[New] prop-types: add skipUnexported option

docs/rules/prop-types.md

@@ -144,14 +144,15 @@ This rule can take one argument to ignore some specific props during validation.
 
 ```js
 ...
-"react/prop-types": [<enabled>, { ignore: <ignore>, customValidators: <customValidator>, skipUndeclared: <skipUndeclared> }]
+"react/prop-types": [<enabled>, { ignore: <ignore>, customValidators: <customValidator>, skipUndeclared: <skipUndeclared>, skipUnexported: <skipUnexported> }]
 ...
 ```
 
 - `enabled`: for enabling the rule. 0=off, 1=warn, 2=error. Defaults to 0.
 - `ignore`: optional array of props name to ignore during validation.
 - `customValidators`: optional array of validators used for propTypes validation.
 - `skipUndeclared`: optional boolean to only error on components that have a propTypes block declared.
+- `skipUnexported`: optional boolean to skip validation for components that are not exported from the module. This is useful when you have helper components or render functions that are only used internally within a file and do not need their own prop types.
 
 ### As for "exceptions"
 

lib/rules/prop-types.js

@@ -52,6 +52,9 @@ module.exports = {
         skipUndeclared: {
           type: 'boolean',
         },
+        skipUnexported: {
+          type: 'boolean',
+        },
       },
       additionalProperties: false,
     }],
@@ -61,6 +64,7 @@ module.exports = {
     const configuration = context.options[0] || {};
     const ignored = configuration.ignore || [];
     const skipUndeclared = configuration.skipUndeclared || false;
+    const skipUnexported = configuration.skipUnexported || false;
 
     /**
      * Checks if the prop is ignored
@@ -71,18 +75,85 @@ module.exports = {
       return ignored.indexOf(name) !== -1;
     }
 
+    const exportedIdentifiers = new Set();
+
+    /**
+     * Get the name of a component from its node
+     * @param {Object} component The component to get the name for
+     * @returns {string | null} The component name, or null if unnamed
+     */
+    function getComponentName(component) {
+      const node = component.node;
+      if (node.id) {
+        return node.id.name;
+      }
+      if (node.parent && node.parent.type === 'VariableDeclarator' && node.parent.id) {
+        return node.parent.id.name;
+      }
+      return null;
+    }
+
+    /**
+     * Checks if a component node is directly in an export declaration
+     * @param {ASTNode} node The component AST node
+     * @returns {boolean} True if the component is directly exported
+     */
+    function isDirectlyExported(node) {
+      let current = node;
+      while (current && current.parent) {
+        const parentType = current.parent.type;
+        if (parentType === 'ExportDefaultDeclaration' || parentType === 'ExportNamedDeclaration') {
+          return true;
+        }
+        if (parentType === 'AssignmentExpression' && current.parent.right === current) {
+          const left = current.parent.left;
+          if (
+            left.type === 'MemberExpression'
+            && left.object.type === 'Identifier'
+            && (
+              (left.object.name === 'module' && left.property.name === 'exports')
+              || left.object.name === 'exports'
+            )
+          ) {
+            return true;
+          }
+        }
+        if (parentType === 'VariableDeclarator' || parentType === 'VariableDeclaration') {
+          current = current.parent;
+          continue; // eslint-disable-line no-continue
+        }
+        break;
+      }
+      return false;
+    }
+
+    /**
+     * Checks if a component is exported from the module
+     * @param {Object} component The component to check
+     * @returns {boolean} True if the component is exported
+     */
+    function isComponentExported(component) {
+      if (isDirectlyExported(component.node)) {
+        return true;
+      }
+      const name = getComponentName(component);
+      return name != null && exportedIdentifiers.has(name);
+    }
+
     /**
      * Checks if the component must be validated
      * @param {Object} component The component to process
      * @returns {boolean} True if the component must be validated, false if not.
      */
     function mustBeValidated(component) {
       const isSkippedByConfig = skipUndeclared && typeof component.declaredPropTypes === 'undefined';
+      const isSkippedAsUnexported = skipUnexported && !isComponentExported(component);
       return !!(
         component
         && component.usedPropTypes
         && !component.ignorePropsValidation
         && !isSkippedByConfig
+        && !isSkippedAsUnexported
       );
     }
 
@@ -210,6 +281,43 @@ module.exports = {
     }
 
     return {
+      ExportDefaultDeclaration(node) {
+        if (node.declaration && node.declaration.type === 'Identifier') {
+          exportedIdentifiers.add(node.declaration.name);
+        }
+      },
+
+      ExportNamedDeclaration(node) {
+        if (node.specifiers) {
+          node.specifiers.forEach((specifier) => {
+            if (specifier.local) {
+              exportedIdentifiers.add(specifier.local.name);
+            }
+          });
+        }
+      },
+
+      AssignmentExpression(node) {
+        if (
+          node.left.type === 'MemberExpression'
+          && node.left.object.type === 'Identifier'
+        ) {
+          if (
+            node.left.object.name === 'module'
+            && node.left.property.name === 'exports'
+            && node.right.type === 'Identifier'
+          ) {
+            exportedIdentifiers.add(node.right.name);
+          }
+          if (
+            node.left.object.name === 'exports'
+            && node.right.type === 'Identifier'
+          ) {
+            exportedIdentifiers.add(node.right.name);
+          }
+        }
+      },
+
       'Program:exit'() {
         const list = components.list();
         // Report undeclared proptypes for all classes

tests/lib/rules/prop-types.js

@@ -1570,6 +1570,102 @@ ruleTester.run('prop-types', rule, {
       `,
       options: [{ skipUndeclared: false }],
     },
+    {
+      code: `
+        function Hello(props) {
+          return <div>{props.name}</div>;
+        }
+      `,
+      options: [{ skipUnexported: true }],
+    },
+    {
+      code: `
+        const Hello = (props) => {
+          return <div>{props.name}</div>;
+        };
+      `,
+      options: [{ skipUnexported: true }],
+    },
+    {
+      code: `
+        class Hello extends React.Component {
+          render() {
+            return <div>{this.props.name}</div>;
+          }
+        }
+      `,
+      options: [{ skipUnexported: true }],
+    },
+    {
+      code: `
+        export function Hello(props) {
+          return <div>{props.name}</div>;
+        }
+        Hello.propTypes = {
+          name: PropTypes.string.isRequired
+        };
+      `,
+      options: [{ skipUnexported: true }],
+    },
+    {
+      code: `
+        export default function Hello(props) {
+          return <div>{props.name}</div>;
+        }
+        Hello.propTypes = {
+          name: PropTypes.string.isRequired
+        };
+      `,
+      options: [{ skipUnexported: true }],
+    },
+    {
+      code: `
+        function Hello(props) {
+          return <div>{props.name}</div>;
+        }
+        Hello.propTypes = {
+          name: PropTypes.string.isRequired
+        };
+        export default Hello;
+      `,
+      options: [{ skipUnexported: true }],
+    },
+    {
+      code: `
+        const Hello = (props) => {
+          return <div>{props.name}</div>;
+        };
+        Hello.propTypes = {
+          name: PropTypes.string.isRequired
+        };
+        export { Hello };
+      `,
+      options: [{ skipUnexported: true }],
+    },
+    {
+      code: `
+        function Hello(props) {
+          return <div>{props.name}</div>;
+        }
+        Hello.propTypes = {
+          name: PropTypes.string.isRequired
+        };
+        module.exports = Hello;
+      `,
+      options: [{ skipUnexported: true }],
+    },
+    {
+      code: `
+        function Hello(props) {
+          return <div>{props.name}</div>;
+        }
+        Hello.propTypes = {
+          name: PropTypes.string.isRequired
+        };
+        exports.Hello = Hello;
+      `,
+      options: [{ skipUnexported: true }],
+    },
     {
       // Async generator functions can't be components.
       code: `
@@ -6727,6 +6823,122 @@ ruleTester.run('prop-types', rule, {
         },
       ],
     },
+    {
+      code: `
+        export function Hello(props) {
+          return <div>{props.name}</div>;
+        }
+      `,
+      options: [{ skipUnexported: true }],
+      errors: [
+        {
+          messageId: 'missingPropType',
+          data: { name: 'name' },
+        },
+      ],
+    },
+    {
+      code: `
+        export default function Hello(props) {
+          return <div>{props.name}</div>;
+        }
+      `,
+      options: [{ skipUnexported: true }],
+      errors: [
+        {
+          messageId: 'missingPropType',
+          data: { name: 'name' },
+        },
+      ],
+    },
+    {
+      code: `
+        export const Hello = (props) => {
+          return <div>{props.name}</div>;
+        };
+      `,
+      options: [{ skipUnexported: true }],
+      errors: [
+        {
+          messageId: 'missingPropType',
+          data: { name: 'name' },
+        },
+      ],
+    },
+    {
+      code: `
+        function Hello(props) {
+          return <div>{props.name}</div>;
+        }
+        export default Hello;
+      `,
+      options: [{ skipUnexported: true }],
+      errors: [
+        {
+          messageId: 'missingPropType',
+          data: { name: 'name' },
+        },
+      ],
+    },
+    {
+      code: `
+        const Hello = (props) => {
+          return <div>{props.name}</div>;
+        };
+        export { Hello };
+      `,
+      options: [{ skipUnexported: true }],
+      errors: [
+        {
+          messageId: 'missingPropType',
+          data: { name: 'name' },
+        },
+      ],
+    },
+    {
+      code: `
+        function Hello(props) {
+          return <div>{props.name}</div>;
+        }
+        module.exports = Hello;
+      `,
+      options: [{ skipUnexported: true }],
+      errors: [
+        {
+          messageId: 'missingPropType',
+          data: { name: 'name' },
+        },
+      ],
+    },
+    {
+      code: `
+        function Hello(props) {
+          return <div>{props.name}</div>;
+        }
+        exports.Hello = Hello;
+      `,
+      options: [{ skipUnexported: true }],
+      errors: [
+        {
+          messageId: 'missingPropType',
+          data: { name: 'name' },
+        },
+      ],
+    },
+    {
+      code: `
+        function Hello(props) {
+          return <div>{props.name}</div>;
+        }
+      `,
+      options: [{ skipUnexported: false }],
+      errors: [
+        {
+          messageId: 'missingPropType',
+          data: { name: 'name' },
+        },
+      ],
+    },
     {
       code: `
         type MyComponentProps = {