def "serializes empty directives"() {
        def directives = DefaultIncludeDirectives.of(ImmutableList.of(), ImmutableList.of(), ImmutableList.of())

        expect:
        serialize(directives, IncludeDirectivesSerializer.INSTANCE) == directives
    }

    def "serializes include directives"() {
        def include1 = new IncludeWithSimpleExpression("one.h", true, IncludeType.QUOTED)

            @Override
            public IncludeDirectives calculate(File file, boolean isRegularFile) {
                return parser.parseSource(file);
            }
        }, IncludeDirectivesSerializer.INSTANCE);
    }

    @Override
    public IncludeDirectives parseSource(File sourceFile) {
        return cache.get(sourceFile);
    }