chore: fix eslint errors

Author: Dschungelabenteuer

packages/core/tests/cases/mixed-imports/setup.ts

@@ -43,6 +43,7 @@ export function testMixedImportsOfTarget(middleTarget?: CaseTarget) {
       const target = await createCaseTarget(targetName, 1);
       const { importPath, targetList } = setupCase(target, middleTarget);
       const input = `import Entry, { MixedDefault } from '${importPath}';\n`;
+      // eslint-disable-next-line @typescript-eslint/no-unnecessary-type-conversion
       const output = ''
         + `import { default as MixedDefault } from '${resolved}';\n`
         + `import { default as Entry } from '${importPath}';\n`

packages/core/tests/utils.ts

@@ -262,8 +262,7 @@ export async function resolveUnitEntry(name: string) {
  * It creates it if it doesn't exist yet.
  */
 async function getResolver() {
-  if (!testResolver) testResolver = await getTestResolver();
-  return testResolver;
+  return testResolver ??= await getTestResolver();
 }
 
 /**