more tests

map.go

@@ -39,7 +39,7 @@ package opt
 //	
 //	// result2 == opt.Nothing[int]()
 func Map[T1 any, T2 any](op Optional[T1], fn func(T1)T2) Optional[T2] {
-	if !op.something {
+	if op.isnothing() {
 		return Nothing[T2]()
 	}
 

optional.go

@@ -107,7 +107,7 @@ func Something[T any](value T) Optional[T] {
 //	
 //	op3 = op3.Filter(fn)
 func (receiver Optional[T]) Filter(fn func(T)bool) Optional[T] {
-	if !receiver.something {
+	if receiver.isnothing() {
 		return Nothing[T]()
 	}
 
@@ -118,6 +118,10 @@ func (receiver Optional[T]) Filter(fn func(T)bool) Optional[T] {
 	return receiver
 }
 
+func (receiver Optional[T]) isnothing() bool {
+	return !receiver.something
+}
+
 // Get returns the value inside of the optional-type if it is holding something.
 //
 // Example usage:
@@ -162,7 +166,7 @@ func (receiver Optional[T]) Get() (T, bool) {
 //	// Output:
 //	// op = opt.Nothing[uint8]()
 func (receiver Optional[T]) GoString() string {
-	if !receiver.something {
+	if receiver.isnothing() {
 		return fmt.Sprintf("opt.Nothing[%T]()", receiver.value)
 	}
 
@@ -183,7 +187,7 @@ func (receiver Optional[T]) GoString() string {
 //		//@TODO
 //	})
 func (receiver Optional[T]) WhenNothing(fn func()) {
-	if !receiver.something {
+	if receiver.isnothing() {
 		fn()
 	}
 }

optional_marshaljson_bool_test.go

@@ -44,3 +44,22 @@ func TestOptional_MarshalJSON_bool(t *testing.T) {
 		}
 	}
 }
+
+func TestOptional_MarshalJSON_bool_fail(t *testing.T) {
+
+	var nothing opt.Optional[bool]
+
+	actualBytes, err := nothing.MarshalJSON()
+	if nil == err {
+		t.Error("Expected an error but did not actually get one.")
+		t.Logf("ACTUAL: %q", actualBytes)
+		t.Logf("ERROR: (%T) %s", err, err)
+		return
+	}
+	if nil != actualBytes {
+		t.Error("Expected not bytes but actually get some.")
+		t.Logf("ACTUAL: %q", actualBytes)
+		t.Logf("ERROR: (%T) %s", err, err)
+		return
+	}
+}

optional_marshaljson_string_test.go

@@ -103,3 +103,22 @@ func TestOptional_MarshalJSON_string(t *testing.T) {
 		}
 	}
 }
+
+func TestOptional_MarshalJSON_string_fail(t *testing.T) {
+
+	var nothing opt.Optional[string]
+
+	actualBytes, err := nothing.MarshalJSON()
+	if nil == err {
+		t.Error("Expected an error but did not actually get one.")
+		t.Logf("ACTUAL: %q", actualBytes)
+		t.Logf("ERROR: (%T) %s", err, err)
+		return
+	}
+	if nil != actualBytes {
+		t.Error("Expected not bytes but actually get some.")
+		t.Logf("ACTUAL: %q", actualBytes)
+		t.Logf("ERROR: (%T) %s", err, err)
+		return
+	}
+}

then.go

@@ -36,7 +36,7 @@ package opt
 //	
 //	// result2 == opt.Nothing[byte]()
 func Then[T1 any, T2 any](op Optional[T1], fn func(T1)Optional[T2]) Optional[T2] {
-	if !op.something {
+	if op.isnothing() {
 		return Nothing[T2]()
 	}