repl: display dynamic import variant in static import error messages

Enhance the REPL message for static import error message. ``` > import {foo, bar} from 'moo'; import {foo, bar} from 'moo'; ^^^^^^ Uncaught: SyntaxError: .* dynamic import: const {foo,bar} = await import('moo'); ```

Author: hemanth

lib/repl.js

@@ -58,6 +58,7 @@ const {
  ArrayPrototypeSome,
  ArrayPrototypeSort,
  ArrayPrototypeSplice,
+ ArrayPrototypeToString,
  ArrayPrototypeUnshift,
  Boolean,
  Error,
@@ -104,7 +105,12 @@ const {
 const {
  isIdentifierStart,
  isIdentifierChar,
+ parse: acornParse,
 } = require('internal/deps/acorn/acorn/dist/acorn');
+
+
+const acornWalk = require('internal/deps/acorn/acorn-walk/dist/walk');
+
 const {
  decorateErrorStack,
  isError,
@@ -223,6 +229,29 @@ module.paths = CJSModule._nodeModulePaths(module.filename);
 const writer = (obj) => inspect(obj, writer.options);
 writer.options = { ...inspect.defaultOptions, showProxy: true };
 
+// Converts static import statement to dynamic import statement
+const toDynamicImport = (codeLine) => {
+ let dynamicImportStatement = '';
+ let moduleName = '';
+ const toCamelCase = (str) => str.replace(/[-_](\w)/g, (_, c) => c.toUpperCase());
+ const ast = acornParse(codeLine, { sourceType: 'module', ecmaVersion: 'latest' });
+ acornWalk.ancestor(ast, {
+ ImportDeclaration: (node) => {
+ const importedModules = node.source.value;
+ const importedSpecifiers = node.specifiers.map((specifier) => specifier.local.name);
+ if (importedSpecifiers.length > 1) {
+ moduleName = `{${importedSpecifiers.join(',')}}`;
+ } else {
+ const formattedSpecifiers = importedSpecifiers.length ? ArrayPrototypeToString(importedSpecifiers) : '';
+ moduleName = toCamelCase(formattedSpecifiers || importedModules);
+ }
+ dynamicImportStatement += `const ${moduleName} = await import('${importedModules}');`;
+ },
+ });
+ return dynamicImportStatement;
+};
+
+
 function REPLServer(prompt,
  stream,
  eval_,
@@ -283,13 +312,13 @@ function REPLServer(prompt,
  get: pendingDeprecation ?
  deprecate(() => this.input,
  'repl.inputStream and repl.outputStream are deprecated. ' +
-  'Use repl.input and repl.output instead',
+ 'Use repl.input and repl.output instead',
  'DEP0141') :
  () => this.input,
  set: pendingDeprecation ?
  deprecate((val) => this.input = val,
  'repl.inputStream and repl.outputStream are deprecated. ' +
-  'Use repl.input and repl.output instead',
+ 'Use repl.input and repl.output instead',
  'DEP0141') :
  (val) => this.input = val,
  enumerable: false,
@@ -300,13 +329,13 @@ function REPLServer(prompt,
  get: pendingDeprecation ?
  deprecate(() => this.output,
  'repl.inputStream and repl.outputStream are deprecated. ' +
-  'Use repl.input and repl.output instead',
+ 'Use repl.input and repl.output instead',
  'DEP0141') :
  () => this.output,
  set: pendingDeprecation ?
  deprecate((val) => this.output = val,
  'repl.inputStream and repl.outputStream are deprecated. ' +
-  'Use repl.input and repl.output instead',
+ 'Use repl.input and repl.output instead',
  'DEP0141') :
  (val) => this.output = val,
  enumerable: false,
@@ -344,9 +373,9 @@ function REPLServer(prompt,
  // instance and that could trigger the `MaxListenersExceededWarning`.
  process.prependListener('newListener', (event, listener) => {
  if (event === 'uncaughtException' &&
-  process.domain &&
-  listener.name !== 'domainUncaughtExceptionClear' &&
-  domainSet.has(process.domain)) {
+ process.domain &&
+ listener.name !== 'domainUncaughtExceptionClear' &&
+ domainSet.has(process.domain)) {
  // Throw an error so that the event will not be added and the current
  // domain takes over. That way the user is notified about the error
  // and the current code evaluation is stopped, just as any other code
@@ -363,8 +392,8 @@ function REPLServer(prompt,
  const savedRegExMatches = ['', '', '', '', '', '', '', '', '', ''];
  const sep = '\u0000\u0000\u0000';
  const regExMatcher = new RegExp(`^${sep}(.*)${sep}(.*)${sep}(.*)${sep}(.*)` +
-  `${sep}(.*)${sep}(.*)${sep}(.*)${sep}(.*)` +
-  `${sep}(.*)$`);
+ `${sep}(.*)${sep}(.*)${sep}(.*)${sep}(.*)` +
+ `${sep}(.*)$`);
 
  eval_ = eval_ || defaultEval;
 
@@ -417,7 +446,7 @@ function REPLServer(prompt,
  // an expression. Note that if the above condition changes,
  // lib/internal/repl/utils.js needs to be changed to match.
  if (RegExpPrototypeExec(/^\s*{/, code) !== null &&
-  RegExpPrototypeExec(/;\s*$/, code) === null) {
+ RegExpPrototypeExec(/;\s*$/, code) === null) {
  code = `(${StringPrototypeTrim(code)})\n`;
  wrappedCmd = true;
  }
@@ -492,7 +521,7 @@ function REPLServer(prompt,
  while (true) {
  try {
  if (self.replMode === module.exports.REPL_MODE_STRICT &&
-  RegExpPrototypeExec(/^\s*$/, code) === null) {
+ RegExpPrototypeExec(/^\s*$/, code) === null) {
  // "void 0" keeps the repl from returning "use strict" as the result
  // value for statements and declarations that don't return a value.
  code = `'use strict'; void 0;\n${code}`;
@@ -684,7 +713,7 @@ function REPLServer(prompt,
  'module';
  if (StringPrototypeIncludes(e.message, importErrorStr)) {
  e.message = 'Cannot use import statement inside the Node.js ' +
- 'REPL, alternatively use dynamic import';
+ 'REPL, alternatively use dynamic import: ' + toDynamicImport(self.lines.at(-1));
  e.stack = SideEffectFreeRegExpPrototypeSymbolReplace(
  /SyntaxError:.*\n/,
  e.stack,
@@ -712,7 +741,7 @@ function REPLServer(prompt,
  }
 
  if (options[kStandaloneREPL] &&
-  process.listenerCount('uncaughtException') !== 0) {
+ process.listenerCount('uncaughtException') !== 0) {
  process.nextTick(() => {
  process.emit('uncaughtException', e);
  self.clearBufferedCommand();
@@ -729,7 +758,7 @@ function REPLServer(prompt,
  errStack = '';
  ArrayPrototypeForEach(lines, (line) => {
  if (!matched &&
-  RegExpPrototypeExec(/^\[?([A-Z][a-z0-9_]*)*Error/, line) !== null) {
+ RegExpPrototypeExec(/^\[?([A-Z][a-z0-9_]*)*Error/, line) !== null) {
  errStack += writer.options.breakLength >= line.length ?
  `Uncaught ${line}` :
  `Uncaught:\n${line}`;
@@ -875,8 +904,8 @@ function REPLServer(prompt,
  // display next prompt and return.
  if (trimmedCmd) {
  if (StringPrototypeCharAt(trimmedCmd, 0) === '.' &&
-  StringPrototypeCharAt(trimmedCmd, 1) !== '.' &&
-  NumberIsNaN(NumberParseFloat(trimmedCmd))) {
+ StringPrototypeCharAt(trimmedCmd, 1) !== '.' &&
+ NumberIsNaN(NumberParseFloat(trimmedCmd))) {
  const matches = RegExpPrototypeExec(/^\.([^\s]+)\s*(.*)$/, trimmedCmd);
  const keyword = matches && matches[1];
  const rest = matches && matches[2];
@@ -901,10 +930,10 @@ function REPLServer(prompt,
  ReflectApply(_memory, self, [cmd]);
 
  if (e && !self[kBufferedCommandSymbol] &&
-  StringPrototypeStartsWith(StringPrototypeTrim(cmd), 'npm ')) {
+ StringPrototypeStartsWith(StringPrototypeTrim(cmd), 'npm ')) {
  self.output.write('npm should be run outside of the ' +
-  'Node.js REPL, in your normal shell.\n' +
-  '(Press Ctrl+D to exit.)\n');
+ 'Node.js REPL, in your normal shell.\n' +
+ '(Press Ctrl+D to exit.)\n');
  self.displayPrompt();
  return;
  }
@@ -929,11 +958,11 @@ function REPLServer(prompt,
 
  // If we got any output - print it (if no error)
  if (!e &&
-  // When an invalid REPL command is used, error message is printed
-  // immediately. We don't have to print anything else. So, only when
-  // the second argument to this function is there, print it.
-  arguments.length === 2 &&
-  (!self.ignoreUndefined || ret !== undefined)) {
+ // When an invalid REPL command is used, error message is printed
+ // immediately. We don't have to print anything else. So, only when
+ // the second argument to this function is there, print it.
+ arguments.length === 2 &&
+ (!self.ignoreUndefined || ret !== undefined)) {
  if (!self.underscoreAssigned) {
  self.last = ret;
  }
@@ -984,7 +1013,7 @@ function REPLServer(prompt,
  if (!self.editorMode || !self.terminal) {
  // Before exiting, make sure to clear the line.
  if (key.ctrl && key.name === 'd' &&
-  self.cursor === 0 && self.line.length === 0) {
+ self.cursor === 0 && self.line.length === 0) {
  self.clearLine();
  }
  clearPreview(key);
@@ -1181,7 +1210,7 @@ const importRE = /\bimport\s*\(\s*['"`](([\w@./:-]+\/)?(?:[\w@./:-]*))(?![^'"`])
 const requireRE = /\brequire\s*\(\s*['"`](([\w@./:-]+\/)?(?:[\w@./:-]*))(?![^'"`])$/;
 const fsAutoCompleteRE = /fs(?:\.promises)?\.\s*[a-z][a-zA-Z]+\(\s*["'](.*)/;
 const simpleExpressionRE =
-  /(?:[\w$'"`[{(](?:\w|\$|['"`\]})])*\??\.)*[a-zA-Z_$](?:\w|\$)*\??\.?$/;
+ /(?:[\w$'"`[{(](?:\w|\$|['"`\]})])*\??\.)*[a-zA-Z_$](?:\w|\$)*\??\.?$/;
 const versionedFileNamesRe = /-\d+\.\d+/;
 
 function isIdentifier(str) {
@@ -1337,15 +1366,15 @@ function complete(line, callback) {
  const dirents = gracefulReaddir(dir, { withFileTypes: true }) || [];
  ArrayPrototypeForEach(dirents, (dirent) => {
  if (RegExpPrototypeExec(versionedFileNamesRe, dirent.name) !== null ||
-  dirent.name === '.npm') {
+ dirent.name === '.npm') {
  // Exclude versioned names that 'npm' installs.
  return;
  }
  const extension = path.extname(dirent.name);
  const base = StringPrototypeSlice(dirent.name, 0, -extension.length);
  if (!dirent.isDirectory()) {
  if (StringPrototypeIncludes(extensions, extension) &&
-  (!subdir || base !== 'index')) {
+ (!subdir || base !== 'index')) {
  ArrayPrototypePush(group, `${subdir}${base}`);
  }
  return;
@@ -1398,7 +1427,7 @@ function complete(line, callback) {
  ArrayPrototypeForEach(dirents, (dirent) => {
  const { name } = dirent;
  if (RegExpPrototypeExec(versionedFileNamesRe, name) !== null ||
-  name === '.npm') {
+ name === '.npm') {
  // Exclude versioned names that 'npm' installs.
  return;
  }
@@ -1431,20 +1460,20 @@ function complete(line, callback) {
 
  ArrayPrototypePush(completionGroups, _builtinLibs, nodeSchemeBuiltinLibs);
  } else if ((match = RegExpPrototypeExec(fsAutoCompleteRE, line)) !== null &&
-  this.allowBlockingCompletions) {
+ this.allowBlockingCompletions) {
  ({ 0: completionGroups, 1: completeOn } = completeFSFunctions(match));
- // Handle variable member lookup.
- // We support simple chained expressions like the following (no function
- // calls, etc.). That is for simplicity and also because we *eval* that
- // leading expression so for safety (see WARNING above) don't want to
- // eval function calls.
- //
- // foo.bar<|> # completions for 'foo' with filter 'bar'
- // spam.eggs.<|> # completions for 'spam.eggs' with filter ''
- // foo<|> # all scope vars with filter 'foo'
- // foo.<|> # completions for 'foo' with filter ''
+  // Handle variable member lookup.
+  // We support simple chained expressions like the following (no function
+  // calls, etc.). That is for simplicity and also because we *eval* that
+  // leading expression so for safety (see WARNING above) don't want to
+  // eval function calls.
+  //
+  // foo.bar<|> # completions for 'foo' with filter 'bar'
+  // spam.eggs.<|> # completions for 'spam.eggs' with filter ''
+  // foo<|> # all scope vars with filter 'foo'
+  // foo.<|> # completions for 'foo' with filter ''
  } else if (line.length === 0 ||
-  RegExpPrototypeExec(/\w|\.|\$/, line[line.length - 1]) !== null) {
+ RegExpPrototypeExec(/\w|\.|\$/, line[line.length - 1]) !== null) {
  const { 0: match } = RegExpPrototypeExec(simpleExpressionRE, line) || [''];
  if (line.length !== 0 && !match) {
  completionGroupsLoaded();
@@ -1495,7 +1524,7 @@ function complete(line, callback) {
  try {
  let p;
  if ((typeof obj === 'object' && obj !== null) ||
-  typeof obj === 'function') {
+ typeof obj === 'function') {
  memberGroups.push(filteredOwnPropertyNames(obj));
  p = ObjectGetPrototypeOf(obj);
  } else {

test/parallel/test-repl.js

@@ -818,7 +818,41 @@ const tcpTests = [
  kArrow,
  '',
  'Uncaught:',
- /^SyntaxError: .* dynamic import/,
+ 'SyntaxError: Cannot use import statement inside the Node.js REPL, \
+alternatively use dynamic import: const comeOn = await import(\'fhqwhgads\');',
+ ]
+ },
+ {
+ send: 'import { export1, export2 } from "module-name"',
+ expect: [
+ kSource,
+ kArrow,
+ '',
+ 'Uncaught:',
+ 'SyntaxError: Cannot use import statement inside the Node.js REPL, \
+alternatively use dynamic import: const {export1,export2} = await import(\'module-name\');',
+ ]
+ },
+ {
+ send: 'import * as name from "module-name";',
+ expect: [
+ kSource,
+ kArrow,
+ '',
+ 'Uncaught:',
+ 'SyntaxError: Cannot use import statement inside the Node.js REPL, \
+alternatively use dynamic import: const name = await import(\'module-name\');',
+ ]
+ },
+ {
+ send: 'import "module-name";',
+ expect: [
+ kSource,
+ kArrow,
+ '',
+ 'Uncaught:',
+ 'SyntaxError: Cannot use import statement inside the Node.js REPL, \
+alternatively use dynamic import: const moduleName = await import(\'module-name\');',
  ]
  },
 ];