From 127b5f89130ca4b7653473eb0ae17cc1dd207d91 Mon Sep 17 00:00:00 2001
From: make-github-pseudonymous-again
 <5165674+make-github-pseudonymous-again@users.noreply.github.com>
Date: Sun, 13 Nov 2022 18:55:09 +0100
Subject: [PATCH] :sparkles: feat: Refactor _remove as _erase via generic
 _concat.

---
 src/_concat.js     |  4 ++--
 src/_erase.js      | 14 ++++++++++++++
 src/_remove.js     |  4 ++--
 src/index.js       |  1 +
 test/src/remove.js | 11 +++++++++++
 5 files changed, 30 insertions(+), 4 deletions(-)
 create mode 100644 src/_erase.js
 create mode 100644 test/src/remove.js

diff --git a/src/_concat.js b/src/_concat.js
index a86cf7c..ca14d4a 100644
--- a/src/_concat.js
+++ b/src/_concat.js
@@ -8,8 +8,8 @@ import Node from './Node.js';
  * @param {Node} y First node of second input list.
  */
 export default function _concat(z, y) {
-	assert(z instanceof Node && z.next === null);
-	assert(y instanceof Node && y.prev === null);
+	assert(z instanceof Node);
+	assert(y instanceof Node);
 	z.next = y;
 	y.prev = z;
 }
diff --git a/src/_erase.js b/src/_erase.js
new file mode 100644
index 0000000..d016cfb
--- /dev/null
+++ b/src/_erase.js
@@ -0,0 +1,14 @@
+import assert from 'assert';
+import Node from './Node.js';
+import _concat from './_concat.js';
+
+/**
+ * Erase range [x, y) from list. Range cannot be empty.
+ *
+ * @param {Node} x Inclusive beginning of range to erase.
+ * @param {Node} y Exclusive end of range to erase.
+ */
+export default function _erase(x, y) {
+	assert(x instanceof Node);
+	_concat(x.prev, y);
+}
diff --git a/src/_remove.js b/src/_remove.js
index f94c1b3..6766625 100644
--- a/src/_remove.js
+++ b/src/_remove.js
@@ -1,5 +1,6 @@
 import assert from 'assert';
 import Node from './Node.js';
+import _erase from './_erase.js';
 
 /**
  * Removes input {@link Node} from its list. Cannot be first or last, use
@@ -12,6 +13,5 @@ import Node from './Node.js';
  */
 export default function _remove(x) {
 	assert(x instanceof Node);
-	x.prev.next = x.next;
-	x.next.prev = x.prev;
+	_erase(x, x.next);
 }
diff --git a/src/index.js b/src/index.js
index 043019f..6654aa7 100644
--- a/src/index.js
+++ b/src/index.js
@@ -1,5 +1,6 @@
 export {default as Node} from './Node.js';
 export {default as _concat} from './_concat.js';
+export {default as _erase} from './_erase.js';
 export {default as _extend} from './_extend.js';
 export {default as _iter} from './_iter.js';
 export {default as _iter_fast} from './_iter_fast.js';
diff --git a/test/src/remove.js b/test/src/remove.js
new file mode 100644
index 0000000..6b506bb
--- /dev/null
+++ b/test/src/remove.js
@@ -0,0 +1,11 @@
+import test from 'ava';
+
+import {list} from '@iterable-iterator/list';
+
+import {values, from, _remove} from '#module';
+
+test('_remove', (t) => {
+	const l = from('abc');
+	_remove(l.next);
+	t.is(list(values(l)).join(''), 'ac');
+});