Add fourmolu fixer (#4501)

* Add fourmolu fixer

Fourmolu is aversion of Ormolu that supports configuration. This fixer
was modeled after the Ormolu one, but using the "stack executable"
approach of the Brittany and Stylish Haskell fixers.

* Sort supported-tools.md

1 files changed, 29 insertions, 0 deletions

diff --git a/test/fixers/test_fourmolu_fixer_callback.vader b/test/fixers/test_fourmolu_fixer_callback.vader
new file mode 100644
index 00000000..728c02ed
--- /dev/null
+++ b/test/fixers/test_fourmolu_fixer_callback.vader
@@ -0,0 +1,29 @@
+Before:
+  Save g:ale_haskell_fourmolu_executable
+  Save g:ale_haskell_fourmolu_options
+
+After:
+  Restore
+
+Execute(The fourmolu callback should return the correct default values):
+  AssertEqual
+  \ {
+  \   'command': ale#Escape('fourmolu')
+  \     . ' --stdin-input-file '
+  \     . ale#Escape(@%)
+  \ },
+  \ ale#fixers#fourmolu#Fix(bufnr(''))
+
+Execute(The fourmolu executable and options should be configurable):
+  let g:ale_haskell_fourmolu_executable = '/path/to/fourmolu'
+  let g:ale_haskell_fourmolu_options = '-h'
+
+  AssertEqual
+  \ {
+  \   'command': ale#Escape('/path/to/fourmolu')
+  \     . ' -h'
+  \     . ' --stdin-input-file '
+  \     . ale#Escape(@%)
+  \ },
+  \ ale#fixers#fourmolu#Fix(bufnr(''))
+