diff --git a/internal/changelog/filter_test.go b/internal/changelog/filter_test.go
new file mode 100644
index 0000000..1afef85
--- /dev/null
+++ b/internal/changelog/filter_test.go
@@ -0,0 +1,100 @@
+package changelog
+
+import (
+	"testing"
+
+	"github.com/haunt98/changeloguru/internal/convention"
+	"github.com/stretchr/testify/assert"
+)
+
+func TestFilter(t *testing.T) {
+	tests := []struct {
+		name    string
+		commits []convention.Commit
+		scopes  map[string]struct{}
+		want    map[string][]convention.Commit
+	}{
+		{
+			name: "without scopes",
+			commits: []convention.Commit{
+				{
+					RawHeader: "feature A",
+					Type:      convention.FeatType,
+				},
+				{
+					RawHeader: "fix B",
+					Type:      convention.FixType,
+				},
+				{
+					RawHeader: "build",
+					Type:      convention.BuildType,
+				},
+			},
+			want: map[string][]convention.Commit{
+				addedType: {
+					{
+						RawHeader: "feature A",
+						Type:      convention.FeatType,
+					},
+				},
+				fixedType: {
+					{
+						RawHeader: "fix B",
+						Type:      convention.FixType,
+					},
+				},
+				othersType: {
+					{
+						RawHeader: "build",
+						Type:      convention.BuildType,
+					},
+				},
+			},
+		},
+		{
+			name: "with scopes",
+			commits: []convention.Commit{
+				{
+					RawHeader: "feature A",
+					Type:      convention.FeatType,
+					Scope:     "A",
+				},
+				{
+					RawHeader: "fix B",
+					Type:      convention.FixType,
+					Scope:     "B",
+				},
+				{
+					RawHeader: "build",
+					Type:      convention.BuildType,
+				},
+			},
+			scopes: map[string]struct{}{
+				"A": {},
+			},
+			want: map[string][]convention.Commit{
+				addedType: {
+					{
+						RawHeader: "feature A",
+						Type:      convention.FeatType,
+						Scope:     "A",
+					},
+				},
+				fixedType: {},
+				othersType: {
+					{
+						RawHeader: "build",
+						Type:      convention.BuildType,
+					},
+				},
+			},
+		},
+	}
+
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			got := filter(tc.commits, tc.scopes)
+			assert.Equal(t, tc.want, got)
+		})
+	}
+}