Teach no-array-index-key about React.cloneElement

This helps to cover more possible use-cases that we want to prevent with
this rule.

Author: lencioni

docs/rules/no-array-index-key.md

@@ -15,6 +15,10 @@ things.map((thing, index) => (
   <Hello key={index} />
 ));
 
+things.map((thing, index) => (
+  React.cloneElement(thing, { key: index })
+));
+
 things.forEach((thing, index) => {
   otherThings.push(<Hello key={index} />);
 });
@@ -43,6 +47,10 @@ things.map((thing) => (
   <Hello key={thing.id} />
 ));
 
+things.map((thing) => (
+  React.cloneElement(thing, { key: thing.id })
+));
+
 things.forEach((thing) => {
   otherThings.push(<Hello key={thing.id} />);
 });

lib/rules/no-array-index-key.js

@@ -124,7 +124,7 @@ module.exports = {
         if (
           node.callee
           && node.callee.type === 'MemberExpression'
-          && node.callee.property.name === 'createElement'
+          && ['createElement', 'cloneElement'].indexOf(node.callee.property.name) !== -1
           && node.arguments.length > 1
         ) {
           // React.createElement

tests/lib/rules/no-array-index-key.js

@@ -59,6 +59,18 @@ ruleTester.run('no-array-index-key', rule, {
     {
       code: 'foo.map((baz, i) => <Foo key={\'foo\' + baz.id} />)',
       parserOptions: parserOptions
+    },
+
+    {
+      code: [
+        'foo.map((item, i) => {',
+        '  return React.cloneElement(someChild, {',
+        '    key: item.id',
+        '  })',
+        '})'
+      ].join('\n'),
+      errors: [{message: 'Do not use Array index in keys'}],
+      parserOptions: parserOptions
     }
   ],
 
@@ -69,6 +81,12 @@ ruleTester.run('no-array-index-key', rule, {
       parserOptions: parserOptions
     },
 
+    {
+      code: '[{}, {}].map((bar, i) => <Foo key={i} />)',
+      errors: [{message: 'Do not use Array index in keys'}],
+      parserOptions: parserOptions
+    },
+
     {
       code: 'foo.map((bar, anything) => <Foo key={anything} />)',
       errors: [{message: 'Do not use Array index in keys'}],
@@ -93,6 +111,18 @@ ruleTester.run('no-array-index-key', rule, {
       parserOptions: parserOptions
     },
 
+    {
+      code: [
+        'foo.map((item, i) => {',
+        '  return React.cloneElement(someChild, {',
+        '    key: i',
+        '  })',
+        '})'
+      ].join('\n'),
+      errors: [{message: 'Do not use Array index in keys'}],
+      parserOptions: parserOptions
+    },
+
     {
       code: 'foo.forEach((bar, i) => { baz.push(<Foo key={i} />); })',
       errors: [{message: 'Do not use Array index in keys'}],