repl: improve repl preview

lib/internal/modules/cjs/helpers.js

@@ -2,6 +2,7 @@
 
 const {
   ObjectDefineProperty,
+  ObjectPrototypeHasOwnProperty,
   SafeMap,
 } = primordials;
 const {
@@ -109,55 +110,17 @@ function stripBOM(content) {
   return content;
 }
 
-const builtinLibs = [
-  'assert',
-  'async_hooks',
-  'buffer',
-  'child_process',
-  'cluster',
-  'crypto',
-  'dgram',
-  'dns',
-  'domain',
-  'events',
-  'fs',
-  'http',
-  'http2',
-  'https',
-  'net',
-  'os',
-  'path',
-  'perf_hooks',
-  'punycode',
-  'querystring',
-  'readline',
-  'repl',
-  'stream',
-  'string_decoder',
-  'tls',
-  'trace_events',
-  'tty',
-  'url',
-  'util',
-  'v8',
-  'vm',
-  'worker_threads',
-  'zlib',
-];
-
-if (internalBinding('config').experimentalWasi) {
-  builtinLibs.push('wasi');
-  builtinLibs.sort();
-}
-
-if (typeof internalBinding('inspector').open === 'function') {
-  builtinLibs.push('inspector');
-  builtinLibs.sort();
-}
-
 function addBuiltinLibsToObject(object) {
   // Make built-in modules available directly (loaded lazily).
-  builtinLibs.forEach((name) => {
+  const { builtinModules } = require('internal/modules/cjs/loader').Module;
+  builtinModules.forEach((name) => {
+    // Neither add underscored modules, nor ones that contain slashes (e.g.,
+    // 'fs/promises') or ones that are already defined.
+    if (name.startsWith('_') ||
+        name.includes('/') ||
+        ObjectPrototypeHasOwnProperty(object, name)) {
+      return;
+    }
     // Goals of this mechanism are:
     // - Lazy loading of built-in modules
     // - Having all built-in modules available as non-enumerable properties
@@ -203,7 +166,6 @@ function normalizeReferrerURL(referrer) {
 
 module.exports = {
   addBuiltinLibsToObject,
-  builtinLibs,
   loadNativeModule,
   makeRequireFunction,
   normalizeReferrerURL,

lib/internal/repl/utils.js

@@ -48,6 +48,8 @@ const previewOptions = {
   showHidden: false
 };
 
+const REPL_MODE_STRICT = Symbol('repl-strict');
+
 // If the error is that we've unexpectedly ended the input,
 // then let the user try to recover by adding more input.
 // Note: `e` (the original exception) is not used by the current implementation,
@@ -136,8 +138,12 @@ function setupPreview(repl, contextSymbol, bufferSymbol, active) {
   let previewCompletionCounter = 0;
   let completionPreview = null;
 
+  let hasCompletions = false;
+
   let wrapped = false;
 
+  let escaped = null;
+
   function getPreviewPos() {
     const displayPos = repl._getDisplayPos(`${repl._prompt}${repl.line}`);
     const cursorPos = repl.line.length !== repl.cursor ?
@@ -146,7 +152,13 @@ function setupPreview(repl, contextSymbol, bufferSymbol, active) {
     return { displayPos, cursorPos };
   }
 
-  const clearPreview = () => {
+  function isCursorAtInputEnd() {
+    const { cursorPos, displayPos } = getPreviewPos();
+    return cursorPos.rows === displayPos.rows &&
+           cursorPos.cols === displayPos.cols;
+  }
+
+  const clearPreview = (key) => {
     if (inputPreview !== null) {
       const { displayPos, cursorPos } = getPreviewPos();
       const rows = displayPos.rows - cursorPos.rows + 1;
@@ -179,8 +191,23 @@ function setupPreview(repl, contextSymbol, bufferSymbol, active) {
         cursorTo(repl.output, pos.cursorPos.cols);
         moveCursor(repl.output, 0, -rows);
       }
+      if (!key.ctrl && !key.shift) {
+        if (key.name === 'escape') {
+          if (escaped === null && key.meta) {
+            escaped = repl.line;
+          }
+        } else if ((key.name === 'return' || key.name === 'enter') &&
+                   !key.meta &&
+                   escaped !== repl.line &&
+                   isCursorAtInputEnd()) {
+          repl._insertString(completionPreview);
+        }
+      }
       completionPreview = null;
     }
+    if (escaped !== repl.line) {
+      escaped = null;
+    }
   };
 
   function showCompletionPreview(line, insertPreview) {
@@ -206,6 +233,8 @@ function setupPreview(repl, contextSymbol, bufferSymbol, active) {
         return;
       }
 
+      hasCompletions = true;
+
       // If there is a common prefix to all matches, then apply that portion.
       const completions = rawCompletions.filter((e) => e);
       const prefix = commonPrefix(completions);
@@ -242,6 +271,12 @@ function setupPreview(repl, contextSymbol, bufferSymbol, active) {
     });
   }
 
+  function isInStrictMode(repl) {
+    return repl.replMode === REPL_MODE_STRICT || process.execArgv
+      .map((e) => e.toLowerCase().replace(/_/g, '-'))
+      .includes('--use-strict');
+  }
+
   // This returns a code preview for arbitrary input code.
   function getInputPreview(input, callback) {
     // For similar reasons as `defaultEval`, wrap expressions starting with a
@@ -269,8 +304,11 @@ function setupPreview(repl, contextSymbol, bufferSymbol, active) {
         // may be inspected.
         } else if (preview.exceptionDetails &&
                    (result.className === 'EvalError' ||
-                     result.className === 'SyntaxError' ||
-                     result.className === 'ReferenceError')) {
+                    result.className === 'SyntaxError' ||
+                    // Report ReferenceError in case the strict mode is active
+                    // for input that has no completions.
+                    (result.className === 'ReferenceError' &&
+                     (hasCompletions || !isInStrictMode(repl))))) {
           callback(null, null);
         } else if (result.objectId) {
           // The writer options might change and have influence on the inspect
@@ -316,14 +354,9 @@ function setupPreview(repl, contextSymbol, bufferSymbol, active) {
       return;
     }
 
+    hasCompletions = false;
+
     // Add the autocompletion preview.
-    // TODO(BridgeAR): Trigger the input preview after the completion preview.
-    // That way it's possible to trigger the input prefix including the
-    // potential completion suffix. To do so, we also have to change the
-    // behavior of `enter` and `escape`:
-    // Enter should automatically add the suffix to the current line as long as
-    // escape was not pressed. We might even remove the preview in case any
-    // cursor movement is triggered.
     const insertPreview = false;
     showCompletionPreview(repl.line, insertPreview);
 
@@ -397,9 +430,17 @@ function setupPreview(repl, contextSymbol, bufferSymbol, active) {
       moveCursor(repl.output, 0, -rows - 1);
     };
 
-    getInputPreview(line, inputPreviewCallback);
+    let previewLine = line;
+
+    if (completionPreview !== null &&
+        isCursorAtInputEnd() &&
+        escaped !== repl.line) {
+      previewLine += completionPreview;
+    }
+
+    getInputPreview(previewLine, inputPreviewCallback);
     if (wrapped) {
-      getInputPreview(line, inputPreviewCallback);
+      getInputPreview(previewLine, inputPreviewCallback);
     }
     wrapped = false;
   };
@@ -679,6 +720,8 @@ function setupReverseSearch(repl) {
 }
 
 module.exports = {
+  REPL_MODE_SLOPPY: Symbol('repl-sloppy'),
+  REPL_MODE_STRICT,
   isRecoverableError,
   kStandaloneREPL: Symbol('kStandaloneREPL'),
   setupPreview,