readline: add autoCommit option

aduh95 · aduh95 · commit 341312d78a8b · 2021-09-16T23:16:46.000+02:00
PR-URL: #37947 Fixes: #37287 Reviewed-By: Matteo Collina <matteo.collina@gmail.com> Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com> Reviewed-By: Robert Nagy <ronagy@icloud.com>
diff --git a/doc/api/readline.md b/doc/api/readline.md
@@ -599,12 +599,14 @@ setTimeout(() => ac.abort(), 10000);
 added: REPLACEME
 -->
 
-#### `new readlinePromises.Readline(stream)`
+#### `new readlinePromises.Readline(stream[, options])`
 <!-- YAML
 added: REPLACEME
 -->
 
 * `stream` {stream.Writable} A [TTY][] stream.
+* `options` {Object}
+  * `autoCommit` {boolean} If `true`, no need to call `rl.commit()`.
 
 #### `rl.clearLine(dir)`
 <!-- YAML
@@ -620,7 +622,8 @@ added: REPLACEME
 The `rl.clearLine()` method adds to the internal list of pending action an
 action that clears current line of the associated `stream` in a specified
 direction identified by `dir`.
-You need to call `rl.commit()` to see the effect of this method.
+Call `rl.commit()` to see the effect of this method, unless `autoCommit: true`
+was passed to the constructor.
 
 #### `rl.clearScreenDown()`
 <!-- YAML
@@ -632,7 +635,8 @@ added: REPLACEME
 The `rl.clearScreenDown()` method adds to the internal list of pending action an
 action that clears the associated stream from the current position of the
 cursor down.
-You need to call `rl.commit()` to see the effect of this method.
+Call `rl.commit()` to see the effect of this method, unless `autoCommit: true`
+was passed to the constructor.
 
 #### `rl.commit()`
 <!-- YAML
@@ -655,7 +659,8 @@ added: REPLACEME
 
 The `rl.cursorTo()` method adds to the internal list of pending action an action
 that moves cursor to the specified position in the associated `stream`.
-You need to call `rl.commit()` to see the effect of this method.
+Call `rl.commit()` to see the effect of this method, unless `autoCommit: true`
+was passed to the constructor.
 
 #### `rl.moveCursor(dx, dy)`
 <!-- YAML
@@ -669,7 +674,8 @@ added: REPLACEME
 The `rl.moveCursor()` method adds to the internal list of pending action an
 action that moves the cursor *relative* to its current position in the
 associated `stream`.
-You need to call `rl.commit()` to see the effect of this method.
+Call `rl.commit()` to see the effect of this method, unless `autoCommit: true`
+was passed to the constructor.
 
 #### `rl.rollback()`
 <!-- YAML
diff --git a/lib/internal/readline/promises.js b/lib/internal/readline/promises.js
@@ -7,7 +7,7 @@ const {
 } = primordials;
 
 const { CSI } = require('internal/readline/utils');
-const { validateInteger } = require('internal/validators');
+const { validateBoolean, validateInteger } = require('internal/validators');
 const { isWritable } = require('internal/streams/utils');
 const { codes: { ERR_INVALID_ARG_TYPE } } = require('internal/errors');
 
@@ -19,13 +19,18 @@ const {
 } = CSI;
 
 class Readline {
+  #autoCommit = false;
   #stream;
   #todo = [];
 
-  constructor(stream) {
+  constructor(stream, options = undefined) {
     if (!isWritable(stream))
       throw new ERR_INVALID_ARG_TYPE('stream', 'Writable', stream);
     this.#stream = stream;
+    if (options?.autoCommit != null) {
+      validateBoolean(options.autoCommit, 'options.autoCommit');
+      this.#autoCommit = options.autoCommit;
+    }
   }
 
   /**
@@ -38,10 +43,9 @@ class Readline {
     validateInteger(x, 'x');
     if (y != null) validateInteger(y, 'y');
 
-    ArrayPrototypePush(
-      this.#todo,
-      y == null ? CSI`${x + 1}G` : CSI`${y + 1};${x + 1}H`
-    );
+    const data = y == null ? CSI`${x + 1}G` : CSI`${y + 1};${x + 1}H`;
+    if (this.#autoCommit) process.nextTick(() => this.#stream.write(data));
+    else ArrayPrototypePush(this.#todo, data);
 
     return this;
   }
@@ -70,7 +74,8 @@ class Readline {
       } else if (dy > 0) {
         data += CSI`${dy}B`;
       }
-      ArrayPrototypePush(this.#todo, data);
+      if (this.#autoCommit) process.nextTick(() => this.#stream.write(data));
+      else ArrayPrototypePush(this.#todo, data);
     }
     return this;
   }
@@ -86,10 +91,12 @@ class Readline {
   clearLine(dir) {
     validateInteger(dir, 'dir', -1, 1);
 
-    ArrayPrototypePush(
-      this.#todo,
-      dir < 0 ? kClearToLineBeginning : dir > 0 ? kClearToLineEnd : kClearLine
-    );
+    const data =
+      dir < 0 ? kClearToLineBeginning :
+        dir > 0 ? kClearToLineEnd :
+          kClearLine;
+    if (this.#autoCommit) process.nextTick(() => this.#stream.write(data));
+    else ArrayPrototypePush(this.#todo, data);
     return this;
   }
 
@@ -98,7 +105,11 @@ class Readline {
    * @returns {Readline} this
    */
   clearScreenDown() {
-    ArrayPrototypePush(this.#todo, kClearScreenDown);
+    if (this.#autoCommit) {
+      process.nextTick(() => this.#stream.write(kClearScreenDown));
+    } else {
+      ArrayPrototypePush(this.#todo, kClearScreenDown);
+    }
     return this;
   }
 
