lib: add escapeCodeTimeout as an option to createInterface

PR-URL: #19780
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>
Signed-off-by: Beth Griggs <Bethany.Griggs@uk.ibm.com>

doc/api/readline.md

@@ -375,6 +375,11 @@ changes:
   * `removeHistoryDuplicates` {boolean} If `true`, when a new input line added
     to the history list duplicates an older one, this removes the older line
     from the list. **Default:** `false`.
+  * `escapeCodeTimeout` {number} The duration `readline` will wait for a
+    character (when reading an ambiguous key sequence in milliseconds one that
+    can both form a complete key sequence using the input read so far and can
+    take additional input to complete a longer key sequence).
+    **Default:** `500`.
 
 The `readline.createInterface()` method creates a new `readline.Interface`
 instance.

lib/readline.js

@@ -82,6 +82,7 @@ function Interface(input, output, completer, terminal) {
   this.isCompletionEnabled = true;
   this._sawKeyPress = false;
   this._previousKey = null;
+  this.escapeCodeTimeout = ESCAPE_CODE_TIMEOUT;
 
   EventEmitter.call(this);
   var historySize;
@@ -99,6 +100,16 @@ function Interface(input, output, completer, terminal) {
     if (input.prompt !== undefined) {
       prompt = input.prompt;
     }
+    if (input.escapeCodeTimeout !== undefined) {
+      if (Number.isFinite(input.escapeCodeTimeout)) {
+        this.escapeCodeTimeout = input.escapeCodeTimeout;
+      } else {
+        throw new ERR_INVALID_OPT_VALUE(
+          'escapeCodeTimeout',
+          this.escapeCodeTimeout
+        );
+      }
+    }
     crlfDelay = input.crlfDelay;
     input = input.input;
   }
@@ -131,7 +142,6 @@ function Interface(input, output, completer, terminal) {
   this.removeHistoryDuplicates = !!removeHistoryDuplicates;
   this.crlfDelay = crlfDelay ?
     Math.max(kMincrlfDelay, crlfDelay) : kMincrlfDelay;
-
   // Check arity, 2 - for async, 1 for sync
   if (typeof completer === 'function') {
     this.completer = completer.length === 2 ?
@@ -1022,7 +1032,10 @@ function emitKeypressEvents(stream, iface) {
             stream[ESCAPE_DECODER].next(r[i]);
             // Escape letter at the tail position
             if (r[i] === kEscape && i + 1 === r.length) {
-              timeoutId = setTimeout(escapeCodeTimeout, ESCAPE_CODE_TIMEOUT);
+              timeoutId = setTimeout(
+                escapeCodeTimeout,
+                iface ? iface.escapeCodeTimeout : ESCAPE_CODE_TIMEOUT
+              );
             }
           } catch (err) {
             // if the generator throws (it could happen in the `keypress`

test/parallel/test-readline-interface-escapecodetimeout.js

@@ -0,0 +1,46 @@
+'use strict';
+const common = require('../common');
+
+// This test ensures that the escapeCodeTimeout option set correctly
+
+const assert = require('assert');
+const readline = require('readline');
+const EventEmitter = require('events').EventEmitter;
+
+class FakeInput extends EventEmitter {
+  resume() {}
+  pause() {}
+  write() {}
+  end() {}
+}
+
+{
+  const fi = new FakeInput();
+  const rli = new readline.Interface({
+    input: fi,
+    output: fi,
+    escapeCodeTimeout: 50
+  });
+  assert.strictEqual(rli.escapeCodeTimeout, 50);
+  rli.close();
+}
+
+[
+  null,
+  {},
+  NaN,
+  '50'
+].forEach((invalidInput) => {
+  common.expectsError(() => {
+    const fi = new FakeInput();
+    const rli = new readline.Interface({
+      input: fi,
+      output: fi,
+      escapeCodeTimeout: invalidInput
+    });
+    rli.close();
+  }, {
+    type: TypeError,
+    code: 'ERR_INVALID_OPT_VALUE'
+  });
+});