fix: add javascript patterns examples files (#1266)

examples/nodejs/cache/doc-example-files/patterns.ts

@@ -0,0 +1,55 @@
+/**
+ *
+ * This file contains examples of consuming the JavaScript APIs, for use as examples
+ * in the public dev docs.  Each function name that begins with `example_` is available
+ * to the dev docs to inject into the code snippets widget for the specified API.
+ *
+ * These examples should all be JavaScript; we can add TypeScript-specific examples in
+ * a second file in the future if desired.
+ *
+ */
+import {CacheClient, Configurations, CredentialProvider} from '@gomomento/sdk';
+
+const database: Map<string, string> = new Map();
+database.set('test-key', 'test-value');
+
+/* eslint-disable @typescript-eslint/no-unused-vars */
+async function example_patterns_ReadAsideCaching(cacheClient: CacheClient): Promise<string> {
+  const cachedValue = (await cacheClient.get('test-cache', 'test-key')).value();
+  if (cachedValue !== undefined) {
+    console.log(`Cache hit for key 'test-key': ${cachedValue}`);
+    return cachedValue;
+  } else {
+    console.log("Key 'test-key' was not found in cache 'test-cache', checking in database...");
+    // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
+    const actualValue = database.get('test-key')!;
+    await cacheClient.set('test-cache', 'test-key', actualValue);
+    return actualValue;
+  }
+}
+
+/* eslint-disable @typescript-eslint/no-unused-vars */
+async function example_patterns_WriteThroughCaching(cacheClient: CacheClient): Promise<string> {
+  const value = 'test-value';
+  database.set('test-key', value);
+  await cacheClient.set('test-cache', 'test-key', value);
+  return value;
+}
+
+async function main() {
+  const cacheClient = await CacheClient.create({
+    configuration: Configurations.Laptop.v1(),
+    credentialProvider: CredentialProvider.fromEnvironmentVariable({
+      environmentVariableName: 'MOMENTO_API_KEY',
+    }),
+    defaultTtlSeconds: 60,
+  });
+  await cacheClient.createCache('test-cache');
+
+  await example_patterns_ReadAsideCaching(cacheClient);
+  await example_patterns_WriteThroughCaching(cacheClient);
+}
+
+main().catch(e => {
+  throw e;
+});