Fix 2726 - fix terraform linter.

Instead of using `terraform fmt` for linting use `terraform validate`
with json output.

ale_linters/terraform/terraform.vim

@@ -9,30 +9,40 @@ endfunction
 
 function! ale_linters#terraform#terraform#GetCommand(buffer) abort
     return ale#Escape(ale_linters#terraform#terraform#GetExecutable(a:buffer))
-    \   . ' fmt -no-color --check=true -'
+    \   . ' validate -no-color -json '
+endfunction
+
+function! ale_linters#terraform#terraform#GetType(severity) abort
+    if a:severity is? 'warning'
+        return 'W'
+    endif
+
+    return 'E'
 endfunction
 
 function! ale_linters#terraform#terraform#Handle(buffer, lines) abort
-    let l:head = '^Error running fmt: In <standard input>: '
     let l:output = []
-    let l:patterns = [
-    \   l:head.'At \(\d\+\):\(\d\+\): \(.*\)$',
-    \   l:head.'\(.*\)$'
-    \]
 
-    for l:match in ale#util#GetMatches(a:lines, l:patterns)
-        if len(l:match[2]) > 0
+    let l:errors = ale#util#FuzzyJSONDecode(a:lines, {'diagnostics': []})
+    let l:dir = expand('#' . a:buffer . ':p:h')
+    let l:file = expand('#' . a:buffer . ':p')
+
+    for l:error in l:errors['diagnostics']
+        if has_key(l:error, 'range')
             call add(l:output, {
-            \   'lnum': str2nr(l:match[1]),
-            \   'col': str2nr(l:match[2]),
-            \   'text': l:match[3],
-            \   'type': 'E',
+            \   'filename': ale#path#GetAbsPath(l:dir, l:error['range']['filename']),
+            \   'lnum': l:error['range']['start']['line'],
+            \   'col': l:error['range']['start']['column'],
+            \   'text': l:error['detail'],
+            \   'type': ale_linters#terraform#terraform#GetType(l:error['severity']),
             \})
         else
             call add(l:output, {
-            \   'lnum': line('$'),
-            \   'text': l:match[1],
-            \   'type': 'E',
+            \   'filename': l:file,
+            \   'lnum': 0,
+            \   'col': 0,
+            \   'text': l:error['detail'],
+            \   'type': ale_linters#terraform#terraform#GetType(l:error['severity']),
             \})
         endif
     endfor
@@ -42,7 +52,7 @@ endfunction
 
 call ale#linter#Define('terraform', {
 \   'name': 'terraform',
-\   'output_stream': 'stderr',
+\   'output_stream': 'stdout',
 \   'executable': function('ale_linters#terraform#terraform#GetExecutable'),
 \   'command': function('ale_linters#terraform#terraform#GetCommand'),
 \   'callback': 'ale_linters#terraform#terraform#Handle',

test/command_callback/test_terraform_terraform_command_callback.vader

@@ -6,4 +6,10 @@ After:
   call ale#assert#TearDownLinterTest()
 
 Execute(The default command should be correct):
-  AssertLinter 'terraform', ale#Escape('terraform') . ' fmt -no-color --check=true -'
+  AssertLinter 'terraform',
+  \ ale#Escape('terraform') . ' validate -no-color -json '
+
+Execute(The default command should be overriden):
+  let b:ale_terraform_terraform_executable = '/bin/other/terraform'
+  AssertLinter '/bin/other/terraform',
+  \ ale#Escape('/bin/other/terraform') . ' validate -no-color -json '

test/handler/test_terraform_handler.vader

@@ -1,34 +1,61 @@
 Before:
   " Load the file which defines the linter.
   runtime ale_linters/terraform/terraform.vim
+  call ale#test#SetDirectory('/testplugin/test/terraform_files')
+  call ale#test#SetFilename('providers.tf')
 
 After:
   " Unload all linters again.
   call ale#linter#Reset()
+  call ale#test#RestoreDirectory()
 
 Execute(The output should be correct):
   AssertEqual
   \ [
   \   {
-  \     'lnum': 1,
-  \     'col': 20,
-  \     'type': 'E',
-  \     'text': 'illegal char',
+  \     'lnum': 17,
+  \     'col': 13,
+  \     'filename': '/testplugin/test/terraform_files/providers.tf',
+  \     'type': 'W',
+  \     'text': 'Terraform 0.13 and earlier allowed provider version',
   \   },
   \   {
-  \     'lnum': 2,
-  \     'col': 14,
+  \     'lnum': 0,
+  \     'col': 0,
+  \     'filename': '/testplugin/test/terraform_files/providers.tf',
   \     'type': 'E',
-  \     'text': 'literal not terminated',
-  \   },
-  \   {
-  \     'lnum': 1,
-  \     'type': 'E',
-  \     'text': 'object expected closing RBRACE got: EOF',
-  \   },
+  \     'text': 'Plugin reinitialization required. Please run "terraform"',
+  \   }
   \ ],
   \ ale_linters#terraform#terraform#Handle(bufnr(''), [
-  \ 'Error running fmt: In <standard input>: At 1:20: illegal char',
-  \ 'Error running fmt: In <standard input>: At 2:14: literal not terminated',
-  \ 'Error running fmt: In <standard input>: object expected closing RBRACE got: EOF',
+  \ '{',
+  \ '"valid": false,',
+  \ '"error_count": 1,',
+  \ '"warning_count": 1,',
+  \ '"diagnostics": [',
+  \ '  {',
+  \ '    "severity": "warning",',
+  \ '    "summary": "Version constraints inside provider configuration blocks are deprecated",',
+  \ '    "detail": "Terraform 0.13 and earlier allowed provider version",',
+  \ '    "range": {',
+  \ '      "filename": "providers.tf",',
+  \ '      "start": {',
+  \ '        "line": 17,',
+  \ '        "column": 13,',
+  \ '        "byte": 669',
+  \ '      },',
+  \ '      "end": {',
+  \ '        "line": 17,',
+  \ '        "column": 24,',
+  \ '        "byte": 680',
+  \ '      }',
+  \ '    }',
+  \ '  },',
+  \ '  {',
+  \ '    "severity": "error",',
+  \ '    "summary": "Could not load plugin",',
+  \ '    "detail": "Plugin reinitialization required. Please run \"terraform\""',
+  \ '  }',
+  \ '  ]',
+  \ '}',
   \ ])