hhvm composer require hhvm/hhast
vendor/bin/hhast-lint src/
This will run a default set of linters against your source tree. If you do not have a configuration file, paths must be specified on the command line.
An hhast-lint.json in your project root can be used to modify which linters are used, or to otherwise customize the behavior. A minimal configuration would be:
{
"roots": [ "src/" ]
}
This would configure hhast-lint with no arguments check src/ with otherwise-default settings. For information on additional options, see LinterCLIConfig::TConfigFile.
Options can also be overriden for specific file patterns or subdirectories - for example, HHAST itself disables autofixes for codegen/.