[serialization][test] Helping end-user testing serialisation
Hello everybody, I think I have some idea that might improve the ease for the end user to test if he properly set-up his class for serialization. Sorry if this idea has already been discussed (or even is already implemented), but I tried to search a little, without finding anything about this. The main idea is that if an user has a serializable class, he will probably want to test wether he forgot to put some usefull member data in his |serialize function. Thus, he will have to write some test with always the same pattern. My suggestion is to put test_tools.hpp inside the serialization library, along with some template :| || |template<class T> void check_serialization(T const &t) // t should not be initialized to default values| |{| | const char * testfile = boost::archive::tmpnam(NULL);| | BOOST_REQUIRE(NULL != testfile);| | {| || std::ofstream ofs(testFile); | boost::archive::text_oarchive oa(ofs);| | oa|| << t;| | }| | { ||| T t1; || std::ifstream ifs(testFile, std::ios::binary); | boost::archive::text_iarchive ia(ifs); | ia >> t1 ||| }| | BOOST_CHECK_EQUAL(t, t1);| | std::remove(testfile);| |||}| |||| Do you think it would make a worthy addition ? -- Loïc | |
Loïc Joly <loic.actarus.joly@wanadoo.fr> writes:
Do you think it would make a worthy addition ?
How about adding concept checking to Boost.Serialization? The Boost Concept Checking library is awesome for finding problems like that. -- Dave Abrahams Boost Consulting www.boost-consulting.com
I think the problem addressed by the original post is not addressable by concept checking. It really address the problem where by one can make a mistake in getting save and load out of sync. This can occur in more complicated situatons where serialize has to be split in to load and save and there are things like versioning involved. I'm not sure this idea would be that much help. I would love an automatic test generation program and indeed many of the test programs are similar. The problem I have is that generating the test data is problematic and in general can't be done automatically. So at this point, I would expect that incorporating this idea would be more trouble that the benefit rendered. Also, take note of the xml_archive.hpp as it regards testing serialization. I personally have no use for the xml archive. Well, now that I have it I do use it. It has a couple of valuable attributes. a) Its readable and so all the extra data in a serialized data file is labled, eg class id, object reference, name of the data field, etc. b) On loading, the <name> ... </name> tags are checked to see that they match. In fact, if the save and load are out of sync, the load will most likely trap with an exception at the point where the mismatch exists. So if you're looking for a problem in your serialization specifications, use an xml_archive in your test! Do this even if - or especially if - you're not otherwise using XML. As for concept checking. I'm very interested in this. When I started the serialization library, I didn't really understand enough of C++ templates to appreciate this. I really didn't know about how to document a library based on overloading. etc. I looked at the Concept Checking Library and without knowing these other things it wasn't really clear how to use it. Now, after much more experience with C++, templates etc. I see how useful this could be. To get maximum utility from it, one really needs to make the documentation in a more formal way. Based on the informaton on the SGI website. I've been making small steps in this direction but its a way to go. If I knew when I started what I know now. Things would have been different. a) I probrably would have started the same. Experimenting with limited set of simple use cases. b) When I thought I was ready to deliver something I would make a tutorial. That would be the same. c) I would have made a more formal reference document and included Concept Checking in the code. From then on these could be kept in sync. (more or less). d) I would try to make the test cases to double check the concept checking I don't think this would have been all that much more work (if any) than the more ad hoc way I went about it. But- a major part of getting a boost library working is making it function on a wide variety of compilers. Some compilers already scream under the strain of compiling the serialization library. I wonder how concept checking would affect this. I was at the book store the other day in the computer section, and was struck by the wide array of titles and the lack of selection. In short, I think the world needs a new C++ book. "How to write a fast, correct, program in C++" which would presume a working knowledge of C++. Topics 1) Why templates matter 2) Hto write formal specifications for templates 3) Concept checking 4) Program testing This might be part of another book "Leveraged Software Development using Boost Libraries" 1) Simple Application 1 - how boost libraries make it trivial 2) Applicaiton 2 - how .... 3) Using templates and boost to implement an application architecture - case study Model View Contoller. Anyway its fun to speculate. Robert Ramey David Abrahams wrote:
Loïc Joly <loic.actarus.joly@wanadoo.fr> writes:
Do you think it would make a worthy addition ?
How about adding concept checking to Boost.Serialization? The Boost Concept Checking library is awesome for finding problems like that.
participants (3)
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David Abrahams -
Loïc Joly -
Robert Ramey