test: refactor repl save-load tests

refactor the test/parallel/test-repl-save-load.js file by:
  - making the tests in the file self-contained
    (instead of all of them sharing the same REPL instance and
     constantly calling `.clear` on it)
  - clearly separating and commenting the various tests to make
    clearer what is being tested

PR-URL: #58715
Reviewed-By: Luigi Pinca <[email protected]>

Author: dario-piotrowicz

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

@@ -0,0 +1,48 @@
+'use strict';
+
+require('../common');
+const ArrayStream = require('../common/arraystream');
+
+const assert = require('node:assert');
+const fs = require('node:fs');
+const repl = require('node:repl');
+const path = require('node:path');
+
+const tmpdir = require('../common/tmpdir');
+tmpdir.refresh();
+
+// Test for saving a REPL session in editor mode
+
+const input = new ArrayStream();
+
+const replServer = repl.start({
+  prompt: '',
+  input,
+  output: new ArrayStream(),
+  allowBlockingCompletions: true,
+  terminal: true,
+});
+
+// Some errors are passed to the domain, but do not callback
+replServer._domain.on('error', assert.ifError);
+
+input.run(['.editor']);
+
+const commands = [
+  'function testSave() {',
+  'return "saved";',
+  '}',
+];
+
+input.run(commands);
+
+replServer.write('', { ctrl: true, name: 'd' });
+
+const filePath = path.resolve(tmpdir.path, 'test.save.js');
+
+input.run([`.save ${filePath}`]);
+
+assert.strictEqual(fs.readFileSync(filePath, 'utf8'),
+                   `${commands.join('\n')}\n`);
+
+replServer.close();

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

@@ -0,0 +1,38 @@
+'use strict';
+
+const common = require('../common');
+const ArrayStream = require('../common/arraystream');
+
+const assert = require('node:assert');
+const repl = require('node:repl');
+
+const tmpdir = require('../common/tmpdir');
+tmpdir.refresh();
+
+// Test for the appropriate handling of cases in which REPL saves fail
+
+const input = new ArrayStream();
+const output = new ArrayStream();
+
+const replServer = repl.start({
+  prompt: '',
+  input,
+  output,
+  allowBlockingCompletions: true,
+});
+
+// Some errors are passed to the domain, but do not callback
+replServer._domain.on('error', assert.ifError);
+
+// NUL (\0) is disallowed in filenames in UNIX-like operating systems and
+// Windows so we can use that to test failed saves.
+const invalidFilePath = tmpdir.resolve('\0\0\0\0\0');
+
+output.write = common.mustCall(function(data) {
+  assert.strictEqual(data, `Failed to save: ${invalidFilePath}\n`);
+  output.write = () => {};
+});
+
+input.run([`.save ${invalidFilePath}`]);
+
+replServer.close();

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

@@ -0,0 +1,36 @@
+'use strict';
+
+const common = require('../common');
+const ArrayStream = require('../common/arraystream');
+
+const assert = require('node:assert');
+const repl = require('node:repl');
+
+const tmpdir = require('../common/tmpdir');
+tmpdir.refresh();
+
+// Tests that an appropriate error is displayed if the user tries to load a directory instead of a file
+
+const input = new ArrayStream();
+const output = new ArrayStream();
+
+const replServer = repl.start({
+  prompt: '',
+  input,
+  output,
+  allowBlockingCompletions: true,
+});
+
+// Some errors are passed to the domain, but do not callback
+replServer._domain.on('error', assert.ifError);
+
+const dirPath = tmpdir.path;
+
+output.write = common.mustCall(function(data) {
+  assert.strictEqual(data, `Failed to load: ${dirPath} is not a valid file\n`);
+  output.write = () => {};
+});
+
+input.run([`.load ${dirPath}`]);
+
+replServer.close();

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

@@ -0,0 +1,36 @@
+'use strict';
+
+const common = require('../common');
+const ArrayStream = require('../common/arraystream');
+
+const assert = require('node:assert');
+const repl = require('node:repl');
+
+const tmpdir = require('../common/tmpdir');
+tmpdir.refresh();
+
+// Tests that an appropriate error is displayed if the user tries to load a non existent file
+
+const input = new ArrayStream();
+const output = new ArrayStream();
+
+const replServer = repl.start({
+  prompt: '',
+  input,
+  output,
+  allowBlockingCompletions: true,
+});
+
+// Some errors are passed to the domain, but do not callback
+replServer._domain.on('error', assert.ifError);
+
+const filePath = tmpdir.resolve('file.does.not.exist');
+
+output.write = common.mustCall(function(data) {
+  assert.strictEqual(data, `Failed to load: ${filePath}\n`);
+  output.write = () => {};
+});
+
+input.run([`.load ${filePath}`]);
+
+replServer.close();

test/parallel/test-repl-save-load-load-without-name.js

@@ -0,0 +1,34 @@
+'use strict';
+
+const common = require('../common');
+const ArrayStream = require('../common/arraystream');
+
+const assert = require('node:assert');
+const repl = require('node:repl');
+
+const tmpdir = require('../common/tmpdir');
+tmpdir.refresh();
+
+// Tests that an appropriate error is displayed if .load is called without a filename
+
+const input = new ArrayStream();
+const output = new ArrayStream();
+
+const replServer = repl.start({
+  prompt: '',
+  input,
+  output,
+  allowBlockingCompletions: true,
+});
+
+// Some errors are passed to the domain, but do not callback
+replServer._domain.on('error', assert.ifError);
+
+output.write = common.mustCall(function(data) {
+  assert.strictEqual(data, 'The "file" argument must be specified\n');
+  output.write = () => {};
+});
+
+input.run(['.load']);
+
+replServer.close();

test/parallel/test-repl-save-load-save-without-name.js

@@ -0,0 +1,34 @@
+'use strict';
+
+const common = require('../common');
+const ArrayStream = require('../common/arraystream');
+
+const assert = require('node:assert');
+const repl = require('node:repl');
+
+const tmpdir = require('../common/tmpdir');
+tmpdir.refresh();
+
+// Tests that an appropriate error is displayed if .save is called without a filename
+
+const input = new ArrayStream();
+const output = new ArrayStream();
+
+const replServer = repl.start({
+  prompt: '',
+  input,
+  output,
+  allowBlockingCompletions: true,
+});
+
+// Some errors are passed to the domain, but do not callback
+replServer._domain.on('error', assert.ifError);
+
+output.write = common.mustCall(function(data) {
+  assert.strictEqual(data, 'The "file" argument must be specified\n');
+  output.write = () => {};
+});
+
+input.run(['.save']);
+
+replServer.close();