mirror of
https://github.com/catchorg/Catch2.git
synced 2024-11-04 21:29:54 +01:00
126 lines
3.9 KiB
Markdown
126 lines
3.9 KiB
Markdown
<a id="top"></a>
|
|
# Supplying main() yourself
|
|
|
|
The easiest way to use Catch is to let it supply ```main()``` for you and handle configuring itself from the command line.
|
|
|
|
This is achieved by writing ```#define CATCH_CONFIG_MAIN``` before the ```#include "catch.hpp"``` in *exactly one* source file.
|
|
|
|
Sometimes, though, you need to write your own version of main(). You can do this by writing ```#define CATCH_CONFIG_RUNNER``` instead. Now you are free to write ```main()``` as normal and call into Catch yourself manually.
|
|
|
|
You now have a lot of flexibility - but here are three recipes to get your started:
|
|
|
|
## Let Catch take full control of args and config
|
|
|
|
If you just need to have code that executes before and/ or after Catch this is the simplest option.
|
|
|
|
```c++
|
|
#define CATCH_CONFIG_RUNNER
|
|
#include "catch.hpp"
|
|
|
|
int main( int argc, char* argv[] ) {
|
|
// global setup...
|
|
|
|
int result = Catch::Session().run( argc, argv );
|
|
|
|
// global clean-up...
|
|
|
|
return result;
|
|
}
|
|
```
|
|
|
|
## Amending the config
|
|
|
|
If you still want Catch to process the command line, but you want to programmatically tweak the config, you can do so in one of two ways:
|
|
|
|
```c++
|
|
#define CATCH_CONFIG_RUNNER
|
|
#include "catch.hpp"
|
|
|
|
int main( int argc, char* argv[] )
|
|
{
|
|
Catch::Session session; // There must be exactly one instance
|
|
|
|
// writing to session.configData() here sets defaults
|
|
// this is the preferred way to set them
|
|
|
|
int returnCode = session.applyCommandLine( argc, argv );
|
|
if( returnCode != 0 ) // Indicates a command line error
|
|
return returnCode;
|
|
|
|
// writing to session.configData() or session.Config() here
|
|
// overrides command line args
|
|
// only do this if you know you need to
|
|
|
|
int numFailed = session.run();
|
|
|
|
// numFailed is clamped to 255 as some unices only use the lower 8 bits.
|
|
// This clamping has already been applied, so just return it here
|
|
// You can also do any post run clean-up here
|
|
return numFailed;
|
|
}
|
|
```
|
|
|
|
Take a look at the definitions of Config and ConfigData to see what you can do with them.
|
|
|
|
To take full control of the config simply omit the call to ```applyCommandLine()```.
|
|
|
|
## Adding your own command line options
|
|
|
|
Catch embeds a powerful command line parser called [Clara](https://github.com/philsquared/Clara).
|
|
As of Catch2 (and Clara 1.0) Clara allows you to write _composable_ option and argument parsers,
|
|
so extending Catch's own command line options is now easy.
|
|
|
|
```c++
|
|
#define CATCH_CONFIG_RUNNER
|
|
#include "catch.hpp"
|
|
|
|
int main( int argc, char* argv[] )
|
|
{
|
|
Catch::Session session; // There must be exactly one instance
|
|
|
|
int height = 0; // Some user variable you want to be able to set
|
|
|
|
// Build a new parser on top of Catch's
|
|
using namespace Catch::clara;
|
|
auto cli
|
|
= session.cli() // Get Catch's composite command line parser
|
|
| Opt( height, "height" ) // bind variable to a new option, with a hint string
|
|
["-g"]["--height"] // the option names it will respond to
|
|
("how high?"); // description string for the help output
|
|
|
|
// Now pass the new composite back to Catch so it uses that
|
|
session.cli( cli );
|
|
|
|
// Let Catch (using Clara) parse the command line
|
|
int returnCode = session.applyCommandLine( argc, argv );
|
|
if( returnCode != 0 ) // Indicates a command line error
|
|
return returnCode;
|
|
|
|
// if set on the command line then 'height' is now set at this point
|
|
if( height > 0 )
|
|
std::cout << "height: " << height << std::endl;
|
|
|
|
return session.run();
|
|
}
|
|
```
|
|
|
|
See the [Clara documentation](https://github.com/philsquared/Clara/blob/master/README.md) for more details.
|
|
|
|
|
|
## Version detection
|
|
|
|
Catch provides a triplet of macros providing the header's version,
|
|
|
|
* `CATCH_VERSION_MAJOR`
|
|
* `CATCH_VERSION_MINOR`
|
|
* `CATCH_VERSION_PATCH`
|
|
|
|
these macros expand into a single number, that corresponds to the appropriate
|
|
part of the version. As an example, given single header version v2.3.4,
|
|
the macros would expand into `2`, `3`, and `4` respectively.
|
|
|
|
|
|
---
|
|
|
|
[Home](Readme.md#top)
|