Refactor PrometheusProviders (#2707)

src/main/__test__/context-handler.test.ts

@@ -0,0 +1,210 @@
+/**
+ * Copyright (c) 2021 OpenLens Authors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of
+ * this software and associated documentation files (the "Software"), to deal in
+ * the Software without restriction, including without limitation the rights to
+ * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
+ * the Software, and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+ * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+ * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
+ * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+import { UserStore } from "../../common/user-store";
+import { ContextHandler } from "../context-handler";
+import { PrometheusProvider, PrometheusProviderRegistry, PrometheusService } from "../prometheus";
+
+enum ServiceResult {
+  Success,
+  Failure,
+  Undefined,
+}
+
+class TestProvider extends PrometheusProvider {
+  name = "TestProvider1";
+  rateAccuracy = "1h";
+  isConfigurable = false;
+
+  constructor(public id: string, public alwaysFail: ServiceResult) {
+    super();
+  }
+
+  getQuery(): string {
+    throw new Error("getQuery is not implemented.");
+  }
+
+  async getPrometheusService(): Promise<PrometheusService> {
+    switch (this.alwaysFail) {
+      case ServiceResult.Success:
+        return {
+          id: this.id,
+          namespace: "default",
+          port: 7000,
+          service: "",
+        };
+      case ServiceResult.Failure:
+        throw new Error("does fail");
+      case ServiceResult.Undefined:
+        return undefined;
+    }
+  }
+}
+
+function getHandler() {
+  return new ContextHandler(({
+    getProxyKubeconfig: (): any => ({
+      makeApiClient: (): any => undefined,
+    }),
+    apiUrl: "http://localhost:81",
+  }) as any);
+}
+
+describe("ContextHandler", () => {
+  beforeEach(() => {
+    PrometheusProviderRegistry.createInstance();
+    UserStore.createInstance();
+  });
+
+  afterEach(() => {
+    PrometheusProviderRegistry.resetInstance();
+    UserStore.resetInstance();
+  });
+
+  describe("getPrometheusService", () => {
+    it.each([
+      [0, 0],
+      [0, 1],
+      [0, 2],
+      [0, 3],
+    ])("should return undefined from %d success(es) after %d failure(s)", async (successes, failures) => {
+      const reg = PrometheusProviderRegistry.getInstance();
+      let count = 0;
+
+      for (let i = 0; i < failures; i += 1) {
+        const serviceResult = i % 2 === 0 ? ServiceResult.Failure : ServiceResult.Undefined;
+
+        reg.registerProvider(new TestProvider(`id_${count++}`, serviceResult));
+      }
+
+      for (let i = 0; i < successes; i += 1) {
+        reg.registerProvider(new TestProvider(`id_${count++}`, ServiceResult.Success));
+      }
+
+      const service = await getHandler().getPrometheusService();
+
+      expect(service).toBeUndefined();
+    });
+
+    it.each([
+      [1, 0],
+      [1, 1],
+      [1, 2],
+      [1, 3],
+      [2, 0],
+      [2, 1],
+      [2, 2],
+      [2, 3],
+    ])("should pick the first provider of %d success(es) after %d failure(s)", async (successes, failures) => {
+      const reg = PrometheusProviderRegistry.getInstance();
+      let count = 0;
+
+      for (let i = 0; i < failures; i += 1) {
+        const serviceResult = i % 2 === 0 ? ServiceResult.Failure : ServiceResult.Undefined;
+
+        reg.registerProvider(new TestProvider(`id_${count++}`, serviceResult));
+      }
+
+      for (let i = 0; i < successes; i += 1) {
+        reg.registerProvider(new TestProvider(`id_${count++}`, ServiceResult.Success));
+      }
+
+      const service = await getHandler().getPrometheusService();
+
+      expect(service.id === `id_${failures}`);
+    });
+
+    it.each([
+      [1, 0],
+      [1, 1],
+      [1, 2],
+      [1, 3],
+      [2, 0],
+      [2, 1],
+      [2, 2],
+      [2, 3],
+    ])("should pick the first provider of %d success(es) before %d failure(s)", async (successes, failures) => {
+      const reg = PrometheusProviderRegistry.getInstance();
+      let count = 0;
+
+      for (let i = 0; i < successes; i += 1) {
+        reg.registerProvider(new TestProvider(`id_${count++}`, ServiceResult.Success));
+      }
+
+      for (let i = 0; i < failures; i += 1) {
+        const serviceResult = i % 2 === 0 ? ServiceResult.Failure : ServiceResult.Undefined;
+
+        reg.registerProvider(new TestProvider(`id_${count++}`, serviceResult));
+      }
+
+      const service = await getHandler().getPrometheusService();
+
+      expect(service.id === "id_0");
+    });
+
+    it.each([
+      [1, 0],
+      [1, 1],
+      [1, 2],
+      [1, 3],
+      [2, 0],
+      [2, 1],
+      [2, 2],
+      [2, 3],
+    ])("should pick the first provider of %d success(es) between %d failure(s)", async (successes, failures) => {
+      const reg = PrometheusProviderRegistry.getInstance();
+      let count = 0;
+      const beforeSuccesses = Math.floor(successes / 2);
+      const afterSuccesses = successes - beforeSuccesses;
+
+      for (let i = 0; i < beforeSuccesses; i += 1) {
+        reg.registerProvider(new TestProvider(`id_${count++}`, ServiceResult.Success));
+      }
+
+      for (let i = 0; i < failures; i += 1) {
+        const serviceResult = i % 2 === 0 ? ServiceResult.Failure : ServiceResult.Undefined;
+
+        reg.registerProvider(new TestProvider(`id_${count++}`, serviceResult));
+      }
+
+      for (let i = 0; i < afterSuccesses; i += 1) {
+        reg.registerProvider(new TestProvider(`id_${count++}`, ServiceResult.Success));
+      }
+
+      const service = await getHandler().getPrometheusService();
+
+      expect(service.id === "id_0");
+    });
+
+    it("shouldn't pick the second provider of 2 succcess(es) after 1 failure(s)", async () => {
+      const reg = PrometheusProviderRegistry.getInstance();
+      let count = 0;
+
+      reg.registerProvider(new TestProvider(`id_${count++}`, ServiceResult.Failure));
+      reg.registerProvider(new TestProvider(`id_${count++}`, ServiceResult.Success));
+      reg.registerProvider(new TestProvider(`id_${count++}`, ServiceResult.Success));
+
+      const service = await getHandler().getPrometheusService();
+
+      expect(service.id).not.toBe("id_2");
+    });
+  });
+});