repl: fix autocomplete while using .load

This makes sure that complete functions work as expected after using
the REPL's `.load` command.

It also fixes the corresponding test. So far the assertion where
swallowed and the test passed even though it should not have.

Fixes: https://github.com/nodejs/node/issues/28546
PR-URL: https://github.com/nodejs/node/pull/28608
Reviewed-By: Jiawen Geng <technicalcute@gmail.com>
Reviewed-By: Rich Trott <rtrott@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Lance Ball <lball@redhat.com>
Reviewed-By: Anto Aravinth <anto.aravinth.cse@gmail.com>

lib/repl.js

@@ -1535,10 +1535,10 @@ function defineDefaultCommands(repl) {
     help: 'Save all evaluated commands in this REPL session to a file',
     action: function(file) {
       try {
-        fs.writeFileSync(file, this.lines.join('\n') + '\n');
-        this.outputStream.write('Session saved to: ' + file + '\n');
+        fs.writeFileSync(file, this.lines.join('\n'));
+        this.outputStream.write(`Session saved to: ${file}\n`);
       } catch {
-        this.outputStream.write('Failed to save: ' + file + '\n');
+        this.outputStream.write(`Failed to save: ${file}\n`);
       }
       this.displayPrompt();
     }
@@ -1548,23 +1548,20 @@ function defineDefaultCommands(repl) {
     help: 'Load JS from a file into the REPL session',
     action: function(file) {
       try {
-        var stats = fs.statSync(file);
+        const stats = fs.statSync(file);
         if (stats && stats.isFile()) {
           _turnOnEditorMode(this);
-          var data = fs.readFileSync(file, 'utf8');
-          var lines = data.split('\n');
-          for (var n = 0; n < lines.length; n++) {
-            if (lines[n])
-              this.write(`${lines[n]}\n`);
-          }
+          const data = fs.readFileSync(file, 'utf8');
+          this.write(data);
           _turnOffEditorMode(this);
           this.write('\n');
         } else {
-          this.outputStream.write('Failed to load: ' + file +
-                                  ' is not a valid file\n');
+          this.outputStream.write(
+            `Failed to load: ${file} is not a valid file\n`
+          );
         }
       } catch {
-        this.outputStream.write('Failed to load: ' + file + '\n');
+        this.outputStream.write(`Failed to load: ${file}\n`);
       }
       this.displayPrompt();
     }

test/parallel/test-repl-load-multiline.js

@@ -13,6 +13,7 @@ const expected = `${command}
 const getLunch = () =>
   placeOrder('tacos')
     .then(eat);
+
 const placeOrder = (order) => Promise.resolve(order);
 const eat = (food) => '<nom nom nom>';
 

test/parallel/test-repl-save-load.js

@@ -20,7 +20,7 @@
 // USE OR OTHER DEALINGS IN THE SOFTWARE.
 
 'use strict';
-require('../common');
+const common = require('../common');
 const ArrayStream = require('../common/arraystream');
 const assert = require('assert');
 const join = require('path').join;
@@ -36,6 +36,12 @@ const works = [['inner.one'], 'inner.o'];
 const putIn = new ArrayStream();
 const testMe = repl.start('', putIn);
 
+// Some errors might be passed to the domain.
+testMe._domain.on('error', function(reason) {
+  const err = new Error('Test failed');
+  err.reason = reason;
+  throw err;
+});
 
 const testFile = [
   'var top = function() {',
@@ -43,18 +49,76 @@ const testFile = [
 ];
 const saveFileName = join(tmpdir.path, 'test.save.js');
 
-// input some data
+// Add some data.
 putIn.run(testFile);
 
-// save it to a file
+// Save it to a file.
 putIn.run([`.save ${saveFileName}`]);
 
-// The file should have what I wrote
+// The file should have what I wrote.
 assert.strictEqual(fs.readFileSync(saveFileName, 'utf8'),
-                   `${testFile.join('\n')}\n`);
+                   testFile.join('\n'));
+
+// Make sure that the REPL data is "correct".
+testMe.complete('inner.o', common.mustCall(function(error, data) {
+  assert.ifError(error);
+  assert.deepStrictEqual(data, works);
+}));
+
+// Clear the REPL.
+putIn.run(['.clear']);
+
+// Load the file back in.
+putIn.run([`.load ${saveFileName}`]);
+
+// Make sure that the REPL data is "correct".
+testMe.complete('inner.o', common.mustCall(function(error, data) {
+  assert.ifError(error);
+  assert.deepStrictEqual(data, works);
+}));
+
+// Clear the REPL.
+putIn.run(['.clear']);
+
+let loadFile = join(tmpdir.path, 'file.does.not.exist');
+
+// Should not break.
+putIn.write = common.mustCall(function(data) {
+  // Make sure I get a failed to load message and not some crazy error.
+  assert.strictEqual(data, `Failed to load: ${loadFile}\n`);
+  // Eat me to avoid work.
+  putIn.write = () => {};
+});
+putIn.run([`.load ${loadFile}`]);
+
+// Throw error on loading directory.
+loadFile = tmpdir.path;
+putIn.write = common.mustCall(function(data) {
+  assert.strictEqual(data, `Failed to load: ${loadFile} is not a valid file\n`);
+  putIn.write = () => {};
+});
+putIn.run([`.load ${loadFile}`]);
+
+// Clear the REPL.
+putIn.run(['.clear']);
+
+// NUL (\0) is disallowed in filenames in UNIX-like operating systems and
+// Windows so we can use that to test failed saves.
+const invalidFileName = join(tmpdir.path, '\0\0\0\0\0');
+
+// Should not break.
+putIn.write = common.mustCall(function(data) {
+  // Make sure I get a failed to save message and not some other error.
+  assert.strictEqual(data, `Failed to save: ${invalidFileName}\n`);
+  // Reset to no-op.
+  putIn.write = () => {};
+});
+
+// Save it to a file.
+putIn.run([`.save ${invalidFileName}`]);
 
 {
-  // save .editor mode code
+  // Save .editor mode code.
   const cmds = [
     'function testSave() {',
     'return "saved";',
@@ -70,62 +134,5 @@ assert.strictEqual(fs.readFileSync(saveFileName, 'utf8'),
   putIn.run([`.save ${saveFileName}`]);
   replServer.close();
   assert.strictEqual(fs.readFileSync(saveFileName, 'utf8'),
-                     `${cmds.join('\n')}\n\n`);
+                     `${cmds.join('\n')}\n`);
 }
-
-// Make sure that the REPL data is "correct"
-// so when I load it back I know I'm good
-testMe.complete('inner.o', function(error, data) {
-  assert.deepStrictEqual(data, works);
-});
-
-// clear the REPL
-putIn.run(['.clear']);
-
-// Load the file back in
-putIn.run([`.load ${saveFileName}`]);
-
-// Make sure that the REPL data is "correct"
-testMe.complete('inner.o', function(error, data) {
-  assert.deepStrictEqual(data, works);
-});
-
-// clear the REPL
-putIn.run(['.clear']);
-
-let loadFile = join(tmpdir.path, 'file.does.not.exist');
-
-// should not break
-putIn.write = function(data) {
-  // Make sure I get a failed to load message and not some crazy error
-  assert.strictEqual(data, `Failed to load:${loadFile}\n`);
-  // Eat me to avoid work
-  putIn.write = () => {};
-};
-putIn.run([`.load ${loadFile}`]);
-
-// Throw error on loading directory
-loadFile = tmpdir.path;
-putIn.write = function(data) {
-  assert.strictEqual(data, `Failed to load:${loadFile} is not a valid file\n`);
-  putIn.write = () => {};
-};
-putIn.run([`.load ${loadFile}`]);
-
-// clear the REPL
-putIn.run(['.clear']);
-
-// NUL (\0) is disallowed in filenames in UNIX-like operating systems and
-// Windows so we can use that to test failed saves
-const invalidFileName = join(tmpdir.path, '\0\0\0\0\0');
-
-// should not break
-putIn.write = function(data) {
-  // Make sure I get a failed to save message and not some other error
-  assert.strictEqual(data, `Failed to save:${invalidFileName}\n`);
-  // reset to no-op
-  putIn.write = () => {};
-};
-
-// save it to a file
-putIn.run([`.save ${invalidFileName}`]);