add client template

Signed-off-by: Ryan Vazquez <ryanv@spotify.com>

.changeset/short-schools-pay.md

@@ -0,0 +1,5 @@
+---
+'@backstage/plugin-cost-insights': patch
+---
+
+Added example client

plugins/cost-insights/README.md

@@ -25,9 +25,7 @@ yarn add @backstage/plugin-cost-insights
 
 1. Configure `app-config.yaml`. See [Configuration](#configuration).
 
-2. Create a CostInsights client. Clients must implement the CostInsightsApi interface. See the [API file](https://github.com/backstage/backstage/blob/master/plugins/cost-insights/src/api/CostInsightsApi.ts) for required methods and documentation.
-
-**Note:** We've briefly explored using the AWS Cost Explorer API to implement a CostInsights client. Learn more about our findings [here](https://github.com/backstage/backstage/blob/master/plugins/cost-insights/contrib/aws-cost-explorer-api.md).
+2. Create a CostInsights client. Clients must implement the [CostInsightsApi](https://github.com/backstage/backstage/blob/master/plugins/cost-insights/src/api/CostInsightsApi.ts) interface. Create your own or [use a template](https://github.com/backstage/backstage/blob/master/plugins/cost-insights/src/example/templates/CostInsightsClient.ts) to get started.
 
 ```ts
 // path/to/CostInsightsClient.ts
@@ -36,7 +34,9 @@ import { CostInsightsApi } from '@backstage/plugin-cost-insights';
 export class CostInsightsClient implements CostInsightsApi { ... }
 ```
 
-3. Import the client and the CostInsights plugin API to your Backstage instance.
+**Note:** We've briefly explored using the AWS Cost Explorer API to implement a Cost Insights client. Learn more about our findings [here](https://github.com/backstage/backstage/blob/master/plugins/cost-insights/contrib/aws-cost-explorer-api.md).
+
+3. Import the client and the Cost Insights plugin API to your Backstage instance.
 
 ```ts
 // packages/app/src/api.ts

plugins/cost-insights/src/example/templates/CostInsightsClient.ts

@@ -0,0 +1,101 @@
+/*
+ * Copyright 2020 Spotify AB
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/*
+  This is a copy-pastable client template to get up and running quickly.
+  API Reference:
+  https://github.com/backstage/backstage/blob/master/plugins/cost-insights/src/api/CostInsightsApi.ts
+*/
+
+// IMPORTANT: Remove the lines below to enable type checking and linting
+// @ts-nocheck
+/* eslint-disable import/no-extraneous-dependencies */
+
+import {
+  CostInsightsApi,
+  ProductInsightsOptions,
+  Alert,
+  Cost,
+  Entity,
+  Group,
+  MetricData,
+  Project,
+} from '@backstage/plugin-cost-insights';
+
+export class CostInsightsClient implements CostInsightsApi {
+
+  async getLastCompleteBillingDate(): Promise<string> {
+    return '2021-01-01'; // YYYY-MM-DD
+  }
+
+  async getUserGroups(userId: string): Promise<Group[]> {
+    return [];
+  }
+
+  async getGroupProjects(group: string): Promise<Project[]> {
+    return [];
+  }
+
+  async getAlerts(group: string): Promise<Alert[]> {
+    return [];
+  }
+
+  async getDailyMetricData(metric: string, intervals: string): Promise<MetricData> {
+    return {
+      id: 'remove-me',
+      format: 'number',
+      aggregation: [],
+      change: {
+        ratio: 0,
+        amount: 0
+      }
+    }
+  }
+
+  async getGroupDailyCost(group: string, intervals: string): Promise<Cost> {
+    return {
+      id: 'remove-me',
+      aggregation: [],
+      change: {
+        ratio: 0,
+        amount: 0
+      }
+    }
+  }
+
+  async getProjectDailyCost(project: string, intervals: string): Promise<Cost> {
+    return {
+      id: 'remove-me',
+      aggregation: [],
+      change: {
+        ratio: 0,
+        amount: 0
+      }
+    }
+  }
+
+  async getProductInsights(options: ProductInsightsOptions): Promise<Entity> {
+    return {
+      id: 'remove-me',
+      aggregation: [0, 0],
+      change: {
+        ratio: 0,
+        amount: 0
+      },
+      entities: {}
+    }
+  }
+}