From ad518df9936e7a4cc783ee3dd9d66319c3112bf2 Mon Sep 17 00:00:00 2001
From: Ruidy <rnemausat@newstore.com>
Date: Tue, 28 Dec 2021 19:36:36 -0400
Subject: [PATCH] feat: filter

---
 filter.go      | 10 ++++++++++
 filter_test.go | 17 +++++++++++++++++
 go.mod         |  4 ++--
 go.sum         |  4 +---
 4 files changed, 30 insertions(+), 5 deletions(-)
 create mode 100644 filter.go
 create mode 100644 filter_test.go

diff --git a/filter.go b/filter.go
new file mode 100644
index 0000000..f277cb4
--- /dev/null
+++ b/filter.go
@@ -0,0 +1,10 @@
+package underscore
+
+func Filter[T any](values []T, predicate func(T) bool) (res []T) {
+	for _, v := range values {
+		if predicate(v) {
+			res = append(res, v)
+		}
+	}
+	return res
+}
diff --git a/filter_test.go b/filter_test.go
new file mode 100644
index 0000000..fdd8e6b
--- /dev/null
+++ b/filter_test.go
@@ -0,0 +1,17 @@
+package underscore_test
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+
+	u "github.com/rjNemo/underscore"
+)
+
+func TestFilter(t *testing.T) {
+	nums := []int{0, 1, 2, 3, 4, 5, 6, 7, 8, 9}
+	isEven := func(n int) bool { return n%2 == 0 }
+
+	want := []int{0, 2, 4, 6, 8}
+	assert.Equal(t, want, u.Filter(nums, isEven))
+}
diff --git a/go.mod b/go.mod
index 0066efa..98452a0 100644
--- a/go.mod
+++ b/go.mod
@@ -2,10 +2,10 @@ module github.com/rjNemo/underscore
 
 go 1.18
 
+require github.com/stretchr/testify v1.7.0
+
 require (
 	github.com/davecgh/go-spew v1.1.1 // indirect
 	github.com/pmezard/go-difflib v1.0.0 // indirect
-	github.com/stretchr/objx v0.3.0 // indirect
-	github.com/stretchr/testify v1.7.0 // indirect
 	gopkg.in/yaml.v3 v3.0.0-20210107192922-496545a6307b // indirect
 )
diff --git a/go.sum b/go.sum
index 8d71661..c221f64 100644
--- a/go.sum
+++ b/go.sum
@@ -4,11 +4,9 @@ github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSs
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
-github.com/stretchr/objx v0.3.0 h1:NGXK3lHquSN08v5vWalVI/L8XU9hdzE/G6xsrze47As=
-github.com/stretchr/objx v0.3.0/go.mod h1:qt09Ya8vawLte6SNmTgCsAVtYtaKzEcn8ATUoHMkEqE=
-github.com/stretchr/testify v1.3.0/go.mod h1:M5WIy9Dh21IEIfnGCwXGc5bZfKNJtfHm1UVUgZn+9EI=
 github.com/stretchr/testify v1.7.0 h1:nwc3DEeHmmLAfoZucVR881uASk0Mfjw8xYJ99tb5CcY=
 github.com/stretchr/testify v1.7.0/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
 gopkg.in/yaml.v3 v3.0.0-20210107192922-496545a6307b h1:h8qDotaEPuJATrMmW04NCwg7v22aHH28wwpauUhK9Oo=