modules/cjs/loader.js

@@ -86,7 +86,8 @@ const {
   filterOwnProperties,
   setOwnProperty,
 } = require('internal/util');
-const vm = require('vm');
+const { Script } = require('vm');
+const { internalCompileFunction } = require('internal/vm');
 const assert = require('internal/assert');
 const fs = require('fs');
 const internalFS = require('internal/fs/utils');
@@ -1073,19 +1074,28 @@ let hasPausedEntry = false;
 function wrapSafe(filename, content, cjsModuleInstance) {
   if (patched) {
     const wrapper = Module.wrap(content);
-    return vm.runInThisContext(wrapper, {
+    const script = new Script(wrapper, {
       filename,
       lineOffset: 0,
-      displayErrors: true,
       importModuleDynamically: async (specifier, _, importAssertions) => {
         const loader = asyncESM.esmLoader;
         return loader.import(specifier, normalizeReferrerURL(filename),
                              importAssertions);
       },
     });
+
+    // Cache the source map for the module if present.
+    if (script.sourceMapURL) {
+      maybeCacheSourceMap(filename, content, this, false, undefined, script.sourceMapURL);
+    }
+
+    return script.runInThisContext({
+      displayErrors: true,
+    });
   }
+
   try {
-    return vm.compileFunction(content, [
+    const result = internalCompileFunction(content, [
       'exports',
       'require',
       'module',
@@ -1099,6 +1109,13 @@ function wrapSafe(filename, content, cjsModuleInstance) {
                              importAssertions);
       },
     });
+
+    // Cache the source map for the module if present.
+    if (result.sourceMapURL) {
+      maybeCacheSourceMap(filename, content, this, false, undefined, result.sourceMapURL);
+    }
+
+    return result.function;
   } catch (err) {
     if (process.mainModule === cjsModuleInstance)
       enrichCJSError(err, content);
@@ -1119,7 +1136,6 @@ Module.prototype._compile = function(content, filename) {
     policy.manifest.assertIntegrity(moduleURL, content);
   }
 
-  maybeCacheSourceMap(filename, content, this);
   const compiledWrapper = wrapSafe(filename, content, this);
 
   let inspectorWrapper = null;

lib/internal/process/pre_execution.js

@@ -579,9 +579,11 @@ function initializeESMLoader() {
 }
 
 function initializeSourceMapsHandlers() {
-  const { setSourceMapsEnabled } =
+  const { setSourceMapsEnabled, getSourceMapsEnabled } =
     require('internal/source_map/source_map_cache');
   process.setSourceMapsEnabled = setSourceMapsEnabled;
+  // Initialize the environment flag of source maps.
+  getSourceMapsEnabled();
 }
 
 function initializeFrozenIntrinsics() {

lib/internal/source_map/source_map_cache.js

@@ -97,7 +97,21 @@ function extractSourceURLMagicComment(content) {
   return sourceURL;
 }
 
-function maybeCacheSourceMap(filename, content, cjsModuleInstance, isGeneratedSource, sourceURL) {
+function extractSourceMapURLMagicComment(content) {
+  let match;
+  let lastMatch;
+  // A while loop is used here to get the last occurrence of sourceMappingURL.
+  // This is needed so that we don't match sourceMappingURL in string literals.
+  while ((match = RegExpPrototypeExec(kSourceMappingURLMagicComment, content))) {
+    lastMatch = match;
+  }
+  if (lastMatch == null) {
+    return null;
+  }
+  return lastMatch.groups.sourceMappingURL;
+}
+
+function maybeCacheSourceMap(filename, content, cjsModuleInstance, isGeneratedSource, sourceURL, sourceMapURL) {
   const sourceMapsEnabled = getSourceMapsEnabled();
   if (!(process.env.NODE_V8_COVERAGE || sourceMapsEnabled)) return;
   try {
@@ -108,52 +122,52 @@ function maybeCacheSourceMap(filename, content, cjsModuleInstance, isGeneratedSo
     return;
   }
 
-  let match;
-  let lastMatch;
-  // A while loop is used here to get the last occurrence of sourceMappingURL.
-  // This is needed so that we don't match sourceMappingURL in string literals.
-  while ((match = RegExpPrototypeExec(kSourceMappingURLMagicComment, content))) {
-    lastMatch = match;
+  if (sourceMapURL === undefined) {
+    sourceMapURL = extractSourceMapURLMagicComment(content);
+  }
+
+  // Bail out when there is no source map url.
+  if (typeof sourceMapURL !== 'string') {
+    return;
   }
 
   if (sourceURL === undefined) {
     sourceURL = extractSourceURLMagicComment(content);
   }
-  if (lastMatch) {
-    const data = dataFromUrl(filename, lastMatch.groups.sourceMappingURL);
-    const url = data ? null : lastMatch.groups.sourceMappingURL;
-    if (cjsModuleInstance) {
-      cjsSourceMapCache.set(cjsModuleInstance, {
-        filename,
-        lineLengths: lineLengths(content),
-        data,
-        url,
-        sourceURL,
-      });
-    } else if (isGeneratedSource) {
-      const entry = {
-        lineLengths: lineLengths(content),
-        data,
-        url,
-        sourceURL
-      };
-      generatedSourceMapCache.set(filename, entry);
-      if (sourceURL) {
-        generatedSourceMapCache.set(sourceURL, entry);
-      }
-    } else {
-      // If there is no cjsModuleInstance and is not generated source assume we are in a
-      // "modules/esm" context.
-      const entry = {
-        lineLengths: lineLengths(content),
-        data,
-        url,
-        sourceURL,
-      };
-      esmSourceMapCache.set(filename, entry);
-      if (sourceURL) {
-        esmSourceMapCache.set(sourceURL, entry);
-      }
+
+  const data = dataFromUrl(filename, sourceMapURL);
+  const url = data ? null : sourceMapURL;
+  if (cjsModuleInstance) {
+    cjsSourceMapCache.set(cjsModuleInstance, {
+      filename,
+      lineLengths: lineLengths(content),
+      data,
+      url,
+      sourceURL,
+    });
+  } else if (isGeneratedSource) {
+    const entry = {
+      lineLengths: lineLengths(content),
+      data,
+      url,
+      sourceURL
+    };
+    generatedSourceMapCache.set(filename, entry);
+    if (sourceURL) {
+      generatedSourceMapCache.set(sourceURL, entry);
+    }
+  } else {
+    // If there is no cjsModuleInstance and is not generated source assume we are in a
+    // "modules/esm" context.
+    const entry = {
+      lineLengths: lineLengths(content),
+      data,
+      url,
+      sourceURL,
+    };
+    esmSourceMapCache.set(filename, entry);
+    if (sourceURL) {
+      esmSourceMapCache.set(sourceURL, entry);
     }
   }
 }

lib/internal/vm.js

@@ -0,0 +1,113 @@
+'use strict';
+
+const {
+  ArrayPrototypeForEach,
+} = primordials;
+
+const {
+  compileFunction,
+  isContext: _isContext,
+} = internalBinding('contextify');
+const {
+  validateArray,
+  validateBoolean,
+  validateBuffer,
+  validateFunction,
+  validateObject,
+  validateString,
+  validateUint32,
+} = require('internal/validators');
+const {
+  ERR_INVALID_ARG_TYPE,
+} = require('internal/errors').codes;
+
+function isContext(object) {
+  validateObject(object, 'object', { __proto__: null, allowArray: true });
+
+  return _isContext(object);
+}
+
+function internalCompileFunction(code, params, options) {
+  validateString(code, 'code');
+  if (params !== undefined) {
+    validateArray(params, 'params');
+    ArrayPrototypeForEach(params,
+                          (param, i) => validateString(param, `params[${i}]`));
+  }
+
+  const {
+    filename = '',
+    columnOffset = 0,
+    lineOffset = 0,
+    cachedData = undefined,
+    produceCachedData = false,
+    parsingContext = undefined,
+    contextExtensions = [],
+    importModuleDynamically,
+  } = options;
+
+  validateString(filename, 'options.filename');
+  validateUint32(columnOffset, 'options.columnOffset');
+  validateUint32(lineOffset, 'options.lineOffset');
+  if (cachedData !== undefined)
+    validateBuffer(cachedData, 'options.cachedData');
+  validateBoolean(produceCachedData, 'options.produceCachedData');
+  if (parsingContext !== undefined) {
+    if (
+      typeof parsingContext !== 'object' ||
+      parsingContext === null ||
+      !isContext(parsingContext)
+    ) {
+      throw new ERR_INVALID_ARG_TYPE(
+        'options.parsingContext',
+        'Context',
+        parsingContext
+      );
+    }
+  }
+  validateArray(contextExtensions, 'options.contextExtensions');
+  ArrayPrototypeForEach(contextExtensions, (extension, i) => {
+    const name = `options.contextExtensions[${i}]`;
+    validateObject(extension, name, { __proto__: null, nullable: true });
+  });
+
+  const result = compileFunction(
+    code,
+    filename,
+    lineOffset,
+    columnOffset,
+    cachedData,
+    produceCachedData,
+    parsingContext,
+    contextExtensions,
+    params
+  );
+
+  if (produceCachedData) {
+    result.function.cachedDataProduced = result.cachedDataProduced;
+  }
+
+  if (result.cachedData) {
+    result.function.cachedData = result.cachedData;
+  }
+
+  if (importModuleDynamically !== undefined) {
+    validateFunction(importModuleDynamically,
+                     'options.importModuleDynamically');
+    const { importModuleDynamicallyWrap } =
+      require('internal/vm/module');
+    const { callbackMap } = internalBinding('module_wrap');
+    const wrapped = importModuleDynamicallyWrap(importModuleDynamically);
+    const func = result.function;
+    callbackMap.set(result.cacheKey, {
+      importModuleDynamically: (s, _k, i) => wrapped(s, func, i),
+    });
+  }
+
+  return result;
+}
+
+module.exports = {
+  internalCompileFunction,
+  isContext,
+};