You can make a command run when certain files change by prefixing the
command with ~. Monitoring is terminated when enter is pressed. This
triggered execution is configured by the watch setting, but typically
the basic settings watchSources and pollInterval are modified.
watchSources defines the files for a single project that are
monitored for changes. By default, a project watches resources and
Scala and Java sources.
watchTransitiveSources then combines the watchSources for the
current project and all execution and classpath dependencies (see
.scala build definition for details on
interProject dependencies).
pollInterval selects the interval between polling for changes in
milliseconds. The default value is 500 ms.
Some example usages are described below.
The original use-case was continuous compilation:
> ~ test:compile
> ~ compile
You can use the triggered execution feature to run any command or task. One use is for test driven development, as suggested by Erick on the mailing list.
The following will poll for changes to your source code (main or test)
and run testOnly for the specified test.
> ~ testOnly example.TestA
Occasionally, you may need to trigger the execution of multiple commands. You can use semicolons to separate the commands to be triggered.
The following will poll for source changes and run clean and test.
> ~ ;clean ;test
