Add jsx-no-typeless-button rule

Author: Hypnosphi

docs/rules/jsx-no-typeless-button.md

@@ -0,0 +1,25 @@
+# Prevent usage of `button` elements without an explicit `type` attribute (react/jsx-no-typeless-button)
+
+The default value of `type` attribute for `button` HTML element is `"submit"` which is often not the desired behavior and may lead to unexpected page reloads.
+This rules enforces an explicit `type` attribute for all the `button` elements.
+
+## Rule Details
+
+The following patterns are considered errors:
+
+```jsx
+var Hello = <button>Hello</button>
+```
+
+The following patterns are **not** considered errors:
+
+```jsx
+var Hello = <span>Hello</span>
+var Hello = <button type="button">Hello</button>
+var Hello = <button type="submit">Hello</button>
+var Hello = <button type="reset">Hello</button>
+```
+
+## When Not To Use It
+
+If you use only `"submit"` buttons, you can disable this rule

index.js

@@ -29,6 +29,7 @@ const allRules = {
   'jsx-no-duplicate-props': require('./lib/rules/jsx-no-duplicate-props'),
   'jsx-no-literals': require('./lib/rules/jsx-no-literals'),
   'jsx-no-target-blank': require('./lib/rules/jsx-no-target-blank'),
+  'jsx-no-typeless-button': require('./lib/rules/jsx-no-typeless-button'),
   'jsx-no-undef': require('./lib/rules/jsx-no-undef'),
   'jsx-curly-brace-presence': require('./lib/rules/jsx-curly-brace-presence'),
   'jsx-pascal-case': require('./lib/rules/jsx-pascal-case'),

lib/rules/jsx-no-typeless-button.js

@@ -0,0 +1,41 @@
+/**
+ * @fileoverview Forbid "button" element without an explicit "type" attribute
+ * @author Filipp Riabchun
+ */
+'use strict';
+
+const hasProp = require('jsx-ast-utils/hasProp');
+
+// ------------------------------------------------------------------------------
+// Rule Definition
+// ------------------------------------------------------------------------------
+
+module.exports = {
+  meta: {
+    docs: {
+      description: 'Forbid "button" element without an explicit "type" attribute',
+      category: 'Possible Errors',
+      recommended: false
+    },
+    schema: []
+  },
+
+  create: function(context) {
+    return {
+      JSXElement: function(node) {
+        if (node.openingElement.name.name !== 'button') {
+          return;
+        }
+
+        if (hasProp(node.openingElement.attributes, 'type')) {
+          return;
+        }
+
+        context.report({
+          node: node,
+          message: 'Missing an explicit "type" attribute for button'
+        });
+      }
+    };
+  }
+};

tests/lib/rules/jsx-no-typeless-button.js

@@ -0,0 +1,41 @@
+/**
+ * @fileoverview Forbid "button" element without an explicit "type" attribute
+ * @author Filipp Riabchun
+ */
+'use strict';
+
+// ------------------------------------------------------------------------------
+// Requirements
+// ------------------------------------------------------------------------------
+
+const rule = require('../../../lib/rules/jsx-no-typeless-button');
+const RuleTester = require('eslint').RuleTester;
+
+const parserOptions = {
+  ecmaVersion: 8,
+  sourceType: 'module',
+  ecmaFeatures: {
+    experimentalObjectRestSpread: true,
+    jsx: true
+  }
+};
+
+// ------------------------------------------------------------------------------
+// Tests
+// ------------------------------------------------------------------------------
+
+const ruleTester = new RuleTester({parserOptions});
+ruleTester.run('jsx-no-typeless-button', rule, {
+  valid: [
+    {code: '<span/>'},
+    {code: '<button type="button"/>'},
+    {code: '<button type="submit"/>'},
+    {code: '<button type="reset"/>'}
+  ],
+  invalid: [{
+    code: '<button/>',
+    errors: [{
+      message: 'Missing an explicit "type" attribute for button'
+    }]
+  }]
+});