module: support eval with ts syntax detection

Author: marco-ippolito

doc/api/cli.md

@@ -1370,8 +1370,15 @@ added: v12.0.0
 -->
 
 This configures Node.js to interpret `--eval` or `STDIN` input as CommonJS or
-as an ES module. Valid values are `"commonjs"` or `"module"`. The default is
-`"commonjs"`.
+as an ES module. Valid values are `"commonjs"`, `"module"`, `"module-typescript"` and `"commonjs-typescript"`.
+The `"-typescript"` values are available only in combination with the flag `--experimental-strip-types`.
+The default is `"commonjs"`.
+
+If `--experimental-strip-types` is enabled and `--input-type`is not provided,
+Node.js will first try to run the code as JavaScript,
+then it will try to run the code as TypeScript.
+When using TypeScript, the `--input-type=type` flag should always be used,
+to reduce the overhead of multiple syntax detections.
 
 The REPL does not support this option. Usage of `--input-type=module` with
 [`--print`][] will throw an error, as `--print` does not support ES module

lib/internal/main/eval_string.js

@@ -13,28 +13,34 @@ const {
   prepareMainThreadExecution,
   markBootstrapComplete,
 } = require('internal/process/pre_execution');
-const { evalModuleEntryPoint, evalScript } = require('internal/process/execution');
+const {
+  evalModuleEntryPoint,
+  evalTypeScript,
+  parseAndEvalCommonjsTypeScript,
+  parseAndEvalModuleTypeScript,
+  evalScript,
+} = require('internal/process/execution');
 const { addBuiltinLibsToObject } = require('internal/modules/helpers');
-const { stripTypeScriptModuleTypes } = require('internal/modules/typescript');
 const { getOptionValue } = require('internal/options');
 
 prepareMainThreadExecution();
 addBuiltinLibsToObject(globalThis, '<eval>');
 markBootstrapComplete();
 
 const code = getOptionValue('--eval');
-const source = getOptionValue('--experimental-strip-types') ?
-  stripTypeScriptModuleTypes(code) :
-  code;
 
 const print = getOptionValue('--print');
 const shouldLoadESM = getOptionValue('--import').length > 0 || getOptionValue('--experimental-loader').length > 0;
-if (getOptionValue('--input-type') === 'module') {
-  evalModuleEntryPoint(source, print);
+const inputType = getOptionValue('--input-type');
+const tsEnabled = getOptionValue('--experimental-strip-types');
+if (inputType === 'module') {
+  evalModuleEntryPoint(code, print);
+} else if (inputType === 'module-typescript' && tsEnabled) {
+  parseAndEvalModuleTypeScript(code, print);
 } else {
   // For backward compatibility, we want the identifier crypto to be the
   // `node:crypto` module rather than WebCrypto.
-  const isUsingCryptoIdentifier = RegExpPrototypeExec(/\bcrypto\b/, source) !== null;
+  const isUsingCryptoIdentifier = RegExpPrototypeExec(/\bcrypto\b/, code) !== null;
   const shouldDefineCrypto = isUsingCryptoIdentifier && internalBinding('config').hasOpenSSL;
 
   if (isUsingCryptoIdentifier && !shouldDefineCrypto) {
@@ -49,11 +55,24 @@ if (getOptionValue('--input-type') === 'module') {
     };
     ObjectDefineProperty(object, name, { __proto__: null, set: setReal });
   }
-  evalScript('[eval]',
-             shouldDefineCrypto ? (
-               print ? `let crypto=require("node:crypto");{${source}}` : `(crypto=>{{${source}}})(require('node:crypto'))`
-             ) : source,
-             getOptionValue('--inspect-brk'),
-             print,
-             shouldLoadESM);
+
+  let evalFunction;
+  if (inputType === 'commonjs') {
+    evalFunction = evalScript;
+  } else if (inputType === 'commonjs-typescript' && tsEnabled) {
+    evalFunction = parseAndEvalCommonjsTypeScript;
+  } else if (tsEnabled) {
+    evalFunction = evalTypeScript;
+  } else {
+    // Default to commonjs.
+    evalFunction = evalScript;
+  }
+
+  evalFunction('[eval]',
+               shouldDefineCrypto ? (
+                 print ? `let crypto=require("node:crypto");{${code}}` : `(crypto=>{{${code}}})(require('node:crypto'))`
+               ) : code,
+               getOptionValue('--inspect-brk'),
+               print,
+               shouldLoadESM);
 }

lib/internal/modules/cjs/loader.js

@@ -449,7 +449,6 @@ function initializeCJS() {
 
   const tsEnabled = getOptionValue('--experimental-strip-types');
   if (tsEnabled) {
-    emitExperimentalWarning('Type Stripping');
     Module._extensions['.cts'] = loadCTS;
     Module._extensions['.ts'] = loadTS;
   }

lib/internal/modules/esm/translators.js

@@ -250,7 +250,6 @@ translators.set('require-commonjs', (url, source, isMain) => {
 // Handle CommonJS modules referenced by `require` calls.
 // This translator function must be sync, as `require` is sync.
 translators.set('require-commonjs-typescript', (url, source, isMain) => {
-  emitExperimentalWarning('Type Stripping');
   assert(cjsParse);
   const code = stripTypeScriptModuleTypes(stringify(source), url);
   return createCJSModuleWrap(url, code, isMain, 'commonjs-typescript');
@@ -464,7 +463,6 @@ translators.set('wasm', async function(url, source) {
 
 // Strategy for loading a commonjs TypeScript module
 translators.set('commonjs-typescript', function(url, source) {
-  emitExperimentalWarning('Type Stripping');
   assertBufferSource(source, true, 'load');
   const code = stripTypeScriptModuleTypes(stringify(source), url);
   debug(`Translating TypeScript ${url}`);
@@ -473,7 +471,6 @@ translators.set('commonjs-typescript', function(url, source) {
 
 // Strategy for loading an esm TypeScript module
 translators.set('module-typescript', function(url, source) {
-  emitExperimentalWarning('Type Stripping');
   assertBufferSource(source, true, 'load');
   const code = stripTypeScriptModuleTypes(stringify(source), url);
   debug(`Translating TypeScript ${url}`);

lib/internal/modules/typescript.js

@@ -112,9 +112,13 @@ function processTypeScriptCode(code, options) {
  * It is used by internal loaders.
  * @param {string} source TypeScript code to parse.
  * @param {string} filename The filename of the source code.
+ * @param {boolean} emitWarning Whether to emit a warning.
  * @returns {TransformOutput} The stripped TypeScript code.
  */
-function stripTypeScriptModuleTypes(source, filename) {
+function stripTypeScriptModuleTypes(source, filename, emitWarning = true) {
+  if (emitWarning) {
+    emitExperimentalWarning('Type Stripping');
+  }
   assert(typeof source === 'string');
   if (isUnderNodeModules(filename)) {
     throw new ERR_UNSUPPORTED_NODE_MODULES_TYPE_STRIPPING(filename);

lib/internal/process/execution.js

@@ -1,7 +1,10 @@
 'use strict';
 
 const {
+  ArrayPrototypeJoin,
+  ArrayPrototypeSplice,
   RegExpPrototypeExec,
+  StringPrototypeSplit,
   Symbol,
   globalThis,
 } = primordials;
@@ -17,6 +20,7 @@ const {
 } = require('internal/errors');
 const { pathToFileURL } = require('internal/url');
 const { exitCodes: { kGenericUserError } } = internalBinding('errors');
+const { stripTypeScriptModuleTypes } = require('internal/modules/typescript');
 
 const {
   executionAsyncId,
@@ -32,6 +36,7 @@ const { getOptionValue } = require('internal/options');
 const {
   makeContextifyScript, runScriptInThisContext,
 } = require('internal/vm');
+const { emitExperimentalWarning } = require('internal/util');
 // shouldAbortOnUncaughtToggle is a typed array for faster
 // communication with JS.
 const { shouldAbortOnUncaughtToggle } = internalBinding('util');
@@ -84,6 +89,9 @@ function evalScript(name, body, breakFirstLine, print, shouldLoadESM = false) {
   if (getOptionValue('--experimental-detect-module') &&
     getOptionValue('--input-type') === '' &&
     containsModuleSyntax(body, name, null, 'no CJS variables')) {
+    if (getOptionValue('--experimental-strip-types')) {
+      return evalTypeScriptModuleEntryPoint(body, print);
+    }
     return evalModuleEntryPoint(body, print);
   }
 
@@ -238,10 +246,120 @@ function readStdin(callback) {
   });
 }
 
+/**
+ *
+ * Adds the TS message to the error stack
+ * At the 3rd line of the stack, the message is added
+ * @param {Error} originalStack the stack to decorate
+ * @param {string} newMessage the message to add to the error stack
+ * @returns {void}
+ */
+function decorateCJSErrorWithTSMessage(originalStack, newMessage) {
+  const lines = StringPrototypeSplit(originalStack, '\n');
+  ArrayPrototypeSplice(lines, 3, 0, newMessage);
+  return ArrayPrototypeJoin(lines, '\n');
+}
+
+/**
+ *
+ * Wrapper of evalScript
+ *
+ * This function wraps the evaluation of the source code in a try-catch block.
+ * If the source code fails to be evaluated, it will retry evaluating the source code
+ * with the TypeScript parser.
+ *
+ * If the source code fails to be evaluated with the TypeScript parser,
+ * it will rethrow the original error, adding the TypeScript error message to the stack.
+ *
+ * This way we don't change the behavior of the code, but we provide a better error message
+ * in case of a typescript error.
+ */
+function evalTypeScript(name, source, breakFirstLine, print, shouldLoadESM = false) {
+  try {
+    evalScript(name, source, breakFirstLine, print, shouldLoadESM);
+  } catch (originalError) {
+    try {
+      const strippedSource = stripTypeScriptModuleTypes(source, name, false);
+      evalScript(name, strippedSource, breakFirstLine, print, shouldLoadESM);
+      // Emit the experimental warning after the code was successfully evaluated.
+      emitExperimentalWarning('Type Stripping');
+    } catch (tsError) {
+      if (tsError.code === 'ERR_INVALID_TYPESCRIPT_SYNTAX') {
+        originalError.stack = decorateCJSErrorWithTSMessage(originalError.stack, tsError.message);
+      }
+      throw originalError;
+    }
+  }
+}
+
+/**
+ * Wrapper of evalModuleEntryPoint
+ *
+ * This function wraps the evaluation of the source code in a try-catch block.
+ * If the source code fails to be evaluated, it will retry evaluating the source code
+ * with the TypeScript parser.
+ *
+ */
+function evalTypeScriptModuleEntryPoint(source, print) {
+  if (print) {
+    throw new ERR_EVAL_ESM_CANNOT_PRINT();
+  }
+
+  RegExpPrototypeExec(/^/, ''); // Necessary to reset RegExp statics before user code runs.
+
+  return require('internal/modules/run_main').runEntryPointWithESMLoader(
+    async (loader) => {
+      try {
+        // Await here to catch the error and rethrow it with the typescript error message.
+        return await loader.eval(source, getEvalModuleUrl(), true);
+      } catch (originalError) {
+        try {
+          const url = getEvalModuleUrl();
+          const strippedSource = stripTypeScriptModuleTypes(source, url, false);
+          const result = await loader.eval(strippedSource, url, true);
+          // Emit the experimental warning after the code was successfully evaluated.
+          emitExperimentalWarning('Type Stripping');
+          return result;
+        } catch (tsError) {
+          if (tsError.code === 'ERR_INVALID_TYPESCRIPT_SYNTAX') {
+            originalError.stack = `${tsError.message}\n\n${originalError.stack}`;
+          }
+          throw originalError;
+        }
+      }
+    },
+  );
+};
+
+/**
+ *
+ * Function used to shortcut when `--input-type=module-typescript` is set.
+ * @param {string} source
+ * @param {boolean} print
+ */
+function parseAndEvalModuleTypeScript(source, print) {
+  // We know its a TypeScript module, we can safely emit the experimental warning.
+  const strippedSource = stripTypeScriptModuleTypes(source, getEvalModuleUrl());
+  evalModuleEntryPoint(strippedSource, print);
+}
+
+/**
+ * Function used to shortcut when `--input-type=commonjs-typescript` is set
+ * See evalScript signature
+ */
+function parseAndEvalCommonjsTypeScript(name, source, breakFirstLine, print, shouldLoadESM = false) {
+  // We know its a TypeScript module, we can safely emit the experimental warning.
+  const strippedSource = stripTypeScriptModuleTypes(source, getEvalModuleUrl());
+  evalScript(name, strippedSource, breakFirstLine, print, shouldLoadESM);
+}
+
 module.exports = {
+  parseAndEvalCommonjsTypeScript,
+  parseAndEvalModuleTypeScript,
   readStdin,
   tryGetCwd,
   evalModuleEntryPoint,
+  evalTypeScript,
   evalScript,
   onGlobalUncaughtException: createOnGlobalUncaughtException(),
   setUncaughtExceptionCaptureCallback,

src/node_options.cc

@@ -108,8 +108,12 @@ void PerIsolateOptions::CheckOptions(std::vector<std::string>* errors,
 void EnvironmentOptions::CheckOptions(std::vector<std::string>* errors,
                                       std::vector<std::string>* argv) {
   if (!input_type.empty()) {
-    if (input_type != "commonjs" && input_type != "module") {
-      errors->push_back("--input-type must be \"module\" or \"commonjs\"");
+    if (input_type != "commonjs" && input_type != "module" &&
+        input_type != "commonjs-typescript" &&
+        input_type != "module-typescript") {
+      errors->push_back(
+          "--input-type must be \"module\","
+          "\"commonjs\", \"module-typescript\" or \"commonjs-typescript\"");
     }
   }