From f7abe3d156f8039c497c5bdf28e0b7ccf2f94d25 Mon Sep 17 00:00:00 2001
From: Csaba Tuncsik <csaba@n8n.io>
Date: Tue, 1 Nov 2022 23:01:14 +0100
Subject: [PATCH] perf(editor): improve array intersection utility function

---
 packages/editor-ui/src/utils.test.ts | 41 ++++++++++++++++++++++++++++
 packages/editor-ui/src/utils.ts      |  6 +++-
 2 files changed, 46 insertions(+), 1 deletion(-)
 create mode 100644 packages/editor-ui/src/utils.test.ts

diff --git a/packages/editor-ui/src/utils.test.ts b/packages/editor-ui/src/utils.test.ts
new file mode 100644
index 0000000000000..1d2aada70aa4c
--- /dev/null
+++ b/packages/editor-ui/src/utils.test.ts
@@ -0,0 +1,41 @@
+import { isEmpty, intersection } from "@/utils";
+
+describe("Utils", () => {
+	describe("isEmpty", () => {
+		it.each([
+			[undefined, true],
+			[null, true],
+			[{}, true],
+			[{ a: {}}, true],
+			[{ a: { b: []}}, true],
+			[{ a: { b: [1]}}, false],
+			[[], true],
+			[[{}, {}, {}], true],
+			[[{}, null, false], true],
+			[[{}, null, false, 1], false],
+			[[[], [], []], true],
+			["", true],
+			["0", false],
+			[0, false],
+			[1, false],
+			[false, true],
+			[true, false],
+		])(`for value %s should return %s`, (value, expected) => {
+			expect(isEmpty(value)).toBe(expected);
+		});
+	});
+
+	describe("intersection", () => {
+		it("should return the intersection of two arrays", () => {
+			expect(intersection([1, 2, 3], [2, 3, 4])).toEqual([2, 3]);
+		});
+
+		it("should return the intersection of two arrays without duplicates", () => {
+			expect(intersection([1, 2, 2, 3], [2, 2, 3, 4])).toEqual([2, 3]);
+		});
+
+		it("should return the intersection of four arrays without duplicates", () => {
+			expect(intersection([1, 2, 2, 3, 4], [2, 3, 3, 4], [2, 1, 5, 4, 4, 1], [2, 4, 5, 5, 6, 7])).toEqual([2, 4]);
+		});
+	});
+});
diff --git a/packages/editor-ui/src/utils.ts b/packages/editor-ui/src/utils.ts
index 7880c79de9a09..15a34e8cea37e 100644
--- a/packages/editor-ui/src/utils.ts
+++ b/packages/editor-ui/src/utils.ts
@@ -57,4 +57,8 @@ export const isEmpty = (value?: unknown): boolean => {
 	return false;
 };
 
-export const intersection = <T>(a: T[], b:T[]): T[] => a.filter(Set.prototype.has, new Set(b));
+export const intersection = <T>(...arrays: T[][]): T[] => {
+	const [a, b, ...rest] = arrays;
+	const ab = a.filter(v => b.includes(v));
+	return [...new Set(rest.length ? intersection(ab, ...rest) : ab)];
+};