[Fix] no-unused-prop-types: apply skipShapeProps to exact types

Fixes #2850.

Author: chiawendt

lib/rules/no-unused-prop-types.js

@@ -70,6 +70,7 @@ module.exports = {
         const usedProp = usedPropTypes[i];
         if (
           prop.type === 'shape'
+          || prop.type === 'exact'
           || prop.name === '__ANY_KEY__'
           || usedProp.name === prop.name
         ) {
@@ -98,7 +99,7 @@ module.exports = {
           return;
         }
 
-        if (prop.type === 'shape' && configuration.skipShapeProps) {
+        if ((prop.type === 'shape' || prop.type === 'exact') && configuration.skipShapeProps) {
           return;
         }
 

tests/lib/rules/no-unused-prop-types.js

@@ -3213,6 +3213,25 @@ ruleTester.run('no-unused-prop-types', rule, {
         Foo.defaultProps = Object.assign({});
       `
     },
+    {
+      code: `
+        const Hello = ({a}) => (
+          <div>
+            {a.map(({b}) => (
+              <div>{b}</div>
+            ))}
+          </div>
+        );
+        Hello.propTypes = {
+          a: PropTypes.arrayOf(
+            PropTypes.exact({
+              b: PropTypes.string,
+            })
+          ),
+        };
+      `,
+      parser: parsers.BABEL_ESLINT
+    },
     parsers.TS([
       {
         code: `