From 3b4c26fa4dbb29cb9413a27949a21bb093765ff6 Mon Sep 17 00:00:00 2001
From: lucarin91 <lucarin@protonmail.com>
Date: Wed, 18 Sep 2024 15:38:15 +0200
Subject: [PATCH] feat: add new utility functions

---
 arguments.go      |  9 +++++++++
 arguments_test.go | 35 +++++++++++++++++++++++++++++++++++
 ptr.go            | 16 ++++++++++++++++
 ptr_test.go       | 30 ++++++++++++++++++++++++++++++
 4 files changed, 90 insertions(+)
 create mode 100644 arguments_test.go
 create mode 100644 ptr.go
 create mode 100644 ptr_test.go

diff --git a/arguments.go b/arguments.go
index 26d09c7..de8ce17 100644
--- a/arguments.go
+++ b/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...))
+	}
+}
diff --git a/arguments_test.go b/arguments_test.go
new file mode 100644
index 0000000..406210c
--- /dev/null
+++ b/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")
+		})
+	})
+}
diff --git a/ptr.go b/ptr.go
new file mode 100644
index 0000000..2fc4793
--- /dev/null
+++ b/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
+}
diff --git a/ptr_test.go b/ptr_test.go
new file mode 100644
index 0000000..db79fad
--- /dev/null
+++ b/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))
+	})
+}