dont_reuse_prop: {
    mangle = {
        properties: {
            domprops: true,
            regex: /asd/,
        },
    }
    input: {
        "aaaaaaaaaabbbbb";
        var obj = {};
        obj.a = 123;
        obj.asd = 256;
        console.log(obj.a);
    }
    expect: {
        "aaaaaaaaaabbbbb";
        var obj = {};
        obj.a = 123;
        obj.b = 256;
        console.log(obj.a);
    }
    expect_stdout: "123"
    expect_warnings: [
        "INFO: Preserving excluded property a",
        "INFO: Mapping property asd to b",
        "INFO: Preserving reserved property log",
    ]
}

unmangleable_props_should_always_be_reserved: {
    mangle = {
        properties: {
            domprops: true,
            regex: /asd/,
        },
    }
    input: {
        "aaaaaaaaaabbbbb";
        var obj = {};
        obj.asd = 256;
        obj.a = 123;
        console.log(obj.a);
    }
    expect: {
        "aaaaaaaaaabbbbb";
        var obj = {};
        obj.b = 256;
        obj.a = 123;
        console.log(obj.a);
    }
    expect_stdout: "123"
    expect_warnings: [
        "INFO: Preserving excluded property a",
        "INFO: Mapping property asd to b",
        "INFO: Preserving reserved property log",
    ]
}