feat: InMemoryCache implementation

api-server/server/utils/in-memory-cache.js

@@ -0,0 +1,34 @@
+function isPromiseLike(thing) {
+  return !!thing && typeof thing.then === 'function';
+}
+
+function InMemoryCache(initialValue) {
+  const cacheKey = Symbol('cacheKey');
+  const cache = new Map();
+
+  if (typeof initialValue !== 'undefined') {
+    cache.set(cacheKey, initialValue);
+  }
+
+  return {
+    get() {
+      const value = cache.get(cacheKey);
+      return typeof value !== 'undefined' ? value : null;
+    },
+    async update(fn) {
+      const maybePromisedValue = fn();
+      if (isPromiseLike(maybePromisedValue)) {
+        return maybePromisedValue.then(value => cache.set(cacheKey, value));
+      } else {
+        const value = maybePromisedValue;
+        cache.set(cacheKey, value);
+        return null;
+      }
+    },
+    clear() {
+      return cache.delete(cacheKey);
+    }
+  };
+}
+
+export default InMemoryCache;