how to configure ghcid with hspec

README.md

@@ -58,6 +58,63 @@ After modifying code use:
 **Note:** `:reload` will be much faster than loading the code initially.  This
 makes a big difference for larger projects.
 
+
+### With `ghcid`
+
+[ghcid](https://github.com/ndmitchell/ghcid) is a wrapper around `ghci` that
+automatically issues a `:reload` to `ghci` whenever you save your source files.
+You can configure `ghcid` to automatically run the tests on a successful build.
+With the right editor integration this makes for a fast and convenient
+edit-compile-test cycle.
+
+With the right setup, `ghcid` allows you to automatically recompile your
+project on save, source any compile errors into your editor, update your tags
+file, and run the tests. All this with the speed of `ghci :reload`.
+
+To install ghcid, use stack:
+
+```
+$ stack install ghcid
+```
+
+`ghcid` requires you to set up `ghci` so that a `:reload` reloads all your
+source files. This is your responsibility. Any `ghci` will do, here we describe
+how to set it up with `stack ghci`.
+
+The default project layout you get from `stack new` consists of three
+components: a library, a main executable, and a test suite. Ideally, you would
+want to `:reload` all three, but it is not possible to have both the test suite
+and the main executable loaded in `ghci` at the same time. The workaround we
+suggest is to move all code from the main executable to the library, into a
+`Run.hs` module. This way `ghci` only has to `:reload` the library and the test
+suite, which works nicely.
+
+Once you have set up your stack project `your-project` like this, create a file
+`.ghcid` in your project directory with the following contents, and then run
+`ghcid`.
+
+```
+$ cat .ghcid
+--command=stack ghci your-project:your-project-test your-project:lib --test=main
+```
+
+As added bonus, `ghcid` can write the compiler output to a file. If you use vim
+for example, make the file `errors.err`, have a correct error format, and you
+can `:cfile` compiler errors.
+
+As another added bonus, `ghcid` can call an external program on successful
+build. The flag for this is called `--lint`, but you can use any program you
+want. For example, you can update your tags file on each successful build. The
+shell script `make-tags-haskell.sh` here is a wrapper around `hasktags -c .`
+
+```
+$ cat .ghcid
+--command=stack ghci your-project:your-project-test your-project:lib --outputfile=errors.err --lint=make-tags-haskell.sh --test=main
+```
+
+
+
+
 ## With `sensei`
 
 Using [hspec/sensei](https://github.com/hspec/sensei) is similar to using