chore: add a tool to decompress cache keys

tools/uncache.ts

@@ -0,0 +1,42 @@
+/**
+ * Decompress and unencode values from the Package Cache or Repository Cache.
+ *
+ * Usage:
+ *
+ *  node tools/uncache.ts "$(redis-cli get "datasource-npm:cache-provider-https://registry.npmjs.org/nock")"
+ *  node tools/uncache.ts ~/Downloads/cache.json
+ *  node tools/uncache.ts G0ohAAQi1GVVr/.......
+ *
+ * Supports:
+ *
+ * - cache values from the Package Cache
+ * - cache values from the Repository Cache
+ */
+import fs from 'fs-extra';
+import { decompressFromBase64 } from '../lib/util/compress.ts';
+
+const input = process.argv[2];
+
+let toDecode = undefined;
+
+if (input.startsWith('{')) {
+  const encoded = JSON.parse(input);
+  toDecode =
+    // if it's from the Package Cache
+    encoded.value ??
+    // if it's from the Repository Cache
+    encoded.payload;
+} else if (await fs.exists(input)) {
+  const encoded = JSON.parse(await fs.readFile(input, 'utf8'));
+
+  toDecode =
+    // if it's from the Package Cache
+    encoded.value ??
+    // if it's from the Repository Cache
+    encoded.payload;
+} else {
+  toDecode = input;
+}
+
+// oxlint-disable-next-line no-console -- intentional: not production code
+console.log(await decompressFromBase64(toDecode));