inital #2

src/redis.ts

@@ -0,0 +1,70 @@
+import * as redis from 'redis';
+import {DefaultConfig} from '.';
+import {promisify} from 'util';
+
+interface RedisType {
+	client: redis.RedisClient | undefined;
+	get(key: string): Promise<string | undefined>;
+	set(key: string, value: string): Promise<void>;
+	del(...keys: string[]): Promise<number>;
+}
+
+class RealRedis implements RedisType {
+	private _client: redis.RedisClient|undefined;
+	private _promGet: ((key: string) => Promise<string|null>)|undefined;
+	private _promSet: RedisType["set"]|undefined;
+	private _promDel: RedisType["del"]|undefined;
+
+	get client(): redis.RedisClient {
+		if (this._client !== undefined) return this._client;
+		DefaultConfig.requireEnv('REDIS_URL');
+		this._client = redis.createClient({url: DefaultConfig.REDIS_URL});
+		return this._client;
+	}
+
+	async get(key: string): Promise<string | undefined> {
+		if (!this._promGet) this._promGet = promisify(this.client.get);
+		const value = await this._promGet(key);
+		// eslint-disable-next-line no-null/no-null
+		return value === null ? undefined : value;
+	}
+
+	async set(key: string, value: string): Promise<void> {
+		if (!this._promSet) this._promSet = promisify(this.client.set);
+		await this._promSet(key, value);
+	}
+
+	async del(...keys: string[]): Promise<number> {
+		if (!this._promDel) this._promDel = promisify(this.client.del);
+		return await this._promDel(...keys);
+	}
+}
+
+class MockRedis implements RedisType {
+	private inMemory: {[key: string]: string} = {};
+
+	get client(): undefined {
+		return undefined;
+	}
+
+	async get(key: string): Promise<string | undefined> {
+		return this.inMemory[key] || undefined;
+	}
+
+	async set(key: string, value: string): Promise<void> {
+		this.inMemory[key] = value;
+	}
+
+	async del(...keys: string[]): Promise<number> {
+		for (const key of keys) {
+			delete this.inMemory[key];
+		}
+		return keys.length;
+	}
+}
+
+export const Redis: RedisType =
+	DefaultConfig.REDIS_URL || DefaultConfig.isProduction
+	? new RealRedis()
+	: new MockRedis();
+