Support CTest

[jimmy-park]

I added test/CMakeLists.txt because the current testing workflow is separate from the CMake build system.
Now we can do this for testing in a cross-platform way.

cmake -S . -B build -DHTTPLIB_TEST=ON
cmake --build build && cd build
ctest

I also tested httplib with OpenSSL as shown in test/Makefile.
This requires me to generate some cert files in the build directory.
Here is results on my machine (Windows 10)

It may test with Brotli and zlib as well if libraries are installed correctly.

[jimmy-park]

Testing with OpenSSL, Brotli and zlib was successful in my VM (Ubuntu 22.04).
But it needed to install following libraries.

sudo apt install -y libssl-dev libbrotli-dev zlib1g-dev

[jimmy-park]

For some reason, generating cert2.pem only fails on macOS unless we add the -new option.
1a41e71 will fix this issue.

PS. tests in CI sometimes fail due to network issues.

[yhirose]

@jimmy-park, thanks for the pull request. I found some embedded strings, 1) physical paths such as www, www2..., 2) version number like https://github.com/google/googletest/archive/release-1.12.1.tar.gz. These my cause problems eventually and need to be taken care of. Please see more information in #955, #1033, #1044.

I actually don't maintain any CMake related files. @sum01 kindly takes care of those files, so that I don't need to worry about it. Could you willingly take a responsibility to maintain test/CMakeLists.txt whenever problems happen with it in the future? If so, I'll accept this pull request. Please see my policy about CMake and Meson in the following comment.
#955 (comment)

Thanks for your understanding!

[jimmy-park]

@yhirose Thanks for replying.

1. physical paths such as www, www2...

Since test.cc requires some files where it located in and httplib-test will be executed in CMAKE_CURRENT_BINARY_DIR, I needed to copy these files from the test directory to the CMAKE_CURRENT_BINARY_DIR. Cert files are created the same way.

2. version number like https://github.com/google/googletest/archive/release-1.12.1.tar.gz

We can choose the latest main branch using https://github.com/google/googletest/archive/main.tar.gz. It seems like Google also recommends this way. Is it okay with this library?

I saw comments and understand what you are concerned about. I'm willing to maintain test/CMakeLists.txt and update it when test/Makefile changes.

Thanks for the useful library 😄

[yhirose]

@jimmy-park thanks for the answers, and accept maintaining it! As you mentioned, could you try to use Google Test from the latest main branch?

[jimmy-park]

@yhirose Sure!

[yhirose]

@jimmy-park, thanks for the fine contribution!

[Tachi107]

Sorry for my late review, but I wasn't notified about this patch until the 0.12.0 release.

Mostly minor issues/suggestions

[yhirose]

@jimmy-park could you replay to @Tachi107's comments and suggestions?

[jimmy-park]

@Tachi107 Thanks for suggestions. I commented my thoughts and some possible modifications.

@yhirose I think applying @Tachi107's suggestion is required. However, since this pull request had been merged, I will open a new pull request after resolving these conversations.

[yhirose]

@jimmy-park yes, please go ahead to make another pull request for the adjustments. Thanks!