test: add tests for eslint rules

This adds tests for the custom eslint rules in this repository, using
the `RuleTester` test utility bundled with eslint.

PR-URL: https://github.com/nodejs/node/pull/16138
Reviewed-By: Rich Trott <rtrott@gmail.com>
Reviewed-By: Yuta Hiroto <hello@about-hiroppy.com>
Reviewed-By: James M Snell <jasnell@gmail.com>

1 files changed, 26 insertions, 0 deletions

diff --git a/test/parallel/test-eslint-alphabetize-errors.js b/test/parallel/test-eslint-alphabetize-errors.js
new file mode 100644
index 0000000000..83c73fc78c
--- /dev/null
+++ b/test/parallel/test-eslint-alphabetize-errors.js
@@ -0,0 +1,26 @@
+'use strict';
+
+require('../common');
+
+const RuleTester = require('../../tools/eslint').RuleTester;
+const rule = require('../../tools/eslint-rules/alphabetize-errors');
+
+new RuleTester().run('alphabetize-errors', rule, {
+  valid: [
+    `
+      E('AAA', 'foo');
+      E('BBB', 'bar');
+      E('CCC', 'baz');
+    `
+  ],
+  invalid: [
+    {
+      code: `
+        E('BBB', 'bar');
+        E('AAA', 'foo');
+        E('CCC', 'baz');
+      `,
+      errors: [{ message: 'Out of ASCIIbetical order - BBB >= AAA', line: 3 }]
+    }
+  ]
+});