[Test] parsers.all augments suggestion code output

parsers.all generates an extraComment which is appended to test case examples and their expected output.
Eslint's suggestions API also allows recommended code changes, and RuleTester compares expected changes against generated changes. However, parsers.all didn't augment these expected outputs with the extraComment.

tests/helpers/parsers.js

@@ -66,12 +66,52 @@ const parsers = {
           testObject.parserOptions ? `parserOptions: ${JSON.stringify(testObject.parserOptions)}` : [],
           testObject.options ? `options: ${JSON.stringify(testObject.options)}` : []
         );
+
         const extraComment = `\n// ${extras.join(', ')}`;
+
+        // Augment expected fix code output with extraComment
+        const nextCode = { code: testObject.code + extraComment };
+        const nextOutput = testObject.output && { output: testObject.output + extraComment };
+
+        // Augment expected suggestion outputs with extraComment
+        // `errors` may be a number (expected number of errors) or an array of
+        // error objects.
+        const nextErrors = testObject.errors
+          && typeof testObject.errors !== 'number'
+          && {
+            errors: testObject.errors.map(
+              (errorObject) => {
+                const nextSuggestions = errorObject.suggestions && {
+                  suggestions: errorObject.suggestions.map(
+                    (suggestion) => {
+                      const nextSuggestion = Object.assign(
+                        {},
+                        suggestion,
+                        { output: suggestion.output + extraComment }
+                      );
+
+                      return nextSuggestion;
+                    }
+                  ),
+                };
+
+                const nextErrorObject = Object.assign(
+                  {},
+                  errorObject,
+                  nextSuggestions
+                );
+
+                return nextErrorObject;
+              }
+            ),
+          };
+
         return Object.assign(
           {},
           testObject,
-          { code: testObject.code + extraComment },
-          testObject.output && { output: testObject.output + extraComment }
+          nextCode,
+          nextOutput,
+          nextErrors
         );
       }