refactor(util/cache): Enable strict nulls (#12887)

lib/util/cache/repository/index.ts

@@ -11,16 +11,16 @@ import type { Cache } from './types';
 // Increment this whenever there could be incompatibilities between old and new cache structure
 export const CACHE_REVISION = 9;
 
-let repositoryCache: RepositoryCacheConfig = 'disabled';
-let cacheFileName: string;
-let cache: Cache = Object.create({});
+let repositoryCache: RepositoryCacheConfig | undefined = 'disabled';
+let cacheFileName: string | null = null;
+let cache: Cache | null = Object.create({});
 
 export function getCacheFileName(config: RenovateConfig): string {
   return join(
     GlobalConfig.get('cacheDir'),
     '/renovate/repository/',
     config.platform,
-    config.repository + '.json'
+    `${config.repository}.json`
   );
 }
 
@@ -63,7 +63,7 @@ export async function initialize(config: RenovateConfig): Promise<void> {
 }
 
 export function getCache(): Cache {
-  return cache || createCache();
+  return cache ?? createCache();
 }
 
 export async function finalize(): Promise<void> {

tsconfig.strict.json

@@ -23,7 +23,7 @@
     "lib/platform/utils/pr-body.ts",
     "lib/proxy.ts",
     "lib/types/**/*.ts",
-    "lib/util/cache/package/*.ts",
+    "lib/util/cache/*.ts",
     "lib/util/clone.ts",
     "lib/util/date.ts",
     "lib/util/exec/common.ts",
@@ -66,6 +66,6 @@
     "lib/datasource/helm/common.ts",
     "lib/logger/err-serializer.spec.ts",
     "lib/manager/gradle/shallow/types.ts",
-    "lib/util/cache/package/*.spec.ts"
+    "lib/util/cache/*.spec.ts"
   ]
 }