fs: readline

Fix: #12606

Author: Tseian

lib/internal/readline/interface.js

@@ -125,13 +125,15 @@ const kOnLine = Symbol('_onLine');
 const kSetLine = Symbol('_setLine');
 const kPreviousKey = Symbol('_previousKey');
 const kPrompt = Symbol('_prompt');
+const kPromptInvoked = Symbol('_promptInvoked');
 const kPushToKillRing = Symbol('_pushToKillRing');
 const kPushToUndoStack = Symbol('_pushToUndoStack');
 const kQuestionCallback = Symbol('_questionCallback');
 const kLastCommandErrored = Symbol('_lastCommandErrored');
 const kQuestionReject = Symbol('_questionReject');
 const kRedo = Symbol('_redo');
 const kRedoStack = Symbol('_redoStack');
+const kEffectivePrompt = Symbol('_effectivePrompt');
 const kRefreshLine = Symbol('_refreshLine');
 const kSawKeyPress = Symbol('_sawKeyPress');
 const kSawReturnAt = Symbol('_sawReturnAt');
@@ -252,6 +254,7 @@ function InterfaceConstructor(input, output, completer, terminal) {
   this.completer = completer;
 
   this.setPrompt(prompt);
+  this[kPromptInvoked] = false;
 
   this.terminal = !!terminal;
 
@@ -428,6 +431,7 @@ class Interface extends InterfaceConstructor {
    */
   prompt(preserveCursor) {
     if (this.paused) this.resume();
+    this[kPromptInvoked] = true;
     if (this.terminal && process.env.TERM !== 'dumb') {
       if (!preserveCursor) this.cursor = 0;
       this[kRefreshLine]();
@@ -490,9 +494,14 @@ class Interface extends InterfaceConstructor {
     return this.historyManager.addHistory(this[kIsMultiline], this[kLastCommandErrored]);
   }
 
+  [kEffectivePrompt]() {
+    return this[kPromptInvoked] ? this[kPrompt] : '';
+  }
+
   [kRefreshLine]() {
     // line length
-    const line = this[kPrompt] + this.line;
+    const promptPrefix = this[kEffectivePrompt]();
+    const line = promptPrefix + this.line;
     const dispPos = this[kGetDisplayPos](line);
     const lineCols = dispPos.cols;
     const lineRows = dispPos.rows;
@@ -514,7 +523,7 @@ class Interface extends InterfaceConstructor {
     if (this[kIsMultiline]) {
       const lines = StringPrototypeSplit(this.line, '\n');
       // Write first line with normal prompt
-      this[kWriteToOutput](this[kPrompt] + lines[0]);
+      this[kWriteToOutput](promptPrefix + lines[0]);
 
       // For continuation lines, add the "|" prefix
       for (let i = 1; i < lines.length; i++) {
@@ -1020,7 +1029,9 @@ class Interface extends InterfaceConstructor {
     }
 
     if (needsRewriteFirstLine) {
-      this[kWriteToOutput](`${this[kPrompt]}${beforeCursor}\n${kMultilinePrompt.description}`);
+      this[kWriteToOutput](
+        `${this[kEffectivePrompt]()}${beforeCursor}\n${kMultilinePrompt.description}`,
+      );
     } else {
       this[kWriteToOutput](kMultilinePrompt.description);
     }
@@ -1221,7 +1232,8 @@ class Interface extends InterfaceConstructor {
    *   }}
    */
   getCursorPos() {
-    const strBeforeCursor = this[kPrompt] + StringPrototypeSlice(this.line, 0, this.cursor);
+    const strBeforeCursor = this[kEffectivePrompt]() +
+      StringPrototypeSlice(this.line, 0, this.cursor);
 
     return this[kGetDisplayPos](strBeforeCursor);
   }