feat(terraform): add snyk linter for terraform

ale_linters/terraform/snyk.vim

@@ -0,0 +1,61 @@
+" Description: snyk for Terraform files
+"
+" See: https://www.terraform.io/
+"      https://github.com/snyk/cli
+
+call ale#Set('terraform_snyk_options', '')
+call ale#Set('terraform_snyk_executable', 'snyk')
+
+let s:separator = has('win32') ? '\' : '/'
+
+function! ale_linters#terraform#snyk#Handle(buffer, lines) abort
+    let l:output = []
+    let l:json = ale#util#FuzzyJSONDecode(a:lines, {})
+
+    for l:result in l:json
+        if l:result.ok is# v:false
+            for l:iac_issues in get(l:result, 'infrastructureAsCodeIssues')
+                if l:iac_issues.severity is# 'low' || l:iac_issues.severity is# 'medium'
+                    let l:type = 'W'
+                elseif l:iac_issues.severity is# 'high' || l:iac_issues.severity is# 'critical'
+                    let l:type = 'E'
+                else
+                    let l:type = 'W'
+                endif
+
+                call add(l:output, {
+                \   'filename': l:result.targetFilePath,
+                \   'lnum': l:iac_issues.lineNumber,
+                \   'text': l:iac_issues.iacDescription.issue,
+                \   'code': l:iac_issues.publicId,
+                \   'type': l:type,
+                \})
+            endfor
+        endif
+    endfor
+
+    return l:output
+endfunction
+
+" Construct command arguments to snyk with `terraform_snyk_options`.
+function! ale_linters#terraform#snyk#GetCommand(buffer) abort
+    let l:cmd = '%e iac test'
+
+    let l:opts = ale#Var(a:buffer, 'terraform_snyk_options')
+
+    if !empty(l:opts)
+        let l:cmd .= ale#Pad(l:opts)
+    endif
+
+    let l:cmd .= ale#Pad('--json')
+
+    return l:cmd
+endfunction
+
+call ale#linter#Define('terraform', {
+\   'name': 'snyk',
+\   'executable': {b -> ale#Var(b, 'terraform_snyk_executable')},
+\   'cwd': '%s:h',
+\   'command': function('ale_linters#terraform#snyk#GetCommand'),
+\   'callback': 'ale_linters#terraform#snyk#Handle',
+\})