feat: add new utility functions

arguments.go

@@ -8,6 +8,8 @@
 
 package f
 
+import "fmt"
+
 // Must should be used to wrap a call to a function returning a value and an error.
 // Must returns the value if the errors is nil, or panics otherwise.
 func Must[T any](val T, err error) T {
@@ -16,3 +18,10 @@ func Must[T any](val T, err error) T {
 	}
 	return val
 }
+
+// Assert panics if condition is false.
+func Assert(condition bool, msg string, args ...any) {
+	if !condition {
+		panic(fmt.Sprintf(msg, args...))
+	}
+}

arguments_test.go

@@ -0,0 +1,35 @@
+package f_test
+
+import (
+	"fmt"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+
+	f "go.bug.st/f"
+)
+
+func TestMust(t *testing.T) {
+	t.Run("no error", func(t *testing.T) {
+		assert.Equal(t, 12, f.Must(12, nil))
+	})
+
+	t.Run("error", func(t *testing.T) {
+		want := fmt.Errorf("this is an error")
+		assert.PanicsWithValue(t, want.Error(), func() {
+			f.Must(0, want)
+		})
+	})
+}
+
+func TestAssert(t *testing.T) {
+	t.Run("true", func(_ *testing.T) {
+		f.Assert(true, "should not panic")
+	})
+
+	t.Run("false", func(t *testing.T) {
+		assert.PanicsWithValue(t, "should panic", func() {
+			f.Assert(false, "should panic")
+		})
+	})
+}

ptr.go

@@ -0,0 +1,16 @@
+package f
+
+// Ptr returns a pointer to v.
+func Ptr[T any](v T) *T {
+	return &v
+}
+
+// UnwrapOrDefault returns the ptr value if it is not nil, otherwise returns the zero value.
+func UnwrapOrDefault[T any](ptr *T) T {
+	if ptr != nil {
+		return *ptr
+	}
+
+	var zero T
+	return zero
+}

ptr_test.go

@@ -0,0 +1,30 @@
+package f_test
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+
+	f "go.bug.st/f"
+)
+
+func TestPtr(t *testing.T) {
+	t.Run("int", func(t *testing.T) {
+		assert.Equal(t, 12, *f.Ptr(12))
+	})
+
+	t.Run("string", func(t *testing.T) {
+		assert.Equal(t, "hello", *f.Ptr("hello"))
+	})
+}
+
+func TestUnwrapOrDefault(t *testing.T) {
+	t.Run("not nil", func(t *testing.T) {
+		given := 12
+		assert.Equal(t, 12, f.UnwrapOrDefault(&given))
+	})
+
+	t.Run("nil", func(t *testing.T) {
+		assert.Equal(t, "", f.UnwrapOrDefault[string](nil))
+	})
+}