Initial implementation of jsx-no-namespace

README.md

@@ -175,6 +175,7 @@ Enable the rules that you would like to use.
 * [react/jsx-no-comment-textnodes](docs/rules/jsx-no-comment-textnodes.md): Comments inside children section of tag should be placed inside braces
 * [react/jsx-no-duplicate-props](docs/rules/jsx-no-duplicate-props.md): Enforce no duplicate props
 * [react/jsx-no-literals](docs/rules/jsx-no-literals.md): Prevent using string literals in React component definition
+* [react/jsx-no-namespace](docs/rules/jsx-no-namespace.md): Enforce that namespaces are not used in JSX
 * [react/jsx-no-script-url](docs/rules/jsx-no-script-url.md): Forbid `javascript:` URLs
 * [react/jsx-no-target-blank](docs/rules/jsx-no-target-blank.md): Forbid `target="_blank"` attribute without `rel="noreferrer"`
 * [react/jsx-no-undef](docs/rules/jsx-no-undef.md): Disallow undeclared variables in JSX

docs/rules/jsx-no-namespace.md

@@ -0,0 +1,29 @@
+# Enforce that namespaces are not used in JSX (react/jsx-no-namespace)
+
+Enforces the absence of a namespace in JSX components, such as with `svg:circle`, as they are not supported in React.
+
+## Rule Details
+
+The following patterns are considered warnings:
+
+```jsx
+<ns:TestComponent />
+```
+
+```jsx
+<Ns:TestComponent />
+```
+
+The following patterns are **not** considered warnings:
+
+```jsx
+<TestComponent />
+```
+
+```jsx
+<testComponent />
+```
+
+## When not to use
+
+If you are not using JSX.

index.js

@@ -35,6 +35,7 @@ const allRules = {
   'jsx-no-comment-textnodes': require('./lib/rules/jsx-no-comment-textnodes'),
   'jsx-no-duplicate-props': require('./lib/rules/jsx-no-duplicate-props'),
   'jsx-no-literals': require('./lib/rules/jsx-no-literals'),
+  'jsx-no-namespace': require('./lib/rules/jsx-no-namespace'),
   'jsx-no-script-url': require('./lib/rules/jsx-no-script-url'),
   'jsx-no-target-blank': require('./lib/rules/jsx-no-target-blank'),
   'jsx-no-useless-fragment': require('./lib/rules/jsx-no-useless-fragment'),
@@ -126,6 +127,7 @@ module.exports = {
         'react/jsx-key': 2,
         'react/jsx-no-comment-textnodes': 2,
         'react/jsx-no-duplicate-props': 2,
+        'react/jsx-no-namespace': 2,
         'react/jsx-no-target-blank': 2,
         'react/jsx-no-undef': 2,
         'react/jsx-uses-react': 2,

lib/rules/jsx-no-namespace.js

@@ -0,0 +1,40 @@
+/**
+ * @fileoverview Enforce that namespaces are not used in JSX
+ * @author Yacine Hmito
+ */
+
+'use strict';
+
+const elementType = require('jsx-ast-utils/elementType');
+const docsUrl = require('../util/docsUrl');
+
+// ------------------------------------------------------------------------------
+// Rule Definition
+// ------------------------------------------------------------------------------
+
+module.exports = {
+  meta: {
+    docs: {
+      description: 'Enforce that namespaces are not used in JSX',
+      category: 'Possible Errors',
+      recommended: true,
+      url: docsUrl('jsx-no-namespace')
+    },
+
+    schema: [{
+      type: 'object',
+      additionalProperties: false
+    }]
+  },
+
+  create(context) {
+    return {
+      JSXOpeningElement(node) {
+        const name = elementType(node);
+        if (name.indexOf(':') === -1) return undefined;
+        const message = `JSX component ${name} must not be in a namespace as React does not support them`;
+        context.report({node, message});
+      }
+    };
+  }
+};

tests/lib/rules/jsx-no-namespace.js

@@ -0,0 +1,80 @@
+/**
+ * @fileoverview Tests for jsx-no-namespace
+ * @author Yacine Hmito
+ */
+
+'use strict';
+
+// ------------------------------------------------------------------------------
+// Requirements
+// ------------------------------------------------------------------------------
+
+const RuleTester = require('eslint').RuleTester;
+const rule = require('../../../lib/rules/jsx-no-namespace');
+
+const parserOptions = {
+  ecmaVersion: 2018,
+  sourceType: 'module',
+  ecmaFeatures: {
+    jsx: true
+  }
+};
+
+// ------------------------------------------------------------------------------
+// Tests
+// ------------------------------------------------------------------------------
+
+const ruleTester = new RuleTester({parserOptions});
+ruleTester.run('jsx-no-namespace', rule, {
+  valid: [{
+    code: '<testcomponent />'
+  }, {
+    code: '<testComponent />'
+  }, {
+    code: '<test_component />'
+  }, {
+    code: '<TestComponent />'
+  }, {
+    code: '<object.testcomponent />'
+  }, {
+    code: '<object.testComponent />'
+  }, {
+    code: '<object.test_component />'
+  }, {
+    code: '<object.TestComponent />'
+  }, {
+    code: '<Object.testcomponent />'
+  }, {
+    code: '<Object.testComponent />'
+  }, {
+    code: '<Object.test_component />'
+  }, {
+    code: '<Object.TestComponent />'
+  }],
+
+  invalid: [{
+    code: '<ns:testcomponent />',
+    errors: [{message: 'JSX component ns:testcomponent must not be in a namespace as React does not support them'}]
+  }, {
+    code: '<ns:testComponent />',
+    errors: [{message: 'JSX component ns:testComponent must not be in a namespace as React does not support them'}]
+  }, {
+    code: '<ns:test_component />',
+    errors: [{message: 'JSX component ns:test_component must not be in a namespace as React does not support them'}]
+  }, {
+    code: '<ns:TestComponent />',
+    errors: [{message: 'JSX component ns:TestComponent must not be in a namespace as React does not support them'}]
+  }, {
+    code: '<Ns:testcomponent />',
+    errors: [{message: 'JSX component Ns:testcomponent must not be in a namespace as React does not support them'}]
+  }, {
+    code: '<Ns:testComponent />',
+    errors: [{message: 'JSX component Ns:testComponent must not be in a namespace as React does not support them'}]
+  }, {
+    code: '<Ns:test_component />',
+    errors: [{message: 'JSX component Ns:test_component must not be in a namespace as React does not support them'}]
+  }, {
+    code: '<Ns:TestComponent />',
+    errors: [{message: 'JSX component Ns:TestComponent must not be in a namespace as React does not support them'}]
+  }]
+});