💥 feat(RedBlackTree#get)!: Return undefined when key is missing.

Fixes #109.

BREAKING CHANGE: This breaks dependents relying on #get returning null.

Author: make-github-pseudonymous-again

Diff for: src/types/RedBlackTree.js

@@ -89,7 +89,7 @@ export default class RedBlackTree {
 	 */
 	get(key) {
 		const node = this._search(key);
-		return node === null ? null : node.key;
+		return node === null ? undefined : node.key;
 	}
 
 	/**

Diff for: test/src/RedBlackTree/get.js

@@ -10,7 +10,7 @@ for (const compare of [increasing, decreasing]) {
 	test(`RedBlackTree::get [${compare.name}]`, (t) => {
 		const tree = RedBlackTree.empty(compare);
 
-		t.is(tree.get(0), null);
+		t.true(tree.get(0) === undefined);
 
 		const n = 10000;
 		const reference = [];
@@ -26,7 +26,7 @@ for (const compare of [increasing, decreasing]) {
 			t.deepEqual(tree.get(x), x);
 		}
 
-		t.is(tree.get(-1), null);
-		t.is(tree.get(n), null);
+		t.true(tree.get(-1) === undefined);
+		t.true(tree.get(n) === undefined);
 	});
 }

Diff for: test/src/RedBlackTree/remove.js

@@ -28,7 +28,7 @@ const macro = (t, reference) => {
 	for (const i of range(m)) {
 		const x = reference[i];
 		t.true(tree.remove(x));
-		t.true(tree.get(x) === null);
+		t.true(tree.get(x) === undefined);
 	}
 
 	const _rest = iter(reference);
@@ -46,7 +46,7 @@ const macro = (t, reference) => {
 
 	for (const i of range(m)) {
 		const x = reference[i];
-		t.true(tree.get(x) === null);
+		t.true(tree.get(x) === undefined);
 		tree.add(x);
 		t.true(tree.get(x) === x);
 	}
@@ -60,7 +60,7 @@ const macro = (t, reference) => {
 	for (const i of range(n)) {
 		const x = reference[i];
 		t.true(tree.remove(x));
-		t.true(tree.get(x) === null);
+		t.true(tree.get(x) === undefined);
 	}
 
 	t.deepEqual(list(tree), [], 'tree is empty');