fix(eslint-plugin): [no-unused-vars] check if any variable definition is exported (#6873)

* fix #6188

* optimize

* add tests

* nit: simplify to .some

---------

Co-authored-by: Josh Goldberg <git@joshuakgoldberg.com>

Author: Maxim-Mazurok

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

@@ -426,9 +426,7 @@ function isMergableExported(variable: TSESLint.Scope.Variable): boolean {
  * @returns True if the variable is exported, false if not.
  */
 function isExported(variable: TSESLint.Scope.Variable): boolean {
-  const definition = variable.defs[0];
-
-  if (definition) {
+  return variable.defs.some(definition => {
     let node = definition.node;
 
     if (node.type === AST_NODE_TYPES.VariableDeclarator) {
@@ -438,8 +436,7 @@ function isExported(variable: TSESLint.Scope.Variable): boolean {
     }
 
     return node.parent!.type.indexOf('Export') === 0;
-  }
-  return false;
+  });
 }
 
 /**

packages/eslint-plugin/tests/rules/no-unused-vars/no-unused-vars.test.ts

@@ -1080,6 +1080,18 @@ export class Foo {
         typescript: '4.4',
       },
     },
+    `
+interface Foo {
+  bar: string;
+}
+export const Foo = 'bar';
+    `,
+    `
+export const Foo = 'bar';
+interface Foo {
+  bar: string;
+}
+    `,
   ],
 
   invalid: [
@@ -1805,5 +1817,25 @@ x = foo(x);
         },
       ],
     },
+    {
+      code: `
+interface Foo {
+  bar: string;
+}
+const Foo = 'bar';
+      `,
+      errors: [
+        {
+          messageId: 'unusedVar',
+          line: 5,
+          column: 7,
+          data: {
+            varName: 'Foo',
+            action: 'assigned a value',
+            additional: '',
+          },
+        },
+      ],
+    },
   ],
 });