repl: fix pasting after moving the cursor to the left

Fixes: #60446 PR-URL: #60470 Reviewed-By: Jordan Harband <[email protected]>

Author: BridgeAR

lib/internal/readline/interface.js

@@ -659,7 +659,17 @@ class Interface extends InterfaceConstructor{
 [kInsertString](c){
 this[kBeforeEdit](this.line,this.cursor);
 if(!this.isCompletionEnabled){
-this.line+=c;
+if(this.cursor<this.line.length){
+constbeg=StringPrototypeSlice(this.line,0,this.cursor);
+constend=StringPrototypeSlice(
+this.line,
+this.cursor,
+this.line.length,
+);
+this.line=beg+c+end;
+}else{
+this.line+=c;
+}
 this.cursor+=c.length;
 this[kWriteToOutput](c);
 return;

test/parallel/test-repl-paste-big-data.js

@@ -9,6 +9,11 @@ const{startNewREPLServer } = require('../common/repl');
 constcpuUsage=process.cpuUsage();
 
 const{ replServer }=startNewREPLServer({},{disableDomainErrorAssert: true});
+replServer.input.emit('data','{}');
+replServer.input.emit('keypress','',{name: 'left'});
+replServer.input.emit('data','node');
+assert.strictEqual(replServer.line,'{node}');
+
 replServer.input.emit('data','a'.repeat(2e4)+'\n');
 replServer.input.emit('data','.exit\n');