Add Apple's swift-format as a linter

1 files changed, 62 insertions, 0 deletions

diff --git a/ale_linters/swift/swiftformat.vim b/ale_linters/swift/swiftformat.vim
new file mode 100644
index 00000000..2504511a
--- /dev/null
+++ b/ale_linters/swift/swiftformat.vim
@@ -0,0 +1,62 @@
+" Author: Klaas Pieter Annema <https://github.com/klaaspieter>
+" Description: Support for swift-format https://github.com/apple/swift-format
+
+let s:default_executable = 'swift-format'
+call ale#Set('swift_swiftformat_executable', s:default_executable)
+
+function! ale_linters#swift#swiftformat#UseSwift(buffer) abort
+    let l:swift_config = ale#path#FindNearestFile(a:buffer, 'Package.swift')
+    let l:executable = ale#Var(a:buffer, 'swift_swiftformat_executable')
+
+    return !empty(l:swift_config) && l:executable is# s:default_executable
+endfunction
+
+function! ale_linters#swift#swiftformat#GetExecutable(buffer) abort
+    if ale_linters#swift#swiftformat#UseSwift(a:buffer)
+        return 'swift'
+    endif
+
+    return ale#Var(a:buffer, 'swift_swiftformat_executable')
+endfunction
+
+function! ale_linters#swift#swiftformat#GetCommand(buffer) abort
+    let l:executable = ale_linters#swift#swiftformat#GetExecutable(a:buffer)
+    let l:args = '--mode lint %t'
+
+    if ale_linters#swift#swiftformat#UseSwift(a:buffer)
+        let l:args = 'run swift-format' . ' ' . l:args
+    endif
+
+    return ale#Escape(l:executable) . ' ' . l:args
+endfunction
+
+function! ale_linters#swift#swiftformat#Handle(buffer, lines) abort
+    " Matches lines of the following pattern:
+    "
+    " Sources/main.swift:4:21: warning: [DoNotUseSemicolons]: remove ';' and move the next statement to the new line
+    " Sources/main.swift:3:12: warning: [Spacing]: remove 1 space
+    let l:pattern = '\v^.*:(\d+):(\d+): (\S+) \[(\S+)\]: (.*)$'
+    let l:output = []
+
+    for l:match in ale#util#GetMatches(a:lines, l:pattern)
+        call add(l:output, {
+        \   'lnum': l:match[1] + 0,
+        \   'col': l:match[2] + 0,
+        \   'type': l:match[3] is# 'error' ? 'E' : 'W',
+        \   'code': l:match[4],
+        \   'text': l:match[5],
+        \})
+    endfor
+
+    return l:output
+endfunction
+
+
+call ale#linter#Define('swift', {
+\   'name': 'swift-format',
+\   'executable': function('ale_linters#swift#swiftformat#GetExecutable'),
+\   'command': function('ale_linters#swift#swiftformat#GetCommand'),
+\   'output_stream': 'stderr',
+\   'language': 'swift',
+\   'callback': 'ale_linters#swift#swiftformat#Handle'
+\})