Add Expect to option and result

Author: BooleanCat

option/option.go

@@ -86,3 +86,13 @@ func (o Option[T]) IsNone() bool {
 func (o Option[T]) Value() (T, bool) {
 	return o.value, o.present
 }
+
+// Expect returns the underlying value for a [Some] variant, or panics with the
+// provided message for a [None] variant.
+func (o Option[T]) Expect(message string) T {
+	if o.present {
+		return o.value
+	}
+
+	panic(message)
+}

option/option_test.go

@@ -72,6 +72,12 @@ func ExampleOption_Value() {
 	// true
 }
 
+func ExampleOption_Expect() {
+	fmt.Println(option.Some(4).Expect("oops"))
+
+	// Output: 4
+}
+
 func TestSomeStringer(t *testing.T) {
 	assert.Equal(t, fmt.Sprintf("%s", option.Some("foo")), "Some(foo)") //nolint:gosimple
 	assert.Equal(t, fmt.Sprintf("%s", option.Some(42)), "Some(42)")     //nolint:gosimple
@@ -139,3 +145,16 @@ func TestNoneValue(t *testing.T) {
 	assert.Equal(t, value, 0)
 	assert.False(t, ok)
 }
+
+func TestSomeExpect(t *testing.T) {
+	assert.Equal(t, option.Some(42).Expect("oops"), 42)
+}
+
+func TestNoneExpect(t *testing.T) {
+	defer func() {
+		assert.Equal(t, fmt.Sprint(recover()), "oops")
+	}()
+
+	option.None[int]().Expect("oops")
+	t.Error("did not panic")
+}

result/result.go

@@ -97,3 +97,13 @@ func (r Result[T]) UnwrapErr() error {
 
 	return r.err
 }
+
+// Expect returns the underlying value of an [Ok] variant, or panics with the
+// provided message if called on an [Err] variant.
+func (r Result[T]) Expect(message string) T {
+	if r.err == nil {
+		return r.value
+	}
+
+	panic(message)
+}

result/result_test.go

@@ -79,6 +79,12 @@ func ExampleResult_UnwrapErr() {
 	// Output: oops
 }
 
+func ExampleResult_Expect() {
+	fmt.Println(result.Ok(4).Expect("oops"))
+
+	// Output: 4
+}
+
 func TestOkStringer(t *testing.T) {
 	assert.Equal(t, fmt.Sprintf("%s", result.Ok(42)), "Ok(42)") //nolint:gosimple
 }
@@ -160,3 +166,16 @@ func TestOkUnwrapErr(t *testing.T) {
 	_ = result.Ok(42).UnwrapErr()
 	t.Error("did not panic")
 }
+
+func TestOkExpect(t *testing.T) {
+	assert.Equal(t, result.Ok(42).Expect("oops"), 42)
+}
+
+func TestErrExpect(t *testing.T) {
+	defer func() {
+		assert.Equal(t, fmt.Sprintf("%v", recover()), "oops")
+	}()
+
+	_ = result.Err[int](errors.New("oops")).Expect("oops")
+	t.Error("did not panic")
+}