diff --git a/app/logger/log_test.go b/app/logger/log_test.go
new file mode 100644
index 00000000..41e45386
--- /dev/null
+++ b/app/logger/log_test.go
@@ -0,0 +1,150 @@
+package logger
+
+import (
+	"reflect"
+	"testing"
+
+	"go.uber.org/zap"
+)
+
+func Test_getLevel1(t *testing.T) {
+	SetNamedLevels([]NamedLevel{
+		{Name: "app", Level: "debug"},
+		{Name: "app*", Level: "info"},
+		{Name: "app.sub", Level: "warn"},
+		{Name: "*", Level: "fatal"},
+	})
+
+	tests := []struct {
+		name string
+		want zap.AtomicLevel
+	}{
+		{
+			name: "app",
+			want: zap.NewAtomicLevelAt(zap.DebugLevel),
+		},
+		{
+			name: "app.aaa",
+			want: zap.NewAtomicLevelAt(zap.InfoLevel),
+		},
+		{
+			name: "app.sub",
+			want: zap.NewAtomicLevelAt(zap.InfoLevel),
+		},
+		{
+			name: "random",
+			want: zap.NewAtomicLevelAt(zap.FatalLevel),
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := getLevel(tt.name); !reflect.DeepEqual(got, tt.want) {
+				t.Errorf("getLevel() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}
+
+func Test_getLevel2(t *testing.T) {
+	SetNamedLevels([]NamedLevel{
+		{Name: "*", Level: "ERROR"},
+		{Name: "app", Level: "info"},
+		{Name: "app.sub", Level: "warn"},
+		{Name: "*", Level: "fatal"},
+	})
+
+	tests := []struct {
+		name string
+		want zap.AtomicLevel
+	}{
+		{
+			name: "app",
+			want: zap.NewAtomicLevelAt(zap.ErrorLevel),
+		},
+		{
+			name: "app.aaa",
+			want: zap.NewAtomicLevelAt(zap.ErrorLevel),
+		},
+		{
+			name: "app.sub",
+			want: zap.NewAtomicLevelAt(zap.ErrorLevel),
+		},
+		{
+			name: "random",
+			want: zap.NewAtomicLevelAt(zap.ErrorLevel),
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := getLevel(tt.name); !reflect.DeepEqual(got, tt.want) {
+				t.Errorf("getLevel() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}
+
+func Test_getLevel3(t *testing.T) {
+	SetNamedLevels([]NamedLevel{
+		{Name: "app", Level: "info"},
+		{Name: "*.sub", Level: "warn"},
+		{Name: "*", Level: "fatal"},
+	})
+
+	tests := []struct {
+		name string
+		want zap.AtomicLevel
+	}{
+		{
+			name: "app",
+			want: zap.NewAtomicLevelAt(zap.InfoLevel),
+		},
+		{
+			name: "app.sub",
+			want: zap.NewAtomicLevelAt(zap.WarnLevel),
+		},
+		{
+			name: "random",
+			want: zap.NewAtomicLevelAt(zap.FatalLevel),
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := getLevel(tt.name); !reflect.DeepEqual(got, tt.want) {
+				t.Errorf("getLevel() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}
+
+func Test_getLevel4(t *testing.T) {
+	SetNamedLevels([]NamedLevel{
+		{Name: "*", Level: "invalid"},
+		{Name: "app", Level: "info"},
+		{Name: "b", Level: "invalid"},
+	})
+
+	tests := []struct {
+		name string
+		want zap.AtomicLevel
+	}{
+		{
+			name: "app",
+			want: zap.NewAtomicLevelAt(zap.InfoLevel),
+		},
+		{
+			name: "app.sub",
+			want: zap.NewAtomicLevelAt(logger.Level()),
+		},
+		{
+			name: "b",
+			want: zap.NewAtomicLevelAt(logger.Level()),
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := getLevel(tt.name); !reflect.DeepEqual(got, tt.want) {
+				t.Errorf("getLevel() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}