Fix: 24 | additional null check for initial call arguments (#25)

* add null check for args

on proxy member expressions, for any calls that do not have any args

* fix snapshot for no deps on useEffect

additional test case for snapshot changes where the useEffect might not
have any deps and still needs to error out

Author: barelyhuman

src/StateSnapshot.js

@@ -307,7 +307,8 @@ function isUsedInUseProxy(node, scope) {
       (init.type === 'CallExpression' && init.callee.name === 'useSnapshot')
     ) {
       if (
-        (init.arguments[0] &&
+        (init.arguments.length > 0 &&
+          init.arguments[0] &&
           init.arguments[0]._babelType === 'MemberExpression' &&
           node._babelType === 'MemberExpression') ||
         (init.arguments[0] &&

src/lib/utils.js

@@ -205,7 +205,10 @@ export function isInHookDeps(node) {
   }
 
   const flatDepPaths = []
-  allDepExpressions.elements.forEach((exprNode) => {
+
+  // Handle cases where the elements might not exist at all ,
+  // aka useEffect(()=>{}) without a dep array
+  ;(allDepExpressions.elements || []).forEach((exprNode) => {
     let exprPath
     if (exprNode.type === 'MemberExpression') {
       exprPath = flattenMemberExpression(exprNode)

tests/StateSnapshot.test.js

@@ -317,5 +317,18 @@ ruleTester.run('state-snapshot-rule', rule, {
           }`,
       errors: [SNAPSHOT_CALLBACK_MESSAGE],
     },
+    {
+      code: `
+          function useExample2(s) {
+            const {b: {c} } = useSnapshot(s.a1);
+
+            useEffect(() => {
+              if (c === 'a1c') {
+                state.a1.b.c = 'example';
+              }
+            });
+          }`,
+      errors: [SNAPSHOT_CALLBACK_MESSAGE],
+    },
   ],
 })