replServer defineCommand

[safarishi]

• Version: v4.4.5
• Platform: Linux lts 4.4.0-24-generic The binary and long term compatibility with node #43-Ubuntu SMP Wed Jun 8 19:27:37 UTC 2016 x86_64 x86_64 x86_64 GNU/Linux
• Subsystem:

When I try this demo

// repl_test.js
const repl = require('repl');

var replServer = repl.start({});
replServer.defineCommand('sayhello', {
  help: 'Say hello',
  action: function(name) {
    this.write(`Hello, ${name}!\n`);
    this.displayPrompt();
  }
});

then run this in my command line with node repl_test.js
// and got the output with

.sayhello Node.js User
Hello, Node.js User!
SyntaxError: Unexpected identifier
at Object.exports.createScript (vm.js:24:10)
at REPLServer.defaultEval (repl.js:235:25)
at bound (domain.js:287:14)
at REPLServer.runBound as eval
at REPLServer. (repl.js:431:12)
at emitOne (events.js:77:13)
at REPLServer.emit (events.js:169:7)
at REPLServer.Interface._onLine (readline.js:211:10)
at REPLServer.Interface._line (readline.js:550:8)
at REPLServer.Interface._ttyWrite (readline.js:885:20)

It got the synatax error, and I don't know why?

[mscdex]

The example in the docs looks incorrect/bad. I think it should be something like console.log() instead of this.write() inside the action function. Otherwise two things happen:

1. Node tries to interpret the argument passed to this.write() as code (or command if starting with .) to execute.
2. Node inserts the same argument into the REPL history, which is annoying and would almost always be undesired.

[safarishi]

Thank you for your answer,I retried this with replace the code
this.write(Hello, ${name}!\n);
to console.log(name);
and it worked all right.
thankyou