fix(eslint-plugin): [prefer-for-of] fix false positive when using erasable type syntax within update expressions (typescript-eslint#10981)

* fix(eslint-plugin): [prefer-for-of] fix false positive when using non-null assertion within update expressions

* fix(eslint-plugin): fix `isAssignee` function to handle any erasable type syntaxes

Author: zyoshoka

packages/eslint-plugin/src/util/isAssignee.ts

@@ -53,5 +53,16 @@ export function isAssignee(node: TSESTree.Node): boolean {
     return true;
   }
 
+  // (a[i] as number)++, [...a[i]!] = [0], etc.
+  if (
+    (parent.type === AST_NODE_TYPES.TSNonNullExpression ||
+      parent.type === AST_NODE_TYPES.TSAsExpression ||
+      parent.type === AST_NODE_TYPES.TSTypeAssertion ||
+      parent.type === AST_NODE_TYPES.TSSatisfiesExpression) &&
+    isAssignee(parent)
+  ) {
+    return true;
+  }
+
   return false;
 }

packages/eslint-plugin/tests/rules/prefer-for-of.test.ts

@@ -139,6 +139,46 @@ for (let i = 0; i < arr.length; i++) {
 }
     `,
     `
+for (let i = 0; i < arr.length; i++) {
+  arr[i]++;
+}
+    `,
+    `
+for (let i = 0; i < arr.length; i++) {
+  arr[i]!++;
+}
+    `,
+    `
+for (let i = 0; i < arr.length; i++) {
+  arr[i]!!!++;
+}
+    `,
+    `
+for (let i = 0; i < arr.length; i++) {
+  (arr[i] as number)++;
+}
+    `,
+    `
+for (let i = 0; i < arr.length; i++) {
+  (<number>arr[i])++;
+}
+    `,
+    `
+for (let i = 0; i < arr.length; i++) {
+  (arr[i] as unknown as number)++;
+}
+    `,
+    `
+for (let i = 0; i < arr.length; i++) {
+  (arr[i] satisfies number)++;
+}
+    `,
+    `
+for (let i = 0; i < arr.length; i++) {
+  (arr[i]! satisfies number)++;
+}
+    `,
+    `
 for (let i = 0; i < arr.length; i++) {
   [arr[i]] = [1];
 }
@@ -149,6 +189,11 @@ for (let i = 0; i < arr.length; i++) {
 }
     `,
     `
+for (let i = 0; i < arr.length; i++) {
+  [...arr[i]!] = [1];
+}
+    `,
+    `
 for (let i = 0; i < arr.length; i++) {
   ({ foo: arr[i] }) = { foo: 0 };
 }