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module: use synchronous hooks for preparsing in import(cjs)
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PR-URL: #55698
Reviewed-By: Geoffrey Booth <webadmin@geoffreybooth.com>
Reviewed-By: Chengzhong Wu <legendecas@gmail.com>
Reviewed-By: Guy Bedford <guybedford@gmail.com>
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@joyeecheung @nodejs-github-bot
joyeecheung authored and nodejs-github-bot committed Dec 9, 2024
1 parent e859646 commit 1215a8b
Showing 1 changed file with 34 additions and 31 deletions.
65 changes: 34 additions & 31 deletions lib/internal/modules/esm/translators.js
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Original file line number Diff line number Diff line change
Expand Up @@ -26,7 +26,7 @@ const {
const { BuiltinModule } = require('internal/bootstrap/realm');
const assert = require('internal/assert');
const { readFileSync } = require('fs');
const { dirname, extname, isAbsolute } = require('path');
const { dirname, extname } = require('path');
const {
assertBufferSource,
loadBuiltinModule,
Expand All @@ -42,6 +42,9 @@ const {
kModuleSource,
kModuleExport,
kModuleExportNames,
findLongestRegisteredExtension,
resolveForCJSWithHooks,
loadSourceForCJSWithHooks,
} = require('internal/modules/cjs/loader');
const { fileURLToPath, pathToFileURL, URL } = require('internal/url');
let debug = require('internal/util/debuglog').debuglog('esm', (fn) => {
Expand Down Expand Up @@ -171,17 +174,18 @@ const cjsCache = new SafeMap();
* @param {string} url - The URL of the module.
* @param {string} source - The source code of the module.
* @param {boolean} isMain - Whether the module is the main module.
* @param {string} format - Format of the module.
* @param {typeof loadCJSModule} [loadCJS=loadCJSModule] - The function to load the CommonJS module.
* @returns {ModuleWrap} The ModuleWrap object for the CommonJS module.
*/
function createCJSModuleWrap(url, source, isMain, loadCJS = loadCJSModule) {
function createCJSModuleWrap(url, source, isMain, format, loadCJS = loadCJSModule) {
debug(`Translating CJSModule ${url}`);

const filename = urlToFilename(url);
// In case the source was not provided by the `load` step, we need fetch it now.
source = stringify(source ?? getSource(new URL(url)).source);

const { exportNames, module } = cjsPreparseModuleExports(filename, source);
const { exportNames, module } = cjsPreparseModuleExports(filename, source, isMain, format);
cjsCache.set(url, module);

const wrapperNames = [...exportNames, 'module.exports'];
Expand Down Expand Up @@ -228,7 +232,7 @@ function createCJSModuleWrap(url, source, isMain, loadCJS = loadCJSModule) {
translators.set('commonjs-sync', function requireCommonJS(url, source, isMain) {
initCJSParseSync();

return createCJSModuleWrap(url, source, isMain, (module, source, url, filename, isMain) => {
return createCJSModuleWrap(url, source, isMain, 'commonjs', (module, source, url, filename, isMain) => {
assert(module === CJSModule._cache[filename]);
wrapModuleLoad(filename, null, isMain);
});
Expand All @@ -240,7 +244,7 @@ translators.set('require-commonjs', (url, source, isMain) => {
initCJSParseSync();
assert(cjsParse);

return createCJSModuleWrap(url, source);
return createCJSModuleWrap(url, source, isMain, 'commonjs');
});

// Handle CommonJS modules referenced by `require` calls.
Expand All @@ -249,7 +253,7 @@ translators.set('require-commonjs-typescript', (url, source, isMain) => {
emitExperimentalWarning('Type Stripping');
assert(cjsParse);
const code = stripTypeScriptModuleTypes(stringify(source), url);
return createCJSModuleWrap(url, code);
return createCJSModuleWrap(url, code, isMain, 'commonjs-typescript');
});

// Handle CommonJS modules referenced by `import` statements or expressions,
Expand All @@ -273,16 +277,17 @@ translators.set('commonjs', function commonjsStrategy(url, source, isMain) {
} catch {
// Continue regardless of error.
}
return createCJSModuleWrap(url, source, isMain, cjsLoader);
return createCJSModuleWrap(url, source, isMain, 'commonjs', cjsLoader);
});

/**
* Pre-parses a CommonJS module's exports and re-exports.
* @param {string} filename - The filename of the module.
* @param {string} [source] - The source code of the module.
* @param {boolean} isMain - Whether it is pre-parsing for the entry point.
* @param {string} format
*/
function cjsPreparseModuleExports(filename, source) {
// TODO: Do we want to keep hitting the user mutable CJS loader here?
function cjsPreparseModuleExports(filename, source, isMain, format) {
let module = CJSModule._cache[filename];
if (module && module[kModuleExportNames] !== undefined) {
return { module, exportNames: module[kModuleExportNames] };
Expand All @@ -293,10 +298,15 @@ function cjsPreparseModuleExports(filename, source) {
module.filename = filename;
module.paths = CJSModule._nodeModulePaths(module.path);
module[kIsCachedByESMLoader] = true;
module[kModuleSource] = source;
CJSModule._cache[filename] = module;
}

if (source === undefined) {
({ source } = loadSourceForCJSWithHooks(module, filename, format));
}
module[kModuleSource] = source;

debug(`Preparsing exports of ${filename}`);
let exports, reexports;
try {
({ exports, reexports } = cjsParse(source || ''));
Expand All @@ -310,34 +320,27 @@ function cjsPreparseModuleExports(filename, source) {
// Set first for cycles.
module[kModuleExportNames] = exportNames;

// If there are any re-exports e.g. `module.exports = { ...require(...) }`,
// pre-parse the dependencies to find transitively exported names.
if (reexports.length) {
module.filename = filename;
module.paths = CJSModule._nodeModulePaths(module.path);
module.filename ??= filename;
module.paths ??= CJSModule._nodeModulePaths(dirname(filename));

for (let i = 0; i < reexports.length; i++) {
debug(`Preparsing re-exports of '${filename}'`);
const reexport = reexports[i];
let resolved;
let format;
try {
// TODO: this should be calling the `resolve` hook chain instead.
// Doing so would mean dropping support for CJS in the loader thread, as
// this call needs to be sync from the perspective of the main thread,
// which we can do via HooksProxy and Atomics, but we can't do within
// the loaders thread. Until this is done, the lexer will use the
// monkey-patchable CJS loader to get the path to the module file to
// load (which may or may not be aligned with the URL that the `resolve`
// hook have returned).
resolved = CJSModule._resolveFilename(reexport, module);
} catch {
({ format, filename: resolved } = resolveForCJSWithHooks(reexport, module, false));
} catch (e) {
debug(`Failed to resolve '${reexport}', skipping`, e);
continue;
}
// TODO: this should be calling the `load` hook chain and check if it returns
// `format: 'commonjs'` instead of relying on file extensions.
const ext = extname(resolved);
if ((ext === '.js' || ext === '.cjs' || !CJSModule._extensions[ext]) &&
isAbsolute(resolved)) {
// TODO: this should be calling the `load` hook chain to get the source
// (and fallback to reading the FS only if the source is nullish).
const source = readFileSync(resolved, 'utf-8');
const { exportNames: reexportNames } = cjsPreparseModuleExports(resolved, source);

if (format === 'commonjs' ||
(!BuiltinModule.normalizeRequirableId(resolved) && findLongestRegisteredExtension(resolved) === '.js')) {
const { exportNames: reexportNames } = cjsPreparseModuleExports(resolved, undefined, false, format);
for (const name of reexportNames) {
exportNames.add(name);
}
Expand Down

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