JSX-A11Y label-has-for Configuration (#7)

* Adjust jsx-a11y linter label-has-for rule.
Allow inputs to have sibling labels with an id associated by htmlFor rather than force labels to wrap around the input.

* Add spec for label-has-for exception.
Demonstrate example of using htmlFor with id for label and inputs for the label-has-for exception introduced in this commit: eb6e63b.

packages/eslint-config/eslintrc.json

@@ -10,7 +10,17 @@
   "rules": {
     "max-len": ["error", 100],
     "prefer-const": "error",
-    "no-var": "error"
+    "no-var": "error",
+    "jsx-a11y/label-has-for": [
+      2,
+      {
+        "required": {
+          "every": [
+            "id"
+          ]
+        }
+      }
+    ]
   },
   "env": {
     "mocha": true,

packages/eslint-config/test/index.js

@@ -54,3 +54,11 @@ test('disallows a11y violations', t => {
   t.is(result.errorCount, 1)
   t.is(result.messages[0].ruleId, 'jsx-a11y/alt-text')
 })
+
+test('makes exception for jsx-a11y label-has-for rule', t => {
+  const result = lint(
+    `const template = <div><label htmlFor='checkbox'>label</label>
+  <input id='checkbox' type='checkbox' /></div>`
+  )
+  t.is(result.errorCount, 0)
+})