From 6e5ec0583c83b3d97b001beb8598c91a01d37139 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Sebastian=20D=C3=B6ll?= <sebastian@katallaxie.dev>
Date: Fri, 25 Oct 2024 20:26:40 +0000
Subject: [PATCH] feat: add exists map

---
 mapx/mapx.go      |  6 ++++++
 mapx/mapx_test.go | 10 ++++++++++
 2 files changed, 16 insertions(+)

diff --git a/mapx/mapx.go b/mapx/mapx.go
index 4019ec1..8183b1b 100644
--- a/mapx/mapx.go
+++ b/mapx/mapx.go
@@ -19,3 +19,9 @@ func Keep[T1 comparable, T2 any](m map[T1]T2, keys ...T1) {
 		}
 	}
 }
+
+// Exists checks if a key exists in a map.
+func Exists[T1 comparable, T2 any](m map[T1]T2, key T1) bool {
+	_, ok := m[key]
+	return ok
+}
diff --git a/mapx/mapx_test.go b/mapx/mapx_test.go
index 5a7f58b..1c4bfad 100644
--- a/mapx/mapx_test.go
+++ b/mapx/mapx_test.go
@@ -32,3 +32,13 @@ func TestKeep(t *testing.T) {
 		2: "two",
 	}, m)
 }
+
+func TestExists(t *testing.T) {
+	m := map[int]string{
+		1: "one",
+		2: "two",
+		3: "three",
+	}
+	assert.True(t, mapx.Exists(m, 2))
+	assert.False(t, mapx.Exists(m, 4))
+}