test: add tests for REPL custom evals

PR-URL: #57691
Reviewed-By: Yagiz Nizipli <yagiz@nizipli.com>
Reviewed-By: Antoine du Hamel <duhamelantoine1995@gmail.com>

Author: dario-piotrowicz

lib/repl.js

@@ -306,7 +306,6 @@ function REPLServer(prompt,
 options.useColors=shouldColorize(options.output);
 }
 
-// TODO(devsnek): Add a test case for custom eval functions.
 constpreview=options.terminal&&
 (options.preview!==undefined ? !!options.preview : !eval_);
 

test/parallel/test-repl-custom-eval.js

@@ -0,0 +1,135 @@
+'use strict';
+
+require('../common');
+constArrayStream=require('../common/arraystream');
+constassert=require('assert');
+const{ describe, it }=require('node:test');
+
+constrepl=require('repl');
+
+functiongetReplOutput(input,replOptions,run=true){
+constinputStream=newArrayStream();
+constoutputStream=newArrayStream();
+
+repl.start({
+input: inputStream,
+output: outputStream,
+ ...replOptions,
+});
+
+letoutput='';
+outputStream.write=(chunk)=>(output+=chunk);
+
+inputStream.emit('data',input);
+
+if(run){
+inputStream.run(['']);
+}
+
+returnoutput;
+}
+
+describe('repl with custom eval',{concurrency: true},()=>{
+it('uses the custom eval function as expected',()=>{
+constoutput=getReplOutput('Convert this to upper case',{
+terminal: true,
+eval: (code,_ctx,_replRes,cb)=>cb(null,code.toUpperCase()),
+});
+assert.match(
+output,
+/Convertthistouppercase\r\n'CONVERTTHISTOUPPERCASE\\n'/
+);
+});
+
+it('surfaces errors as expected',()=>{
+constoutput=getReplOutput('Convert this to upper case',{
+terminal: true,
+eval: (_code,_ctx,_replRes,cb)=>cb(newError('Testing Error')),
+});
+assert.match(output,/UncaughtError:TestingError\n/);
+});
+
+it('provides a repl context to the eval callback',async()=>{
+constcontext=awaitnewPromise((resolve)=>{
+constr=repl.start({
+eval: (_cmd,context)=>resolve(context),
+});
+r.context={foo: 'bar'};
+r.write('\n.exit\n');
+});
+assert.strictEqual(context.foo,'bar');
+});
+
+it('provides the global context to the eval callback',async()=>{
+constcontext=awaitnewPromise((resolve)=>{
+constr=repl.start({
+useGlobal: true,
+eval: (_cmd,context)=>resolve(context),
+});
+global.foo='global_foo';
+r.write('\n.exit\n');
+});
+
+assert.strictEqual(context.foo,'global_foo');
+deleteglobal.foo;
+});
+
+it('inherits variables from the global context but does not use it afterwords if `useGlobal` is false',async()=>{
+global.bar='global_bar';
+constcontext=awaitnewPromise((resolve)=>{
+constr=repl.start({
+useGlobal: false,
+eval: (_cmd,context)=>resolve(context),
+});
+global.baz='global_baz';
+r.write('\n.exit\n');
+});
+
+assert.strictEqual(context.bar,'global_bar');
+assert.notStrictEqual(context.baz,'global_baz');
+deleteglobal.bar;
+deleteglobal.baz;
+});
+
+/**
+ * Default preprocessor transforms
+ * function f() {} to
+ * var f = function f() {}
+ * This test ensures that original input is preserved.
+ * Reference: https://github.com/nodejs/node/issues/9743
+ */
+it('preserves the original input',async()=>{
+constcmd=awaitnewPromise((resolve)=>{
+constr=repl.start({
+eval: (cmd)=>resolve(cmd),
+});
+r.write('function f() {}\n.exit\n');
+});
+assert.strictEqual(cmd,'function f() {}\n');
+});
+
+it("doesn't show previews by default",()=>{
+constinput="'Hello custom' + ' eval World!'";
+constoutput=getReplOutput(input,{
+terminal: true,
+eval: (code,_ctx,_replRes,cb)=>cb(null,eval(code)),
+},false);
+assert.strictEqual(output,input);
+assert.doesNotMatch(output,/HellocustomevalWorld!/);
+});
+
+it('does show previews if `preview` is set to `true`',()=>{
+constinput="'Hello custom' + ' eval World!'";
+constoutput=getReplOutput(input,{
+terminal: true,
+eval: (code,_ctx,_replRes,cb)=>cb(null,eval(code)),
+preview: true,
+},false);
+
+constescapedInput=input.replace(/\+/g,'\\+');// TODO: migrate to `RegExp.escape` when it's available.
+assert.match(
+output,
+newRegExp(`${escapedInput}\n// 'Hello custom eval World!'`)
+);
+});
+});