Add method to remove property

Fixes #95

components.go

@@ -89,6 +89,18 @@ func (cb *ComponentBase) AddProperty(property ComponentProperty, value string, p
 	cb.Properties = append(cb.Properties, r)
 }
 
+// RemoveProperty removes from the component all properties that has
+// the name passed in removeProp.
+func (cb *ComponentBase) RemoveProperty(removeProp ComponentProperty) {
+	var keptProperties []IANAProperty
+	for i := range cb.Properties {
+		if cb.Properties[i].IANAToken != string(removeProp) {
+			keptProperties = append(keptProperties, cb.Properties[i])
+		}
+	}
+	cb.Properties = keptProperties
+}
+
 const (
 	icalTimestampFormatUtc   = "20060102T150405Z"
 	icalTimestampFormatLocal = "20060102T150405"

components_test.go

@@ -132,3 +132,34 @@ func TestSetMailtoPrefix(t *testing.T) {
 		t.Errorf("expected single mailto: prefix for email att2")
 	}
 }
+
+func TestRemoveProperty(t *testing.T) {
+	testCases := []struct {
+		name   string
+		output string
+	}{
+		{
+			name: "test RemoveProperty - start",
+			output: `BEGIN:VTODO
+UID:test-removeproperty
+X-TEST:42
+END:VTODO
+`,
+		},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			e := NewTodo("test-removeproperty")
+			e.AddProperty("X-TEST", "42")
+			e.AddProperty("X-TESTREMOVE", "FOO")
+			e.AddProperty("X-TESTREMOVE", "BAR")
+			e.RemoveProperty("X-TESTREMOVE")
+
+			// adjust to expected linebreaks, since we're not testing the encoding
+			text := strings.Replace(e.Serialize(), "\r\n", "\n", -1)
+
+			assert.Equal(t, tc.output, text)
+		})
+	}
+}