fix(check-examples): when matchingFileName used, properly copy parser and load external rules for eslint 6

To test this fix, added a line to an existing test so as to differentiate it from another (and more complex) `.eslintrc.*` (our own project's)

Author: brettz9

README.md

@@ -684,7 +684,18 @@ function quux () {}
 // Message: @example error (semi): Missing semicolon.
 
 /**
- * @example quux2()
+ * @example const i = 5;
+ *          quux2()
+ */
+function quux2 () {
+
+}
+// Settings: {"jsdoc":{"matchingFileName":"test/jsdocUtils.js"}}
+// Message: @example warning (id-length): Identifier name 'i' is too short (< 2).
+
+/**
+ * @example const i = 5;
+ *          quux2()
  */
 function quux2 () {
 

src/rules/checkExamples.js

@@ -149,16 +149,42 @@ export default iterateJsdoc(({
 
     if (filename) {
       const config = cli.getConfigForFile(filename);
+
+      // We need a new instance to ensure that the rules that may only
+      //  be available to `filename` (if it has its own `.eslintrc`),
+      //  will be defined.
+      const cliFile = new CLIEngine({
+        allowInlineConfig,
+        baseConfig: config,
+        configFile,
+        reportUnusedDisableDirectives,
+        rulePaths,
+        rules,
+        useEslintrc: eslintrcForExamples
+      });
+
       const linter = new Linter();
 
-      const linterRules = [...cli.getRules().entries()].reduce((obj, [key, val]) => {
+      // Force external rules to become available on `cli`
+      try {
+        cliFile.executeOnText('');
+      } catch (error) {
+        // Ignore
+      }
+
+      const linterRules = [...cliFile.getRules().entries()].reduce((obj, [key, val]) => {
         obj[key] = val;
 
         return obj;
       }, {});
 
       linter.defineRules(linterRules);
 
+      if (config.parser) {
+        // eslint-disable-next-line global-require, import/no-dynamic-require
+        linter.defineParser(config.parser, require(config.parser));
+      }
+
       // Could also support `disableFixes` and `allowInlineConfig`
       messages = linter.verify(source, config, {
         filename,

test/rules/assertions/checkExamples.js

@@ -301,7 +301,32 @@ export default {
     {
       code: `
           /**
-           * @example quux2()
+           * @example const i = 5;
+           *          quux2()
+           */
+          function quux2 () {
+
+          }
+      `,
+      errors: [
+        {
+          message: '@example warning (id-length): Identifier name \'i\' is too short (< 2).'
+        },
+        {
+          message: '@example error (semi): Missing semicolon.'
+        }
+      ],
+      settings: {
+        jsdoc: {
+          matchingFileName: 'test/jsdocUtils.js'
+        }
+      }
+    },
+    {
+      code: `
+          /**
+           * @example const i = 5;
+           *          quux2()
            */
           function quux2 () {
 

test/rules/data/.eslintrc.json

@@ -1,5 +1,8 @@
 {
   "root": true,
+  "parserOptions": {
+    "ecmaVersion": 8
+  },
   "rules": {
     "semi": ["error", "always"]
   }