Add Upstash APL (#78)

.eslintrc

@@ -9,7 +9,7 @@
     "plugin:@typescript-eslint/recommended",
     "prettier" // prettier *has* to be the last one, to avoid conflicting rules
   ],
-  "ignorePatterns": ["pnpm-lock.yaml", "dist"],
+  "ignorePatterns": ["pnpm-lock.yaml", "dist", "coverage"],
   "plugins": ["simple-import-sort", "@typescript-eslint"],
   "rules": {
     "import/no-extraneous-dependencies": ["error", { "devDependencies": true }],

.prettierignore

@@ -3,4 +3,5 @@ saleor/api.tsx
 pnpm-lock.yaml
 graphql.schema.json
 lib/$path.ts
-dist
+dist
+coverage

docs/apl.md

@@ -137,3 +137,22 @@ sequenceDiagram
     SSI->>V: Set auth data as environment variables
     V->>A: Redeploy the application
 ```
+
+### UpstashAPL
+
+[Upstash](https://upstash.com) is a Redis SaaS targeting serverless applications. It's free tier is more than enough to start developing multi-tenant Saleor Apps, and credit card info is not required to create an account.
+
+APL implementation use REST endpoints to store the data, so no extra dependencies are required.
+
+To use UpstashAPL, you'll need endpoint URL and password. Both will be available at [dashboard](https://console.upstash.com/) after creating a database. Credentials can be passed to APL during it's creation:
+
+```ts
+import { UpstashAPL } from "@saleor/app-sdk/APL";
+
+const apl = new UpstashAPL({
+  restToken: "XXXXXXXXXXXXXX",
+  restUrl: "https://eu2-red-panda-00000.upstash.io",
+});
+```
+
+Or using environment variables: `UPSTASH_TOKEN`, `UPSTASH_URL`.

src/APL/index.ts

@@ -1,3 +1,4 @@
 export * from "./apl";
 export * from "./file-apl";
+export * from "./upstash-apl";
 export * from "./vercel-apl";

src/APL/upstash-apl.test.ts

@@ -0,0 +1,137 @@
+import fetch from "node-fetch";
+import { afterEach, describe, expect, it, vi } from "vitest";
+
+import { AuthData } from "./apl";
+import { UpstashAPL, UpstashAPLConfig, UpstashAPLVariables } from "./upstash-apl";
+
+vi.mock("node-fetch", () => ({
+  default: vi.fn().mockImplementation(() => ""),
+}));
+
+const mockFetch = vi.mocked(fetch);
+
+const aplConfig: UpstashAPLConfig = {
+  restToken: "token",
+  restURL: "http://example.com",
+};
+
+const stubAuthData: AuthData = {
+  domain: "example.com",
+  token: "example-token",
+};
+
+describe("APL", () => {
+  const initialEnv = { ...process.env };
+
+  afterEach(() => {
+    process.env = { ...initialEnv };
+    vi.resetModules();
+  });
+
+  describe("UpstashAPL", () => {
+    it("Test if constructor use options over environment variables", async () => {
+      process.env[UpstashAPLVariables.UPSTASH_TOKEN] = "environment";
+      process.env[UpstashAPLVariables.UPSTASH_URL] = "environment";
+
+      const apl = await new UpstashAPL({ restToken: "option", restURL: "option" });
+      // eslint-disable-next-line dot-notation
+      expect(apl["restToken"]).toBe("option");
+      // eslint-disable-next-line dot-notation
+      expect(apl["restURL"]).toBe("option");
+    });
+
+    describe("set", () => {
+      it("Successful save of the auth data", async () => {
+        // @ts-ignore Ignore type of mocked response
+        mockFetch.mockResolvedValue({
+          status: 200,
+          json: async () => ({ result: "ok" }),
+        });
+        const apl = new UpstashAPL({
+          restURL: "https://example.com",
+          restToken: "token",
+        });
+        await apl.set({ domain: "example.com", token: "token" });
+        expect(mockFetch).toBeCalledWith(
+          "https://example.com",
+
+          {
+            // eslint-disable-next-line quotes
+            body: '["SET", "example.com", "token"]',
+            headers: {
+              "Content-Type": "application/json",
+              Authorization: "Bearer token",
+            },
+            method: "POST",
+          }
+        );
+      });
+
+      it("Raise error when register service returns non 200 response", async () => {
+        // @ts-ignore Ignore type of mocked response
+        mockFetch.mockResolvedValue({ status: 500 });
+
+        const apl = new UpstashAPL({
+          restURL: "https://example.com",
+          restToken: "token",
+        });
+        await expect(apl.set({ domain: "example.com", token: "token" })).rejects.toThrow(
+          "Upstash APL responded with the code 500"
+        );
+      });
+    });
+
+    describe("get", () => {
+      describe("Read existing auth data from env", () => {
+        it("Read existing auth data", async () => {
+          // @ts-ignore Ignore type of mocked response
+          mockFetch.mockResolvedValue({
+            status: 200,
+            json: async () => ({
+              result: stubAuthData.token,
+            }),
+          });
+          const apl = new UpstashAPL(aplConfig);
+
+          expect(await apl.get(stubAuthData.domain)).toStrictEqual(stubAuthData);
+        });
+
+        it("Return undefined when unknown domain requested", async () => {
+          // @ts-ignore Ignore type of mocked response
+          mockFetch.mockResolvedValue({
+            status: 200,
+            json: async () => ({
+              result: null,
+            }),
+          });
+          const apl = new UpstashAPL(aplConfig);
+
+          expect(await apl.get("unknown-domain.example.com")).toBe(undefined);
+        });
+      });
+    });
+
+    describe("getAll", () => {
+      describe("Check if error is raised", () => {
+        it("Read existing auth data", async () => {
+          const apl = new UpstashAPL(aplConfig);
+          await expect(apl.getAll()).rejects.toThrow("UpstashAPL does not support getAll method");
+        });
+      });
+    });
+
+    describe("isReady", () => {
+      it("Returns error with message mentioning missing configuration variables", async () => {
+        const apl = new UpstashAPL();
+
+        const result = await apl.isReady();
+        expect(result.ready).toBeFalsy();
+        // @ts-ignore
+        expect(result.error.message).toEqual(
+          // eslint-disable-next-line quotes
+          'Configuration values for: "restToken", "restURL" not found or is empty. Pass values to constructor of use env variables.'
+        );
+      });
+    });
+  });
+});

src/APL/upstash-apl.ts

@@ -0,0 +1,162 @@
+/* eslint-disable class-methods-use-this */
+// eslint-disable-next-line max-classes-per-file
+import fetch, { Response } from "node-fetch";
+
+import { APL, AplConfiguredResult, AplReadyResult, AuthData } from "./apl";
+import { createAPLDebug } from "./apl-debug";
+
+const debug = createAPLDebug("UpstashAPL");
+
+type SuccessResponse = { result: string };
+type ErrorResponse = { error: string };
+type UpstashResponse = SuccessResponse | ErrorResponse;
+
+export const UpstashAPLVariables = {
+  UPSTASH_TOKEN: "UPSTASH_TOKEN",
+  UPSTASH_URL: "UPSTASH_URL",
+};
+
+export class UpstashAplMisconfiguredError extends Error {
+  constructor(public missingVars: string[]) {
+    super(
+      `Configuration values for: ${missingVars
+        .map((v) => `"${v}"`)
+        .join(", ")} not found or is empty. Pass values to constructor of use env variables.`
+    );
+  }
+}
+
+export class UpstashAplNotConfiguredError extends Error {}
+
+export type UpstashAPLConfig = {
+  restURL: string;
+  restToken: string;
+};
+
+/**
+ * Upstash APL
+ *
+ * Use [Upstash](https://upstash.com) which is SaaS Redis provider, to store auth data.
+ * You can create free developer account and use it to develop multi-tenant apps.
+ *
+ * Configuration require 2 elements: URL to the REST service and auth token. Both can be
+ * found in the Upstash dashboard. You can choose to store them using environment variables
+ * (`UPSTASH_URL` and `UPSTASH_TOKEN`) or pass directly to APL's constructor.
+ */
+export class UpstashAPL implements APL {
+  private restURL?: string;
+
+  private restToken?: string;
+
+  constructor(config?: UpstashAPLConfig) {
+    const restURL = config?.restURL || process.env[UpstashAPLVariables.UPSTASH_URL];
+    const restToken = config?.restToken || process.env[UpstashAPLVariables.UPSTASH_TOKEN];
+
+    this.restURL = restURL;
+    this.restToken = restToken;
+  }
+
+  private async upstashRequest(requestBody: string) {
+    debug("Sending request to Upstash");
+    if (!this.restURL || !this.restToken) {
+      throw new Error(
+        "UpstashAPL is not configured. See https://github.com/saleor/saleor-app-sdk/blob/main/docs/apl.md"
+      );
+    }
+    let response: Response;
+    try {
+      response = await fetch(this.restURL, {
+        method: "POST",
+        headers: { "Content-Type": "application/json", Authorization: `Bearer ${this.restToken}` },
+        body: requestBody,
+      });
+    } catch (error) {
+      debug("Error during sending the data:", error);
+      throw new Error(`UpstashAPL was unable to perform a request ${error}`);
+    }
+    if (response.status >= 400 || response.status < 200) {
+      debug("Non 200 response code. Upstash responded with %j", response);
+      throw new Error(`Upstash APL responded with the code ${response.status}`);
+    }
+    const parsedResponse = (await response.json()) as UpstashResponse;
+    if ("error" in parsedResponse) {
+      debug("Upstash API responded with error: %s", parsedResponse.error);
+      throw new Error("Upstash APL was not able to perform operation");
+    }
+    debug("Register service responded successfully");
+    return parsedResponse.result;
+  }
+
+  private async saveDataToUpstash(authData?: AuthData) {
+    debug("saveDataToUpstash() called with: %j", {
+      domain: authData?.domain,
+      token: authData?.token.substring(0, 4),
+    });
+
+    await this.upstashRequest(`["SET", "${authData?.domain}", "${authData?.token}"]`);
+  }
+
+  private async deleteDataFromUpstash(domain: string) {
+    await this.upstashRequest(`["DEL", "${domain}"]`);
+  }
+
+  private async fetchDataFromUpstash(domain: string) {
+    const result = await this.upstashRequest(`["GET", "${domain}"]`);
+    if (result) {
+      return { domain, token: result };
+    }
+    return undefined;
+  }
+
+  async get(domain: string) {
+    return this.fetchDataFromUpstash(domain);
+  }
+
+  async set(authData: AuthData) {
+    await this.saveDataToUpstash(authData);
+  }
+
+  async delete(domain: string) {
+    await this.deleteDataFromUpstash(domain);
+  }
+
+  async getAll() {
+    throw new Error("UpstashAPL does not support getAll method");
+    return [];
+  }
+
+  // eslint-disable-next-line class-methods-use-this
+  async isReady(): Promise<AplReadyResult> {
+    const missingConf: string[] = [];
+    if (!this.restToken) {
+      missingConf.push("restToken");
+    }
+    if (!this.restURL) {
+      missingConf.push("restURL");
+    }
+
+    if (missingConf.length > 0) {
+      return {
+        ready: false,
+        error: new UpstashAplMisconfiguredError(missingConf),
+      };
+    }
+
+    return {
+      ready: true,
+    };
+  }
+
+  async isConfigured(): Promise<AplConfiguredResult> {
+    return this.restToken && this.restURL
+      ? {
+          configured: true,
+        }
+      : {
+          configured: false,
+          error: new UpstashAplNotConfiguredError(
+            "UpstashAPL not configured. Check if REST URL and token provided in constructor or env"
+          ),
+        };
+  }
+}