test: add tests for the 'IsNilOrZero' function

common/compare_test.go

@@ -0,0 +1,350 @@
+package common
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestIsNilOrZero(t *testing.T) {
+	t.Run("nil pointer returns true", func(t *testing.T) {
+		var intPtr *int
+		assert.True(t, IsNilOrZero(intPtr))
+
+		var strPtr *string
+		assert.True(t, IsNilOrZero(strPtr))
+
+		var boolPtr *bool
+		assert.True(t, IsNilOrZero(boolPtr))
+
+		var floatPtr *float64
+		assert.True(t, IsNilOrZero(floatPtr))
+	})
+
+	t.Run("pointer to zero value returns true", func(t *testing.T) {
+		t.Run("int zero", func(t *testing.T) {
+			val := 0
+			assert.True(t, IsNilOrZero(&val))
+		})
+
+		t.Run("string zero", func(t *testing.T) {
+			val := ""
+			assert.True(t, IsNilOrZero(&val))
+		})
+
+		t.Run("bool zero", func(t *testing.T) {
+			val := false
+			assert.True(t, IsNilOrZero(&val))
+		})
+
+		t.Run("float64 zero", func(t *testing.T) {
+			val := 0.0
+			assert.True(t, IsNilOrZero(&val))
+		})
+
+		t.Run("uint zero", func(t *testing.T) {
+			val := uint(0)
+			assert.True(t, IsNilOrZero(&val))
+		})
+	})
+
+	t.Run("pointer to non-zero value returns false", func(t *testing.T) {
+		t.Run("int non-zero", func(t *testing.T) {
+			val := 42
+			assert.False(t, IsNilOrZero(&val))
+
+			negVal := -1
+			assert.False(t, IsNilOrZero(&negVal))
+		})
+
+		t.Run("string non-zero", func(t *testing.T) {
+			val := "hello"
+			assert.False(t, IsNilOrZero(&val))
+
+			spaceVal := " "
+			assert.False(t, IsNilOrZero(&spaceVal))
+		})
+
+		t.Run("bool non-zero", func(t *testing.T) {
+			val := true
+			assert.False(t, IsNilOrZero(&val))
+		})
+
+		t.Run("float64 non-zero", func(t *testing.T) {
+			val := 3.14
+			assert.False(t, IsNilOrZero(&val))
+
+			negVal := -2.5
+			assert.False(t, IsNilOrZero(&negVal))
+		})
+
+		t.Run("uint non-zero", func(t *testing.T) {
+			val := uint(100)
+			assert.False(t, IsNilOrZero(&val))
+		})
+	})
+
+	t.Run("works with all integer types", func(t *testing.T) {
+		t.Run("int8", func(t *testing.T) {
+			var nilPtr *int8
+			assert.True(t, IsNilOrZero(nilPtr))
+
+			zero := int8(0)
+			assert.True(t, IsNilOrZero(&zero))
+
+			nonZero := int8(127)
+			assert.False(t, IsNilOrZero(&nonZero))
+		})
+
+		t.Run("int16", func(t *testing.T) {
+			var nilPtr *int16
+			assert.True(t, IsNilOrZero(nilPtr))
+
+			zero := int16(0)
+			assert.True(t, IsNilOrZero(&zero))
+
+			nonZero := int16(1000)
+			assert.False(t, IsNilOrZero(&nonZero))
+		})
+
+		t.Run("int32", func(t *testing.T) {
+			var nilPtr *int32
+			assert.True(t, IsNilOrZero(nilPtr))
+
+			zero := int32(0)
+			assert.True(t, IsNilOrZero(&zero))
+
+			nonZero := int32(100000)
+			assert.False(t, IsNilOrZero(&nonZero))
+		})
+
+		t.Run("int64", func(t *testing.T) {
+			var nilPtr *int64
+			assert.True(t, IsNilOrZero(nilPtr))
+
+			zero := int64(0)
+			assert.True(t, IsNilOrZero(&zero))
+
+			nonZero := int64(9223372036854775807)
+			assert.False(t, IsNilOrZero(&nonZero))
+		})
+
+		t.Run("uint8", func(t *testing.T) {
+			var nilPtr *uint8
+			assert.True(t, IsNilOrZero(nilPtr))
+
+			zero := uint8(0)
+			assert.True(t, IsNilOrZero(&zero))
+
+			nonZero := uint8(255)
+			assert.False(t, IsNilOrZero(&nonZero))
+		})
+
+		t.Run("uint16", func(t *testing.T) {
+			var nilPtr *uint16
+			assert.True(t, IsNilOrZero(nilPtr))
+
+			zero := uint16(0)
+			assert.True(t, IsNilOrZero(&zero))
+
+			nonZero := uint16(65535)
+			assert.False(t, IsNilOrZero(&nonZero))
+		})
+
+		t.Run("uint32", func(t *testing.T) {
+			var nilPtr *uint32
+			assert.True(t, IsNilOrZero(nilPtr))
+
+			zero := uint32(0)
+			assert.True(t, IsNilOrZero(&zero))
+
+			nonZero := uint32(4294967295)
+			assert.False(t, IsNilOrZero(&nonZero))
+		})
+
+		t.Run("uint64", func(t *testing.T) {
+			var nilPtr *uint64
+			assert.True(t, IsNilOrZero(nilPtr))
+
+			zero := uint64(0)
+			assert.True(t, IsNilOrZero(&zero))
+
+			nonZero := uint64(18446744073709551615)
+			assert.False(t, IsNilOrZero(&nonZero))
+		})
+	})
+
+	t.Run("works with float types", func(t *testing.T) {
+		t.Run("float32", func(t *testing.T) {
+			var nilPtr *float32
+			assert.True(t, IsNilOrZero(nilPtr))
+
+			zero := float32(0.0)
+			assert.True(t, IsNilOrZero(&zero))
+
+			nonZero := float32(1.5)
+			assert.False(t, IsNilOrZero(&nonZero))
+		})
+
+		t.Run("float64", func(t *testing.T) {
+			var nilPtr *float64
+			assert.True(t, IsNilOrZero(nilPtr))
+
+			zero := float64(0.0)
+			assert.True(t, IsNilOrZero(&zero))
+
+			nonZero := float64(123.456)
+			assert.False(t, IsNilOrZero(&nonZero))
+		})
+	})
+
+	t.Run("works with struct types", func(t *testing.T) {
+		type Person struct {
+			Name string
+			Age  int
+		}
+
+		t.Run("nil struct pointer", func(t *testing.T) {
+			var nilPtr *Person
+			assert.True(t, IsNilOrZero(nilPtr))
+		})
+
+		t.Run("pointer to zero struct", func(t *testing.T) {
+			zero := Person{}
+			assert.True(t, IsNilOrZero(&zero))
+		})
+
+		t.Run("pointer to non-zero struct", func(t *testing.T) {
+			nonZero := Person{Name: "John", Age: 30}
+			assert.False(t, IsNilOrZero(&nonZero))
+
+			partiallyFilled := Person{Name: "Jane"}
+			assert.False(t, IsNilOrZero(&partiallyFilled))
+
+			onlyAge := Person{Age: 25}
+			assert.False(t, IsNilOrZero(&onlyAge))
+		})
+	})
+
+	t.Run("works with array types", func(t *testing.T) {
+		t.Run("nil array pointer", func(t *testing.T) {
+			var nilPtr *[3]int
+			assert.True(t, IsNilOrZero(nilPtr))
+		})
+
+		t.Run("pointer to zero array", func(t *testing.T) {
+			zero := [3]int{0, 0, 0}
+			assert.True(t, IsNilOrZero(&zero))
+		})
+
+		t.Run("pointer to non-zero array", func(t *testing.T) {
+			nonZero := [3]int{1, 2, 3}
+			assert.False(t, IsNilOrZero(&nonZero))
+
+			partiallyFilled := [3]int{1, 0, 0}
+			assert.False(t, IsNilOrZero(&partiallyFilled))
+		})
+	})
+
+	t.Run("edge cases", func(t *testing.T) {
+		t.Run("pointer to negative number", func(t *testing.T) {
+			val := -1
+			assert.False(t, IsNilOrZero(&val))
+		})
+
+		t.Run("pointer to whitespace string", func(t *testing.T) {
+			val := " "
+			assert.False(t, IsNilOrZero(&val))
+
+			tab := "\t"
+			assert.False(t, IsNilOrZero(&tab))
+
+			newline := "\n"
+			assert.False(t, IsNilOrZero(&newline))
+		})
+
+		t.Run("pointer to byte (uint8) zero", func(t *testing.T) {
+			val := byte(0)
+			assert.True(t, IsNilOrZero(&val))
+
+			nonZero := byte('A')
+			assert.False(t, IsNilOrZero(&nonZero))
+		})
+
+		t.Run("pointer to rune (int32) zero", func(t *testing.T) {
+			val := rune(0)
+			assert.True(t, IsNilOrZero(&val))
+
+			nonZero := rune('Z')
+			assert.False(t, IsNilOrZero(&nonZero))
+		})
+	})
+
+	t.Run("consistency with ToPtr", func(t *testing.T) {
+		t.Run("ToPtr of zero value is nil or zero", func(t *testing.T) {
+			intPtr := ToPtr(0)
+			assert.True(t, IsNilOrZero(intPtr))
+
+			strPtr := ToPtr("")
+			assert.True(t, IsNilOrZero(strPtr))
+
+			boolPtr := ToPtr(false)
+			assert.True(t, IsNilOrZero(boolPtr))
+		})
+
+		t.Run("ToPtr of non-zero value is not nil or zero", func(t *testing.T) {
+			intPtr := ToPtr(42)
+			assert.False(t, IsNilOrZero(intPtr))
+
+			strPtr := ToPtr("hello")
+			assert.False(t, IsNilOrZero(strPtr))
+
+			boolPtr := ToPtr(true)
+			assert.False(t, IsNilOrZero(boolPtr))
+		})
+	})
+
+	t.Run("real-world usage scenarios", func(t *testing.T) {
+		t.Run("optional configuration value", func(t *testing.T) {
+			type Config struct {
+				Port    *int
+				Timeout *int
+			}
+
+			// No port configured (nil)
+			config1 := Config{}
+			assert.True(t, IsNilOrZero(config1.Port))
+
+			// Port explicitly set to 0
+			zero := 0
+			config2 := Config{Port: &zero}
+			assert.True(t, IsNilOrZero(config2.Port))
+
+			// Port configured to 8080
+			port := 8080
+			config3 := Config{Port: &port}
+			assert.False(t, IsNilOrZero(config3.Port))
+		})
+
+		t.Run("optional string field", func(t *testing.T) {
+			type User struct {
+				Name     string
+				Nickname *string
+			}
+
+			// No nickname provided
+			user1 := User{Name: "John"}
+			assert.True(t, IsNilOrZero(user1.Nickname))
+
+			// Nickname explicitly empty
+			emptyNick := ""
+			user2 := User{Name: "Jane", Nickname: &emptyNick}
+			assert.True(t, IsNilOrZero(user2.Nickname))
+
+			// Nickname provided
+			nick := "Johnny"
+			user3 := User{Name: "John", Nickname: &nick}
+			assert.False(t, IsNilOrZero(user3.Nickname))
+		})
+	})
+}