readline: allow passing prompt to constructor

Previously, one would have to call setPrompt after calling rl.createInterface. Now, the prompt string can be set by passing the prompt property. PR-URL: #7125 Reviewed-By: Colin Ihrig <[email protected]> Reviewed-By: James M Snell <[email protected]> Reviewed-By: Jeremiah Senkpiel <[email protected]>

Author: evanlucas

doc/api/readline.md

@@ -357,6 +357,7 @@ added: v0.1.98
  the history set this value to `0`. Defaults to `30`. This option makes sense
  only if `terminal` is set to `true` by the user or by an internal `output`
  check, otherwise the history caching mechanism is not initialized at all.
+*`prompt` - the prompt string to use. Default: `'> '`
 
 The `readline.createInterface()` method creates a new `readline.Interface`
 instance.
@@ -467,9 +468,12 @@ implement a small command-line interface:
 
 ```js
 constreadline=require('readline');
-constrl=readline.createInterface(process.stdin, process.stdout);
+constrl=readline.createInterface({
+ input:process.stdin,
+ output:process.stdout,
+ prompt:'OHAI> '
+});
 
-rl.setPrompt('OHAI> ');
 rl.prompt();
 
 rl.on('line', (line) =>{

lib/readline.js

@@ -45,13 +45,17 @@ function Interface(input, output, completer, terminal){
 
 EventEmitter.call(this);
 varhistorySize;
+letprompt='> ';
 
 if(arguments.length===1){
 // an options object was given
 output=input.output;
 completer=input.completer;
 terminal=input.terminal;
 historySize=input.historySize;
+if(input.prompt!==undefined){
+prompt=input.prompt;
+}
 input=input.input;
 }
 
@@ -88,7 +92,7 @@ function Interface(input, output, completer, terminal){
 };
 }
 
-this.setPrompt('> ');
+this.setPrompt(prompt);
 
 this.terminal=!!terminal;
 

lib/repl.js

@@ -385,11 +385,10 @@ function REPLServer(prompt,
 output: self.outputStream,
 completer: complete,
 terminal: options.terminal,
-historySize: options.historySize
+historySize: options.historySize,
+ prompt
 });
 
-self.setPrompt(prompt!==undefined ? prompt : '> ');
-
 this.commands=Object.create(null);
 defineDefaultCommands(this);
 
@@ -408,8 +407,6 @@ function REPLServer(prompt,
 };
 }
 
-self.setPrompt(self._prompt);
-
 self.on('close',function(){
 self.emit('exit');
 });

test/parallel/test-readline-interface.js

@@ -1,9 +1,12 @@
 'use strict';
-require('../common');
-varassert=require('assert');
-varreadline=require('readline');
-varEventEmitter=require('events').EventEmitter;
-varinherits=require('util').inherits;
+constcommon=require('../common');
+constassert=require('assert');
+constreadline=require('readline');
+constinternalReadline=require('internal/readline');
+constEventEmitter=require('events').EventEmitter;
+constinherits=require('util').inherits;
+constWritable=require('stream').Writable;
+constReadable=require('stream').Readable;
 
 functionFakeInput(){
 EventEmitter.call(this);
@@ -400,4 +403,29 @@ function isWarned(emitter){
 });
 });
 
+{
+constexpected=terminal
+ ? ['\u001b[1G','\u001b[0J','$ ','\u001b[3G']
+ : ['$ '];
+
+letcounter=0;
+constoutput=newWritable({
+write: common.mustCall((chunk,enc,cb)=>{
+assert.strictEqual(chunk.toString(),expected[counter++]);
+cb();
+rl.close();
+},expected.length)
+});
+
+constrl=readline.createInterface({
+input: newReadable({read: ()=>{}}),
+output: output,
+prompt: '$ ',
+terminal: terminal
+});
+
+rl.prompt();
+
+assert.strictEqual(rl._prompt,'$ ');
+}
 });