From c694660fb3c299f33e97b2ab00ccdee53863fa6c Mon Sep 17 00:00:00 2001
From: Quillraven <quillraven@gmail.com>
Date: Mon, 23 Dec 2024 00:52:11 +0100
Subject: [PATCH] add count with predicate to family

---
 src/commonMain/kotlin/com/github/quillraven/fleks/family.kt  | 5 +++++
 .../com/github/quillraven/fleks/FamilyBagFunctionsTest.kt    | 5 +++++
 2 files changed, 10 insertions(+)

diff --git a/src/commonMain/kotlin/com/github/quillraven/fleks/family.kt b/src/commonMain/kotlin/com/github/quillraven/fleks/family.kt
index a0e6a5b..737b2c2 100644
--- a/src/commonMain/kotlin/com/github/quillraven/fleks/family.kt
+++ b/src/commonMain/kotlin/com/github/quillraven/fleks/family.kt
@@ -254,6 +254,11 @@ data class Family(
      */
     fun none(predicate: (Entity) -> Boolean): Boolean = mutableEntities.none(predicate)
 
+    /**
+     * Returns the number of [entities][Entity] matching the given [predicate].
+     */
+    fun count(predicate: (Entity) -> Boolean): Int = mutableEntities.count(predicate)
+
     /**
      * Returns a [Map] containing key-value pairs provided by the [transform] function applied to
      * each [entity][Entity] of the family.
diff --git a/src/commonTest/kotlin/com/github/quillraven/fleks/FamilyBagFunctionsTest.kt b/src/commonTest/kotlin/com/github/quillraven/fleks/FamilyBagFunctionsTest.kt
index 1d4fc48..1f2ce4d 100644
--- a/src/commonTest/kotlin/com/github/quillraven/fleks/FamilyBagFunctionsTest.kt
+++ b/src/commonTest/kotlin/com/github/quillraven/fleks/FamilyBagFunctionsTest.kt
@@ -48,6 +48,11 @@ class FamilyBagFunctionsTest {
         assertFalse(testFamily.none { it.id == 0 })
     }
 
+    @Test
+    fun testCount() {
+        assertEquals(1, testFamily.count { it.id == 0 })
+    }
+
     @Test
     fun testAssociate() {
         val expected = mapOf(testEntity1 to 0, testEntity2 to 1)