Fallback to summary field if detail exists but is empty in terraform linter (#4157)

* Fallback to summary field if detail exists but is empty in terraform linter

* Add test

* Update terraform.vim

* remove whitespaces

ale_linters/terraform/terraform.vim

@@ -21,7 +21,13 @@ function! ale_linters#terraform#terraform#GetType(severity) abort
 endfunction
 
 function! ale_linters#terraform#terraform#GetDetail(error) abort
-    return get(a:error, 'detail', get(a:error, 'summary', ''))
+    let l:detail = get(a:error, 'detail', '')
+
+    if strlen(l:detail) > 0
+        return l:detail
+    else
+        return get(a:error, 'summary', '')
+    endif
 endfunction
 
 function! ale_linters#terraform#terraform#Handle(buffer, lines) abort

test/handler/test_terraform_handler.vader

@@ -97,3 +97,42 @@ Execute(Should use summary if detail not available):
   \ '  ]',
   \ '}'
   \ ])
+
+Execute(Should use summary if detail available but empty):
+  AssertEqual
+  \ [
+  \   {
+  \     'lnum': 91,
+  \     'col': 41,
+  \     'filename': ale#path#Simplify(g:dir . '/main.tf'),
+  \     'type': 'E',
+  \     'text': 'storage_os_disk: required field is not set',
+  \   }
+  \ ],
+  \ ale_linters#terraform#terraform#Handle(bufnr(''), [
+  \ '{',
+  \ '  "valid": false,',
+  \ '  "error_count": 1,',
+  \ '  "warning_count": 0,',
+  \ '  "diagnostics": [',
+  \ '    {',
+  \ '      "severity": "error",',
+  \ '      "summary": "storage_os_disk: required field is not set",',
+  \ '      "detail": "",',
+  \ '      "range": {',
+  \ '        "filename": "main.tf",',
+  \ '        "start": {',
+  \ '          "line": 91,',
+  \ '          "column": 41,',
+  \ '          "byte": 2381',
+  \ '        },',
+  \ '        "end": {',
+  \ '          "line": 91,',
+  \ '          "column": 41,',
+  \ '          "byte": 2381',
+  \ '        }',
+  \ '      }',
+  \ '    }',
+  \ '  ]',
+  \ '}'
+  \ ])