Matthew Lugg
4f7344dec0
Unions with no fields are now "uninstantiable" types, which work like `noreturn` in that values of this type cannot exist. Enums with no fields are different because they are currently considered `extern` types, though https://github.com/ziglang/zig/issues/19855 will change this in the future.
Test Case Quick Reference
Use comments at the end of the file to indicate metadata about the test case. Here are examples of different kinds of tests:
Compile Error Test
If you want it to be run with zig test and match expected error messages:
// error
// is_test=true
//
// :4:13: error: 'try' outside function scope
Execution
This will do zig run on the code and expect exit code 0.
// run
Incremental Compilation
Make multiple files that have ".", and then an integer, before the ".zig" extension, like this:
hello.0.zig
hello.1.zig
hello.2.zig
Each file can be a different kind of test, such as expecting compile errors, or expecting to be run and exit(0). The test harness will use these to simulate incremental compilation.
At the time of writing there is no way to specify multiple files being changed as part of an update.
Subdirectories
Subdirectories do not have any semantic meaning but they can be used for organization since the test harness will recurse into them. The full directory path will be prepended as a prefix on the test case name.
Limiting which Backends and Targets are Tested
// run
// backend=selfhosted,llvm
// target=x86_64-linux,x86_64-macos
Possible backends are:
auto: the default; compiler picks the backend based on robustness.selfhosted: equivalent to passing-fno-llvm -fno-lld.llvm: equivalent to-fllvm.