From 07dbeb6801063d81e6185b1dd81eef1302c11421 Mon Sep 17 00:00:00 2001
From: Joyee Cheung <joyeec9h3@gmail.com>
Date: Sat, 3 Nov 2018 03:20:23 +0800
Subject: [PATCH] console: bind methods from the prototype chain in Console

In 62232361 we made the console.Console function construct an object
with methods from Console.prototype bound to the instance, instead of
with methods found on the prototype chain to be bound on the instances,
thus breaking users overriding these methods when subclassing Console
because they are not expecting this function to construct a
namespace whose methods are not looked up from the prototype
chain.

This patch restores the previous behavior since it does not affect
the characteristics of the global console anyway. So after this patch,
the Console function still constructs normal objects with function
properties looked up from the prototype chain but bound to the
instances always.
---
 lib/console.js                         | 5 ++++-
 test/parallel/test-console-instance.js | 6 ++++++
 2 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/lib/console.js b/lib/console.js
index 2e56f7bbba5ad8..39e55c202c4f4b 100644
--- a/lib/console.js
+++ b/lib/console.js
@@ -129,7 +129,10 @@ function Console(options /* or: stdout, stderr, ignoreErrors = true */) {
   var keys = Object.keys(Console.prototype);
   for (var v = 0; v < keys.length; v++) {
     var k = keys[v];
-    this[k] = Console.prototype[k].bind(this);
+    // We have to bind the methods grabbed from the instance instead of from
+    // the prototype so that users extending the Console can override them
+    // from the prototype chain of the subclass.
+    this[k] = this[k].bind(this);
   }
 }
 
diff --git a/test/parallel/test-console-instance.js b/test/parallel/test-console-instance.js
index 87708808a8652c..e6e1e0db24d23c 100644
--- a/test/parallel/test-console-instance.js
+++ b/test/parallel/test-console-instance.js
@@ -105,10 +105,16 @@ out.write = err.write = (d) => {};
 {
   class MyConsole extends Console {
     hello() {}
+    // See if the methods on Console.prototype are overridable.
+    log() { return 'overridden'; }
   }
   const myConsole = new MyConsole(process.stdout);
   assert.strictEqual(typeof myConsole.hello, 'function');
   assert.ok(myConsole instanceof Console);
+  assert.strictEqual(myConsole.log(), 'overridden');
+
+  const log = myConsole.log;
+  assert.strictEqual(log(), 'overridden');
 }
 
 // Instance that does not ignore the stream errors.