feat: add Must4, add tests

Author: roman-vanesyan

must/must.go

@@ -8,23 +8,32 @@ func Must1(err error) {
 	}
 }
 
-// Must panics if err is not nil and otherwise returns value.
+// Must panics if err is not nil and otherwise returns v.
 //
 // It is named as Must without a number suffix cause functions with
 // two parameters are most common.
-func Must[T any](value T, err error) T {
+func Must[T any](v T, err error) T {
 	if err != nil {
 		panic(err)
 	}
 
-	return value
+	return v
 }
 
-// Must3 panics if err is not nil, otherwise returns value1 and value2.
-func Must3[T1 any, T2 any](value1 T1, value2 T2, err error) (T1, T2) {
+// Must3 panics if err is not nil, otherwise returns v1 and v2.
+func Must3[T1 any, T2 any](v1 T1, v2 T2, err error) (T1, T2) {
 	if err != nil {
 		panic(err)
 	}
 
-	return value1, value2
+	return v1, v2
+}
+
+// Must4 panics if err is not nil, otherwise returns v1, v2 and v3.
+func Must4[T1 any, T2 any, T3 any](v1 T1, v2 T2, v3 T3, err error) (T1, T2, T3) {
+	if err != nil {
+		panic(err)
+	}
+
+	return v1, v2, v3
 }

must/must_test.go

@@ -0,0 +1,56 @@
+package must
+
+import (
+	"errors"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestMust1(t *testing.T) {
+	t.Run("should return normally", func(t *testing.T) {
+		assert.NotPanics(t, func() { Must1(nil) })
+	})
+	t.Run("should panic on error", func(t *testing.T) {
+		assert.Panics(t, func() { Must1(errors.New("panic")) })
+	})
+}
+
+func TestMust(t *testing.T) {
+	t.Run("should return normally", func(t *testing.T) {
+		var v1 int
+		assert.NotPanics(t, func() { v1 = Must(123, nil) })
+		assert.Equal(t, v1, 123)
+	})
+	t.Run("should panic on error", func(t *testing.T) {
+		assert.Panics(t, func() { Must(123, errors.New("panic")) })
+	})
+}
+
+func TestMust3(t *testing.T) {
+	t.Run("should return normally", func(t *testing.T) {
+		var v1 int
+		var v2 string
+		assert.NotPanics(t, func() { v1, v2 = Must3(123, "my string", nil) })
+		assert.Equal(t, v1, 123)
+		assert.Equal(t, v2, "my string")
+	})
+	t.Run("should panic on error", func(t *testing.T) {
+		assert.Panics(t, func() { Must3(123, "my string", errors.New("panic")) })
+	})
+}
+
+func TestMust4(t *testing.T) {
+	t.Run("should return normally", func(t *testing.T) {
+		var v1 int
+		var v2 string
+		var v3 bool
+		assert.NotPanics(t, func() { v1, v2, v3 = Must4(123, "my string", false, nil) })
+		assert.Equal(t, v1, 123)
+		assert.Equal(t, v2, "my string")
+		assert.Equal(t, v3, false)
+	})
+	t.Run("should panic on error", func(t *testing.T) {
+		assert.Panics(t, func() { Must4(123, "my string", false, errors.New("panic")) })
+	})
+}