Moved logic of collapsing songs into albums to model package

(it should really be called domain.... maybe will rename it later)

utils/number/number.go

@@ -0,0 +1,31 @@
+package number
+
+import "golang.org/x/exp/constraints"
+
+func Min[T constraints.Ordered](vs ...T) T {
+	if len(vs) == 0 {
+		var zero T
+		return zero
+	}
+	min := vs[0]
+	for _, v := range vs[1:] {
+		if v < min {
+			min = v
+		}
+	}
+	return min
+}
+
+func Max[T constraints.Ordered](vs ...T) T {
+	if len(vs) == 0 {
+		var zero T
+		return zero
+	}
+	max := vs[0]
+	for _, v := range vs[1:] {
+		if v > max {
+			max = v
+		}
+	}
+	return max
+}

utils/number/number_test.go

@@ -0,0 +1,38 @@
+package number_test
+
+import (
+	"testing"
+
+	"github.com/navidrome/navidrome/utils/number"
+	. "github.com/onsi/ginkgo/v2"
+	. "github.com/onsi/gomega"
+)
+
+func TestNumber(t *testing.T) {
+	RegisterFailHandler(Fail)
+	RunSpecs(t, "Number Suite")
+}
+
+var _ = Describe("Min", func() {
+	It("returns zero value if no arguments are passed", func() {
+		Expect(number.Min[int]()).To(BeZero())
+	})
+	It("returns the smallest int", func() {
+		Expect(number.Min(1, 2)).To(Equal(1))
+	})
+	It("returns the smallest float", func() {
+		Expect(number.Min(-4.1, -4.2, -4.0)).To(Equal(-4.2))
+	})
+})
+
+var _ = Describe("Max", func() {
+	It("returns zero value if no arguments are passed", func() {
+		Expect(number.Max[int]()).To(BeZero())
+	})
+	It("returns the biggest int", func() {
+		Expect(number.Max(1, 2)).To(Equal(2))
+	})
+	It("returns the biggest float", func() {
+		Expect(number.Max(-4.1, -4.2, -4.0)).To(Equal(-4.0))
+	})
+})