From dd2d202d1b65c58ec0ea394ae2372e68af5438af Mon Sep 17 00:00:00 2001
From: Duncan Beevers <duncan@dweebd.com>
Date: Wed, 27 Oct 2021 16:33:02 -0700
Subject: [PATCH] Handle no-init let-declared dependency identifier

Closes #4
---
 __tests__/require-usememo.ts | 8 ++++++++
 common.ts                    | 4 ++++
 2 files changed, 12 insertions(+)

diff --git a/__tests__/require-usememo.ts b/__tests__/require-usememo.ts
index cbe60de..19268c8 100644
--- a/__tests__/require-usememo.ts
+++ b/__tests__/require-usememo.ts
@@ -142,5 +142,13 @@ ruleTester.run("useMemo", rule, {
       options: [{ strict: true }],
       errors: [{ messageId: "unknown-usememo-props" }],
     },
+    {
+      code: `const Component = () => {
+        let myObject;
+        myObject = {};
+        return <Child prop={myObject} />;
+      }`,
+      errors: [{ messageId: "usememo-const" }],
+    },
   ],
 });
diff --git a/common.ts b/common.ts
index 4512d15..16b9698 100644
--- a/common.ts
+++ b/common.ts
@@ -53,6 +53,10 @@ function getIdentifierMemoStatus(
   if (node.type !== "VariableDeclarator") return MemoStatus.Memoized;
   if (node.parent.kind === "let") {
     context.report({ node, messageId: "usememo-const" });
+    if (!node.init) {
+      // Rely on usememo-const reported error to fail this identifier
+      return MemoStatus.Memoized;
+    }
   }
   return getExpressionMemoStatus(context, node.init);
 }