[eslint-plugin-react-hooks]: handling sparse array when no-inline callback (facebook#19145)

Author: yeonjuan

packages/eslint-plugin-react-hooks/__tests__/ESLintRuleExhaustiveDeps-test.js

@@ -369,6 +369,20 @@ const tests = {
         }
       `,
     },
+    {
+      code: normalizeIndent`
+        function MyComponent({myEffect}) {
+          useEffect(myEffect, [,myEffect]);
+        }
+      `,
+    },
+    {
+      code: normalizeIndent`
+        function MyComponent({myEffect}) {
+          useEffect(myEffect, [,myEffect,,]);
+        }
+      `,
+    },
     {
       code: normalizeIndent`
         let local = {};

packages/eslint-plugin-react-hooks/src/ExhaustiveDeps.js

@@ -145,7 +145,7 @@ export default {
           if (
             declaredDependenciesNode.elements &&
             declaredDependenciesNode.elements.some(
-              el => el.type === 'Identifier' && el.name === callback.name,
+              el => el && el.type === 'Identifier' && el.name === callback.name,
             )
           ) {
             // If it's already in the list of deps, we don't care because