readline,repl: skip history entries identical to the current line

BridgeAR · MylesBorins · commit cecd25693f9c · 2020-01-16T01:39:08.000-05:00
Skip history entries that are identical to the currently visible line to improve the user experience. PR-URL: #31112 Reviewed-By: Michaël Zasso <targos@protonmail.com> Reviewed-By: James M Snell <jasnell@gmail.com>
diff --git a/lib/readline.js b/lib/readline.js
@@ -702,7 +702,8 @@ Interface.prototype._historyNext = function() {
 const search = this[kSubstringSearch] || '';
 let index = this.historyIndex - 1;
 while (index >= 0 &&
- !this.history[index].startsWith(search)) {
+ (!this.history[index].startsWith(search) ||
+ this.line === this.history[index])) {
 index--;
 }
 if (index === -1) {
@@ -721,10 +722,13 @@ Interface.prototype._historyPrev = function() {
 const search = this[kSubstringSearch] || '';
 let index = this.historyIndex + 1;
 while (index < this.history.length &&
- !this.history[index].startsWith(search)) {
+ (!this.history[index].startsWith(search) ||
+ this.line === this.history[index])) {
 index++;
 }
 if (index === this.history.length) {
+ // TODO(BridgeAR): Change this to:
+ // this.line = search;
 return;
 } else {
 this.line = this.history[index];
diff --git a/test/parallel/test-repl-history-navigation.js b/test/parallel/test-repl-history-navigation.js
@@ -138,11 +138,7 @@ const tests = [
 // UP - skipping const foo = true
 '\x1B[1G', '\x1B[0J',
 '> 555 + 909', '\x1B[12G',
- // UP - matching the identical history entry again.
- '\x1B[1G', '\x1B[0J',
- '> 555 + 909',
 // UP, UP, ENTER. UPs at the end of the history have no effect.
- '\x1B[12G',
 '\r\n',
 '1464\n',
 '\x1B[1G', '\x1B[0J',

-Original file line number
+Diff line change
 constsearch=this[kSubstringSearch]||'';
 letindex=this.historyIndex-1;
 while(index>=0&&
 -!this.history[index].startsWith(search)){
 +(!this.history[index].startsWith(search)||
 +this.line===this.history[index])){
 index--;
+}
 if(index===-1){
 constsearch=this[kSubstringSearch]||'';
 letindex=this.historyIndex+1;
 while(index<this.history.length&&
 -!this.history[index].startsWith(search)){
 +(!this.history[index].startsWith(search)||
 +this.line===this.history[index])){
 index++;
+}
 if(index===this.history.length){
 +// TODO(BridgeAR): Change this to:
 +// this.line = search;
 return;
 }else{
 this.line=this.history[index];