repl: add support for multiline history

lib/internal/readline/interface.js

@@ -24,8 +24,11 @@ const {
   SafeStringIterator,
   StringPrototypeCodePointAt,
   StringPrototypeEndsWith,
+  StringPrototypeIndexOf,
   StringPrototypeRepeat,
+  StringPrototypeReplaceAll,
   StringPrototypeSlice,
+  StringPrototypeSplit,
   StringPrototypeStartsWith,
   StringPrototypeTrim,
   Symbol,
@@ -99,7 +102,9 @@ const kDeleteWordLeft = Symbol('_deleteWordLeft');
 const kDeleteWordRight = Symbol('_deleteWordRight');
 const kGetDisplayPos = Symbol('_getDisplayPos');
 const kHistoryNext = Symbol('_historyNext');
+const kMoveDownOrHistoryNext = Symbol('_moveDownOrHistoryNext');
 const kHistoryPrev = Symbol('_historyPrev');
+const kMoveUpOrHistoryPrev = Symbol('_moveUpOrHistoryPrev');
 const kInsertString = Symbol('_insertString');
 const kLine = Symbol('_line');
 const kLine_buffer = Symbol('_line_buffer');
@@ -449,8 +454,15 @@ class Interface extends InterfaceConstructor {
 
     // If the trimmed line is empty then return the line
     if (StringPrototypeTrim(this.line).length === 0) return this.line;
-
-    if (this.history.length === 0 || this.history[0] !== this.line) {
+    const normalizedLine = StringPrototypeReplaceAll(this.line, '\n', '\r');
+
+    if (this.history.length === 0 || this.history[0] !== normalizedLine) {
+      if (this.lastCommandErrored && this.historyIndex === 0) {
+        // If the last command errored, remove it from history.
+        // The user is issuing a new command starting from the errored command,
+        // Hopefully with the fix
+        ArrayPrototypeShift(this.history);
+      }
       if (this.removeHistoryDuplicates) {
         // Remove older history line if identical to new one
         const dupIndex = ArrayPrototypeIndexOf(this.history, this.line);
@@ -498,8 +510,22 @@ class Interface extends InterfaceConstructor {
     // erase data
     clearScreenDown(this.output);
 
-    // Write the prompt and the current buffer content.
-    this[kWriteToOutput](line);
+    // Check if this is a multiline entry
+    const lines = StringPrototypeSplit(this.line, '\n');
+    const isMultiline = lines.length > 1;
+
+    if (!isMultiline) {
+      // Write the prompt and the current buffer content.
+      this[kWriteToOutput](line);
+    } else {
+      // Write first line with normal prompt
+      this[kWriteToOutput](this[kPrompt] + lines[0]);
+
+      // For continuation lines, add the "|" prefix
+      for (let i = 1; i < lines.length; i++) {
+        this[kWriteToOutput]('\n| ' + lines[i]);
+      }
+    }
 
     // Force terminal to allocate a new line
     if (lineCols === 0) {
@@ -928,6 +954,29 @@ class Interface extends InterfaceConstructor {
     this[kRefreshLine]();
   }
 
+  [kMoveDownOrHistoryNext]() {
+    const { cols, rows } = this.getCursorPos();
+    const splitLine = StringPrototypeSplit(this.line, '\n');
+    if (!this.historyIndex && rows === splitLine.length) {
+      return;
+    }
+    // Go to the next history only if the cursor is in the first line of the multiline input.
+    // Otherwise treat the "arrow down" as a movement to the next row.
+    if (splitLine.length > 1 && rows < splitLine.length - 1) {
+      const currentLine = splitLine[rows];
+      const nextLine = splitLine[rows + 1];
+      const amountToMove = (cols > nextLine.length + 1) ?
+        currentLine.length - cols + nextLine.length + 3 :
+        currentLine.length + 1;
+      // Go to the same position on the next line, or the end of the next line
+      // If the current position does not exist in the next line.
+      this[kMoveCursor](amountToMove);
+      return;
+    }
+
+    this[kHistoryNext]();
+  }
+
   // TODO(BridgeAR): Add underscores to the search part and a red background in
   // case no match is found. This should only be the visual part and not the
   // actual line content!
@@ -950,14 +999,36 @@ class Interface extends InterfaceConstructor {
       if (index === -1) {
         this.line = search;
       } else {
-        this.line = this.history[index];
+        this.line = StringPrototypeReplaceAll(this.history[index], '\r', '\n');
       }
       this.historyIndex = index;
       this.cursor = this.line.length; // Set cursor to end of line.
       this[kRefreshLine]();
     }
   }
 
+  [kMoveUpOrHistoryPrev]() {
+    const { cols, rows } = this.getCursorPos();
+    if (this.historyIndex === this.history.length && rows) {
+      return;
+    }
+    const splitLine = StringPrototypeSplit(this.line, '\n');
+    // Go to the previous history only if the cursor is in the first line of the multiline input.
+    // Otherwise treat the "arrow up" as a movement to the previous row.
+    if (splitLine.length > 1 && rows > 0) {
+      const previousLine = splitLine[rows - 1];
+      const amountToMove = (cols > previousLine.length + 1) ?
+        -cols + 1 :
+        -previousLine.length - 1;
+      // Go to the same position on the previous line, or the end of the previous line
+      // If the current position does not exist in the previous line.
+      this[kMoveCursor](amountToMove);
+      return;
+    }
+
+    this[kHistoryPrev]();
+  }
+
   [kHistoryPrev]() {
     if (this.historyIndex < this.history.length && this.history.length) {
       this[kBeforeEdit](this.line, this.cursor);
@@ -973,7 +1044,7 @@ class Interface extends InterfaceConstructor {
       if (index === this.history.length) {
         this.line = search;
       } else {
-        this.line = this.history[index];
+        this.line = StringPrototypeReplaceAll(this.history[index], '\r', '\n');
       }
       this.historyIndex = index;
       this.cursor = this.line.length; // Set cursor to end of line.
@@ -1024,9 +1095,19 @@ class Interface extends InterfaceConstructor {
    *   }}
    */
   getCursorPos() {
-    const strBeforeCursor =
-      this[kPrompt] + StringPrototypeSlice(this.line, 0, this.cursor);
-    return this[kGetDisplayPos](strBeforeCursor);
+    // Handle multiline input by accounting for "| " prefixes on continuation lines
+    const lineUptoCursor = StringPrototypeSlice(this.line, 0, this.cursor);
+    const lines = StringPrototypeSplit(lineUptoCursor, '\n');
+
+    // First line uses normal prompt, subsequent lines use "| " (2 chars)
+    let displayText = this[kPrompt] + lines[0];
+
+    // Add continuation lines with their prefixes
+    for (let i = 1; i < lines.length; i++) {
+      displayText += '\n| ' + lines[i];
+    }
+
+    return this[kGetDisplayPos](displayText);
   }
 
   // This function moves cursor dx places to the right
@@ -1074,7 +1155,8 @@ class Interface extends InterfaceConstructor {
       !key.meta &&
       !key.shift
     ) {
-      if (this[kSubstringSearch] === null) {
+      const isLineMultiline = StringPrototypeIndexOf(this.line, '\n') !== -1;
+      if (this[kSubstringSearch] === null && !isLineMultiline) {
         this[kSubstringSearch] = StringPrototypeSlice(
           this.line,
           0,
@@ -1308,11 +1390,11 @@ class Interface extends InterfaceConstructor {
           break;
 
         case 'up':
-          this[kHistoryPrev]();
+          this[kMoveUpOrHistoryPrev]();
           break;
 
         case 'down':
-          this[kHistoryNext]();
+          this[kMoveDownOrHistoryNext]();
           break;
 
         case 'tab':

lib/internal/repl/history.js

@@ -97,7 +97,7 @@ function setupHistory(repl, historyPath, ready) {
     }
 
     if (data) {
-      repl.history = RegExpPrototypeSymbolSplit(/[\n\r]+/, data, repl.historySize);
+      repl.history = RegExpPrototypeSymbolSplit(/[\n]+/, data, repl.historySize);
     } else {
       repl.history = [];
     }

lib/internal/repl/utils.js

@@ -155,8 +155,15 @@ function setupPreview(repl, contextSymbol, bufferSymbol, active) {
 
   let escaped = null;
 
+  let justExecutedMultilineCommand = false;
+
   function getPreviewPos() {
     const displayPos = repl._getDisplayPos(`${repl.getPrompt()}${repl.line}`);
+    // If the line is a multi line
+    if (StringPrototypeIndexOf(repl.line, '\n') !== -1) {
+      // This is to consider the additional "| " that prefixes the line
+      displayPos.cols += 2;
+    }
     const cursorPos = repl.line.length !== repl.cursor ?
       repl.getCursorPos() :
       displayPos;
@@ -177,6 +184,11 @@ function setupPreview(repl, contextSymbol, bufferSymbol, active) {
       clearLine(repl.output);
       moveCursor(repl.output, 0, -rows);
       inputPreview = null;
+      // If pressing enter on some history line,
+      // The next preview should not be generated
+      if ((key.name === 'return' || key.name === 'enter') && !key.meta && repl.historyIndex !== -1) {
+        justExecutedMultilineCommand = true;
+      }
     }
     if (completionPreview !== null) {
       // Prevent cursor moves if not necessary!
@@ -373,6 +385,11 @@ function setupPreview(repl, contextSymbol, bufferSymbol, active) {
       return;
     }
 
+    if (justExecutedMultilineCommand) {
+      justExecutedMultilineCommand = false;
+      return;
+    }
+
     hasCompletions = false;
 
     // Add the autocompletion preview.
@@ -444,9 +461,14 @@ function setupPreview(repl, contextSymbol, bufferSymbol, active) {
 
       const { cursorPos, displayPos } = getPreviewPos();
       const rows = displayPos.rows - cursorPos.rows;
+      // Moves one line below all the user lines
       moveCursor(repl.output, 0, rows);
+      // Writes the preview there
       repl.output.write(`\n${result}`);
+
+      // Go back to the horizontal position of the cursor
       cursorTo(repl.output, cursorPos.cols);
+      // Go back to the vertical position of the cursor
       moveCursor(repl.output, 0, -rows - 1);
     };
 

lib/repl.js

@@ -83,7 +83,9 @@ const {
   StringPrototypeCodePointAt,
   StringPrototypeEndsWith,
   StringPrototypeIncludes,
+  StringPrototypeIndexOf,
   StringPrototypeRepeat,
+  StringPrototypeReplaceAll,
   StringPrototypeSlice,
   StringPrototypeSplit,
   StringPrototypeStartsWith,
@@ -949,7 +951,32 @@ function REPLServer(prompt,
           self.displayPrompt();
           return;
         }
+      }
+
+      // In the next two if blocks, we do not use os.EOL instead of '\n'
+      // because on Windows it is '\r\n'
+      if (cmd && StringPrototypeIndexOf(cmd, '\n') !== -1) { // If you are editing a multiline command
+        self.history[0] = StringPrototypeReplaceAll(cmd, '\n', '\r');
+      } else if (self[kBufferedCommandSymbol]) { // If a new multiline command was entered
+        // Remove the first N lines from the self.history array
+        // where N is the number of lines in the buffered command
+
+        const lines = StringPrototypeSplit(self[kBufferedCommandSymbol], '\n');
+        self.history = ArrayPrototypeSlice(self.history, lines.length);
+        ArrayPrototypePop(lines);
+        // And replace them with the single command split by '\r'
+        ArrayPrototypePush(lines, cmd);
+        const newHistoryLine = ArrayPrototypeJoin(lines, '\r');
+        if (self.history[0] !== newHistoryLine) {
+          ArrayPrototypeUnshift(self.history, newHistoryLine);
+        }
+      }
+
+      if (e) {
         self._domain.emit('error', e.err || e);
+        self.lastCommandErrored = true;
+      } else {
+        self.lastCommandErrored = false;
       }
 
       // Clear buffer if no SyntaxErrors
@@ -1189,7 +1216,7 @@ REPLServer.prototype.resetContext = function() {
 REPLServer.prototype.displayPrompt = function(preserveCursor) {
   let prompt = this._initialPrompt;
   if (this[kBufferedCommandSymbol].length) {
-    prompt = '...';
+    prompt = '|';
     const len = this.lines.level.length ? this.lines.level.length - 1 : 0;
     const levelInd = StringPrototypeRepeat('..', len);
     prompt += levelInd + ' ';

test/fixtures/.node_repl_history-multiline

@@ -0,0 +1,4 @@
+var d = [  {    a: 1,    b: 2,  },  {    a: 3,    b: 4,    c: [{ a: 1, b: 2 },      {        a: 3,        b: 4,      }    ]  }]
+const c = [  {    a: 1,    b: 2,  }]
+`const b = [  1,  2,  3,  4,]`
+a = `I am a multiline stringI can be as long as I want`