repl: refactor repl.js

There is some unnecessary logic in repl.js. Remove it.
PR-URL: #6071
Reviewed-By: James M Snell <jasnell@gmail.com>

Author: Trott

lib/repl.js

@@ -396,7 +396,6 @@ function REPLServer(prompt,
 self.on('line',function(cmd){
 debug('line %j',cmd);
 sawSIGINT=false;
-varskipCatchall=false;
 
 // leading whitespaces in template literals should not be trimmed.
 if(self._inTemplateLiteral){
@@ -415,11 +414,12 @@ function REPLServer(prompt,
 return;
 }elseif(!self.bufferedCommand){
 self.outputStream.write('Invalid REPL keyword\n');
-skipCatchall=true;
+finish(null);
+return;
 }
 }
 
-if(!skipCatchall&&(cmd||(!cmd&&self.bufferedCommand))){
+if(cmd||self.bufferedCommand){
 varevalCmd=self.bufferedCommand+cmd;
 if(/^\s*\{/.test(evalCmd)&&/\}\s*$/.test(evalCmd)){
 // It's confusing for `{ a : 1 }` to be interpreted as a block
@@ -1002,7 +1002,7 @@ REPLServer.prototype.memory = function memory(cmd) {
 // self.lines.level.length === 0
 // TODO? keep a log of level so that any syntax breaking lines can
 // be cleared on .break and in the case of a syntax error?
-// TODO? if a log was kept, then I could clear the bufferedComand and
+// TODO? if a log was kept, then I could clear the bufferedCommand and
 // eval these lines and throw the syntax error
 }else{
 self.lines.level=[];

test/parallel/test-repl-null.js

@@ -0,0 +1,17 @@
+'use strict';
+require('../common');
+constrepl=require('repl');
+constassert=require('assert');
+
+varreplserver=newrepl.REPLServer();
+
+replserver._inTemplateLiteral=true;
+
+// `null` gets treated like an empty string. (Should it? You have to do some
+// strange business to get it into the REPL. Maybe it should really throw?)
+
+assert.doesNotThrow(()=>{
+replserver.emit('line',null);
+});
+
+replserver.emit('line','.exit');