Introduce healthy abstraction between back-end routes and route handlers

Signed-off-by: Janne Savolainen <janne.savolainen@live.fi>

src/main/__test__/router.test.ts

@@ -3,7 +3,7 @@
  * Licensed under MIT License. See LICENSE in root directory for more information.
  */
 
-import type { LensApiRequest } from "../router";
+import type { LensApiRequest, LensApiResult } from "../router";
 import staticFileRouteInjectable from "../routes/static-file-route.injectable";
 import { getDiForUnitTesting } from "../getDiForUnitTesting";
 
@@ -24,7 +24,7 @@ jest.mock("electron", () => ({
 }));
 
 describe("Router", () => {
-  let handleStaticFile: (request: LensApiRequest) => Promise<void>;
+  let handleStaticFile: (request: LensApiRequest) => Promise<LensApiResult>;
 
   beforeEach(async () => {
     const di = getDiForUnitTesting({ doGeneralOverrides: true });

src/main/router.ts

@@ -6,6 +6,8 @@
 import Call from "@hapi/call";
 import Subtext from "@hapi/subtext";
 import type http from "http";
+import type httpProxy from "http-proxy";
+import { toPairs } from "lodash/fp";
 import path from "path";
 import type { Cluster } from "../common/cluster/cluster";
 
@@ -40,6 +42,94 @@ export interface LensApiRequest<P = any> {
   };
 }
 
+const respondFor =
+  (contentType: string) =>
+    (
+      content: any,
+      statusCode: number,
+      response: http.ServerResponse,
+    ) => {
+      response.statusCode = statusCode;
+      response.setHeader("Content-Type", contentType);
+
+      if (content instanceof Buffer) {
+        response.write(content);
+
+        response.end();
+
+        return;
+      }
+
+      response.end(content);
+    };
+
+export type SupportedFileExtension = "json" | "txt" | "html" | "css" | "gif" | "jpg" | "png" | "svg" | "js" | "woff2" | "ttf";
+
+export const contentTypes: Record<SupportedFileExtension, LensApiResultContentType> = {
+  json: {
+    respond: (
+      content: any,
+      statusCode: number,
+      response: http.ServerResponse,
+    ) => {
+      response.statusCode = statusCode;
+      response.setHeader("Content-Type", "application/json");
+
+      if (content instanceof Buffer) {
+        response.write(content);
+        response.end();
+
+        return;
+      }
+
+      const normalizedContent =
+        typeof content === "object" ? JSON.stringify(content) : content;
+
+      response.end(normalizedContent);
+    },
+  },
+
+  txt: {
+    respond: respondFor("text/plain"),
+  },
+
+  html: {
+    respond: respondFor("text/html"),
+  },
+
+  css: {
+    respond: respondFor("text/css"),
+  },
+
+  gif: {
+    respond: respondFor("image/gif"),
+  },
+
+  jpg: {
+    respond: respondFor("image/jpeg"),
+  },
+
+  png: {
+    respond: respondFor("image/png"),
+  },
+
+  svg: {
+    respond: respondFor("image/svg+xml"),
+  },
+
+  js: {
+    respond: respondFor("application/javascript"),
+  },
+
+  woff2: {
+    respond: respondFor("font/woff2"),
+  },
+
+  ttf: {
+    respond: respondFor("font/ttf"),
+  },
+};
+
 export class Router {
   protected router = new Call.Router();
   static rootPath = path.resolve(__static);
@@ -47,7 +137,42 @@ export class Router {
   constructor(routes: Route[]) {
     routes.forEach(route => {
       this.router.add({ method: route.method, path: route.path }, async (request: LensApiRequest) => {
-        await route.handler(request);
+        let result: LensApiResult | void;
+
+        try {
+          result = await route.handler(request);
+        } catch(error) {
+          contentTypes.txt.respond(error.toString(), 422, request.response);
+
+          return;
+        }
+
+        if (!result) {
+          contentTypes.txt.respond(null, 204, request.response);
+
+          return;
+        }
+
+        const {
+          response,
+          error,
+          statusCode = error ? 400 : 200,
+          contentType = contentTypes.json,
+          headers = {},
+          proxy,
+        } = result;
+
+        if (proxy) {
+          return;
+        }
+
+        const headerNameValuePairs = toPairs<string>(headers);
+
+        headerNameValuePairs.forEach(([key, value]) => {
+          request.response.setHeader(key, value);
+        });
+
+        contentType.respond(error || response, statusCode, request.response);
       });
     });
   }
@@ -91,8 +216,21 @@ export class Router {
   }
 }
 
+interface LensApiResultContentType {
+  respond: (content: any, statusCode: number, response: http.ServerResponse) => void;
+}
+
+export interface LensApiResult {
+  statusCode?: number;
+  response?: any;
+  error?: any;
+  contentType?: LensApiResultContentType;
+  headers?: { Location: string };
+  proxy?: httpProxy;
+}
+
 export interface Route {
   path: string;
   method: "get" | "post" | "put" | "patch" | "delete";
-  handler: (request: LensApiRequest) => void | Promise<void>;
+  handler: (request: LensApiRequest) => LensApiResult | Promise<LensApiResult>;
 }

src/main/routes/helm/charts/get-chart-route.injectable.ts

@@ -4,9 +4,8 @@
  */
 import { getInjectable } from "@ogre-tools/injectable";
 import { routeInjectionToken } from "../../../router/router.injectable";
-import type { LensApiRequest } from "../../../router";
+import type { LensApiRequest, LensApiResult } from "../../../router";
 import { helmService } from "../../../helm/helm-service";
-import { respondJson, respondText } from "../../../utils/http-responses";
 import { apiPrefix } from "../../../../common/vars";
 
 const getChartRouteInjectable = getInjectable({
@@ -16,17 +15,16 @@ const getChartRouteInjectable = getInjectable({
     method: "get",
     path: `${apiPrefix}/v2/charts/{repo}/{chart}`,
 
-    handler: async (request: LensApiRequest) => {
-      const { params, query, response } = request;
-
-      try {
-        const chart = await helmService.getChart(params.repo, params.chart, query.get("version"));
-
-        respondJson(response, chart);
-      } catch (error) {
-        respondText(response, error?.toString() || "Error getting chart", 422);
-      }
-    },
+    handler: async ({
+      params,
+      query,
+    }: LensApiRequest): Promise<LensApiResult> => ({
+      response: await helmService.getChart(
+        params.repo,
+        params.chart,
+        query.get("version"),
+      ),
+    }),
   }),
 
   injectionToken: routeInjectionToken,

src/main/routes/helm/charts/get-chart-values-route.injectable.ts

@@ -4,9 +4,8 @@
  */
 import { getInjectable } from "@ogre-tools/injectable";
 import { routeInjectionToken } from "../../../router/router.injectable";
-import type { LensApiRequest } from "../../../router";
+import type { LensApiRequest, LensApiResult } from "../../../router";
 import { helmService } from "../../../helm/helm-service";
-import { respondJson, respondText } from "../../../utils/http-responses";
 import { apiPrefix } from "../../../../common/vars";
 
 const getChartRouteValuesInjectable = getInjectable({
@@ -16,17 +15,16 @@ const getChartRouteValuesInjectable = getInjectable({
     method: "get",
     path: `${apiPrefix}/v2/charts/{repo}/{chart}/values`,
 
-    handler: async (request: LensApiRequest) => {
-      const { params, query, response } = request;
-
-      try {
-        const values = await helmService.getChartValues(params.repo, params.chart, query.get("version"));
-
-        respondJson(response, values);
-      } catch (error) {
-        respondText(response, error?.toString() || "Error getting chart values", 422);
-      }
-    },
+    handler: async ({
+      params,
+      query,
+    }: LensApiRequest): Promise<LensApiResult> => ({
+      response: await helmService.getChartValues(
+        params.repo,
+        params.chart,
+        query.get("version"),
+      ),
+    }),
   }),
 
   injectionToken: routeInjectionToken,

src/main/routes/helm/charts/list-charts-route.injectable.ts

@@ -4,9 +4,8 @@
  */
 import { getInjectable } from "@ogre-tools/injectable";
 import { routeInjectionToken } from "../../../router/router.injectable";
-import type { LensApiRequest } from "../../../router";
+import type { LensApiRequest, LensApiResult } from "../../../router";
 import { helmService } from "../../../helm/helm-service";
-import { respondJson } from "../../../utils/http-responses";
 import { apiPrefix } from "../../../../common/vars";
 
 const listChartsRouteInjectable = getInjectable({
@@ -16,12 +15,10 @@ const listChartsRouteInjectable = getInjectable({
     method: "get",
     path: `${apiPrefix}/v2/charts`,
 
-    handler: async (request: LensApiRequest) => {
-      const { response } = request;
-      const charts = await helmService.listCharts();
-
-      respondJson(response, charts);
-    },
+    // eslint-disable-next-line unused-imports/no-unused-vars-ts
+    handler: async (request: LensApiRequest): Promise<LensApiResult> => ({
+      response: await helmService.listCharts(),
+    }),
   }),
 
   injectionToken: routeInjectionToken,

src/main/routes/helm/releases/delete-release-route.injectable.ts

@@ -3,12 +3,10 @@
  * Licensed under MIT License. See LICENSE in root directory for more information.
  */
 import { apiPrefix } from "../../../../common/vars";
-import type { LensApiRequest } from "../../../router";
+import type { LensApiRequest, LensApiResult } from "../../../router";
 import { helmService } from "../../../helm/helm-service";
-import { respondJson, respondText } from "../../../utils/http-responses";
 import { routeInjectionToken } from "../../../router/router.injectable";
 import { getInjectable } from "@ogre-tools/injectable";
-import logger from "../../../logger";
 
 const deleteReleaseRouteInjectable = getInjectable({
   id: "delete-release-route",
@@ -17,17 +15,16 @@ const deleteReleaseRouteInjectable = getInjectable({
     method: "delete",
     path: `${apiPrefix}/v2/releases/{namespace}/{release}`,
 
-    handler: async (request: LensApiRequest) => {
-      const { cluster, params, response } = request;
+    handler: async (request: LensApiRequest): Promise<LensApiResult> => {
+      const { cluster, params } = request;
 
-      try {
-        const result = await helmService.deleteRelease(cluster, params.release, params.namespace);
-
-        respondJson(response, result);
-      } catch (error) {
-        logger.debug(error);
-        respondText(response, error?.toString() || "Error deleting release", 422);
-      }
+      return {
+        response: await helmService.deleteRelease(
+          cluster,
+          params.release,
+          params.namespace,
+        ),
+      };
     },
   }),
 

src/main/routes/helm/releases/get-release-history-route.injectable.ts

@@ -3,12 +3,10 @@
  * Licensed under MIT License. See LICENSE in root directory for more information.
  */
 import { apiPrefix } from "../../../../common/vars";
-import type { LensApiRequest } from "../../../router";
+import type { LensApiRequest, LensApiResult } from "../../../router";
 import { helmService } from "../../../helm/helm-service";
-import { respondJson, respondText } from "../../../utils/http-responses";
 import { routeInjectionToken } from "../../../router/router.injectable";
 import { getInjectable } from "@ogre-tools/injectable";
-import logger from "../../../logger";
 
 const getReleaseRouteHistoryInjectable = getInjectable({
   id: "get-release-history-route",
@@ -17,17 +15,16 @@ const getReleaseRouteHistoryInjectable = getInjectable({
     method: "get",
     path: `${apiPrefix}/v2/releases/{namespace}/{release}/history`,
 
-    handler: async (request: LensApiRequest) => {
-      const { cluster, params, response } = request;
+    handler: async (request: LensApiRequest): Promise<LensApiResult> => {
+      const { cluster, params } = request;
 
-      try {
-        const result = await helmService.getReleaseHistory(cluster, params.release, params.namespace);
-
-        respondJson(response, result);
-      } catch (error) {
-        logger.debug(error);
-        respondText(response, error?.toString() || "Error getting release history", 422);
-      }
+      return {
+        response: await helmService.getReleaseHistory(
+          cluster,
+          params.release,
+          params.namespace,
+        ),
+      };
     },
   }),
 

src/main/routes/helm/releases/get-release-route.injectable.ts

@@ -3,12 +3,10 @@
  * Licensed under MIT License. See LICENSE in root directory for more information.
  */
 import { apiPrefix } from "../../../../common/vars";
-import type { LensApiRequest } from "../../../router";
+import type { LensApiRequest, LensApiResult } from "../../../router";
 import { helmService } from "../../../helm/helm-service";
-import { respondJson, respondText } from "../../../utils/http-responses";
 import { routeInjectionToken } from "../../../router/router.injectable";
 import { getInjectable } from "@ogre-tools/injectable";
-import logger from "../../../logger";
 
 const getReleaseRouteInjectable = getInjectable({
   id: "get-release-route",
@@ -17,17 +15,16 @@ const getReleaseRouteInjectable = getInjectable({
     method: "get",
     path: `${apiPrefix}/v2/releases/{namespace}/{release}`,
 
-    handler: async (request: LensApiRequest) => {
-      const { cluster, params, response } = request;
+    handler: async (request: LensApiRequest): Promise<LensApiResult> => {
+      const { cluster, params } = request;
 
-      try {
-        const result = await helmService.getRelease(cluster, params.release, params.namespace);
-
-        respondJson(response, result);
-      } catch (error) {
-        logger.debug(error);
-        respondText(response, error?.toString() || "Error getting release", 422);
-      }
+      return {
+        response: await helmService.getRelease(
+          cluster,
+          params.release,
+          params.namespace,
+        ),
+      };
     },
   }),
 

src/main/routes/helm/releases/get-release-values-route.injectable.ts

@@ -3,13 +3,12 @@
  * Licensed under MIT License. See LICENSE in root directory for more information.
  */
 import { apiPrefix } from "../../../../common/vars";
-import type { LensApiRequest } from "../../../router";
+import type { LensApiRequest, LensApiResult } from "../../../router";
 import { helmService } from "../../../helm/helm-service";
-import { respondText } from "../../../utils/http-responses";
 import { routeInjectionToken } from "../../../router/router.injectable";
 import { getInjectable } from "@ogre-tools/injectable";
-import logger from "../../../logger";
 import { getBoolean } from "../../../utils/parse-query";
+import { contentTypes } from "../../../router";
 
 const getReleaseRouteValuesInjectable = getInjectable({
   id: "get-release-values-route",
@@ -18,18 +17,19 @@ const getReleaseRouteValuesInjectable = getInjectable({
     method: "get",
     path: `${apiPrefix}/v2/releases/{namespace}/{release}/values`,
 
-    handler: async (request: LensApiRequest) => {
-      const { cluster, params: { namespace, release }, response, query } = request;
+    handler: async (request: LensApiRequest): Promise<LensApiResult> => {
+      const { cluster, params: { namespace, release }, query } = request;
       const all = getBoolean(query, "all");
 
-      try {
-        const result = await helmService.getReleaseValues(release, { cluster, namespace, all });
+      return {
+        response: await helmService.getReleaseValues(release, {
+          cluster,
+          namespace,
+          all,
+        }),
 
-        respondText(response, result);
-      } catch (error) {
-        logger.debug(error);
-        respondText(response, error?.toString() || "Error getting release values", 422);
-      }
+        contentType: contentTypes.txt,
+      };
     },
   }),
 

src/main/routes/helm/releases/install-chart-route.injectable.ts

@@ -3,12 +3,10 @@
  * Licensed under MIT License. See LICENSE in root directory for more information.
  */
 import { apiPrefix } from "../../../../common/vars";
-import type { LensApiRequest } from "../../../router";
+import type { LensApiRequest, LensApiResult } from "../../../router";
 import { helmService } from "../../../helm/helm-service";
-import { respondJson, respondText } from "../../../utils/http-responses";
 import { routeInjectionToken } from "../../../router/router.injectable";
 import { getInjectable } from "@ogre-tools/injectable";
-import logger from "../../../logger";
 
 const installChartRouteInjectable = getInjectable({
   id: "install-chart-route",
@@ -17,17 +15,13 @@ const installChartRouteInjectable = getInjectable({
     method: "post",
     path: `${apiPrefix}/v2/releases`,
 
-    handler: async (request: LensApiRequest) => {
-      const { payload, cluster, response } = request;
+    handler: async (request: LensApiRequest): Promise<LensApiResult> => {
+      const { payload, cluster } = request;
 
-      try {
-        const result = await helmService.installChart(cluster, payload);
-
-        respondJson(response, result, 201);
-      } catch (error) {
-        logger.debug(error);
-        respondText(response, error?.toString() || "Error installing chart", 422);
-      }
+      return {
+        response: await helmService.installChart(cluster, payload),
+        statusCode: 201,
+      };
     },
   }),
 

src/main/routes/helm/releases/list-releases-route.injectable.ts

@@ -3,12 +3,10 @@
  * Licensed under MIT License. See LICENSE in root directory for more information.
  */
 import { apiPrefix } from "../../../../common/vars";
-import type { LensApiRequest } from "../../../router";
+import type { LensApiRequest, LensApiResult } from "../../../router";
 import { helmService } from "../../../helm/helm-service";
-import { respondJson, respondText } from "../../../utils/http-responses";
 import { routeInjectionToken } from "../../../router/router.injectable";
 import { getInjectable } from "@ogre-tools/injectable";
-import logger from "../../../logger";
 
 const listReleasesRouteInjectable = getInjectable({
   id: "list-releases-route",
@@ -17,17 +15,12 @@ const listReleasesRouteInjectable = getInjectable({
     method: "get",
     path: `${apiPrefix}/v2/releases/{namespace?}`,
 
-    handler: async (request: LensApiRequest) => {
-      const { cluster, params, response } = request;
+    handler: async (request: LensApiRequest): Promise<LensApiResult> => {
+      const { cluster, params } = request;
 
-      try {
-        const result = await helmService.listReleases(cluster, params.namespace);
-
-        respondJson(response, result);
-      } catch(error) {
-        logger.debug(error);
-        respondText(response, error?.toString() || "Error listing release", 422);
-      }
+      return {
+        response: await helmService.listReleases(cluster, params.namespace),
+      };
     },
   }),
 

src/main/routes/helm/releases/rollback-release-route.injectable.ts

@@ -5,10 +5,8 @@
 import { apiPrefix } from "../../../../common/vars";
 import type { LensApiRequest } from "../../../router";
 import { helmService } from "../../../helm/helm-service";
-import { respondText } from "../../../utils/http-responses";
 import { routeInjectionToken } from "../../../router/router.injectable";
 import { getInjectable } from "@ogre-tools/injectable";
-import logger from "../../../logger";
 
 const rollbackReleaseRouteInjectable = getInjectable({
   id: "rollback-release-route",
@@ -17,20 +15,14 @@ const rollbackReleaseRouteInjectable = getInjectable({
     method: "put",
     path: `${apiPrefix}/v2/releases/{namespace}/{release}/rollback`,
 
-    handler: async (request: LensApiRequest) => {
-      const { cluster, params, payload, response } = request;
+    handler: async (request: LensApiRequest): Promise<void> => {
+      const { cluster, params, payload } = request;
 
-      try {
-        await helmService.rollback(cluster, params.release, params.namespace, payload.revision);
-
-        response.end();
-      } catch (error) {
-        logger.debug(error);
-        respondText(response, error?.toString() || "Error rolling back chart", 422);
-      }
+      await helmService.rollback(cluster, params.release, params.namespace, payload.revision);
     },
   }),
 
+  // @ts-ignore
   injectionToken: routeInjectionToken,
 });
 

src/main/routes/helm/releases/update-release-route.injectable.ts

@@ -3,12 +3,10 @@
  * Licensed under MIT License. See LICENSE in root directory for more information.
  */
 import { apiPrefix } from "../../../../common/vars";
-import type { LensApiRequest } from "../../../router";
+import type { LensApiRequest, LensApiResult } from "../../../router";
 import { helmService } from "../../../helm/helm-service";
-import { respondJson, respondText } from "../../../utils/http-responses";
 import { routeInjectionToken } from "../../../router/router.injectable";
 import { getInjectable } from "@ogre-tools/injectable";
-import logger from "../../../logger";
 
 const updateReleaseRouteInjectable = getInjectable({
   id: "update-release-route",
@@ -17,18 +15,18 @@ const updateReleaseRouteInjectable = getInjectable({
     method: "put",
     path: `${apiPrefix}/v2/releases/{namespace}/{release}`,
 
-    handler: async (request: LensApiRequest) => {
-      const { cluster, params, payload, response } = request;
-
-      try {
-        const result = await helmService.updateRelease(cluster, params.release, params.namespace, payload );
-
-        respondJson(response, result);
-      } catch (error) {
-        logger.debug(error);
-        respondText(response, error?.toString() || "Error updating chart", 422);
-      }
-    },
+    handler: async ({
+      cluster,
+      params,
+      payload,
+    }: LensApiRequest): Promise<LensApiResult> => ({
+      response: await helmService.updateRelease(
+        cluster,
+        params.release,
+        params.namespace,
+        payload,
+      ),
+    }),
   }),
 
   injectionToken: routeInjectionToken,

src/main/routes/kubeconfig-route/get-service-account-route.injectable.ts

@@ -5,13 +5,11 @@
 
 import { getInjectable } from "@ogre-tools/injectable";
 import { apiPrefix } from "../../../common/vars";
-import type { LensApiRequest } from "../../router";
-import { respondJson } from "../../utils/http-responses";
+import type { LensApiRequest, LensApiResult } from "../../router";
 import { routeInjectionToken } from "../../router/router.injectable";
 import type { Cluster } from "../../../common/cluster/cluster";
 import { CoreV1Api, V1Secret } from "@kubernetes/client-node";
 
-
 const getServiceAccountRouteInjectable = getInjectable({
   id: "get-service-account-route",
 
@@ -19,8 +17,8 @@ const getServiceAccountRouteInjectable = getInjectable({
     method: "get",
     path: `${apiPrefix}/kubeconfig/service-account/{namespace}/{account}`,
 
-    handler: async (request: LensApiRequest) => {
-      const { params, response, cluster } = request;
+    handler: async (request: LensApiRequest): Promise<LensApiResult> => {
+      const { params, cluster } = request;
       const client = (await cluster.getProxyKubeconfig()).makeApiClient(CoreV1Api);
       const secretList = await client.listNamespacedSecret(params.namespace);
 
@@ -30,9 +28,7 @@ const getServiceAccountRouteInjectable = getInjectable({
         return annotations && annotations["kubernetes.io/service-account.name"] == params.account;
       });
 
-      const data = generateKubeConfig(params.account, secret, cluster);
-
-      respondJson(response, data);
+      return { response: generateKubeConfig(params.account, secret, cluster) };
     },
   }),
 

src/main/routes/metrics/add-metrics-route.injectable.ts

@@ -5,8 +5,7 @@
 
 import { getInjectable } from "@ogre-tools/injectable";
 import { apiPrefix } from "../../../common/vars";
-import type { LensApiRequest } from "../../router";
-import { respondJson } from "../../utils/http-responses";
+import type { LensApiRequest, LensApiResult } from "../../router";
 import { routeInjectionToken } from "../../router/router.injectable";
 import { ClusterMetadataKey, ClusterPrometheusMetadata } from "../../../common/cluster-types";
 import logger from "../../logger";
@@ -43,7 +42,7 @@ async function loadMetrics(promQueries: string[], cluster: Cluster, prometheusPa
   return Promise.all(queries.map(loadMetric));
 }
 
-const addMetricsRoute = async ({ response, cluster, payload, query }: LensApiRequest) => {
+const addMetricsRoute = async ({ cluster, payload, query }: LensApiRequest): Promise<LensApiResult> => {
   const queryParams: IMetricsQuery = Object.fromEntries(query.entries());
   const prometheusMetadata: ClusterPrometheusMetadata = {};
 
@@ -56,33 +55,39 @@ const addMetricsRoute = async ({ response, cluster, payload, query }: LensApiReq
     if (!prometheusPath) {
       prometheusMetadata.success = false;
 
-      return respondJson(response, {});
+      return { response: {}};
     }
 
     // return data in same structure as query
     if (typeof payload === "string") {
       const [data] = await loadMetrics([payload], cluster, prometheusPath, queryParams);
 
-      respondJson(response, data);
-    } else if (Array.isArray(payload)) {
+      return { response: data };
+    }
+
+    if (Array.isArray(payload)) {
       const data = await loadMetrics(payload, cluster, prometheusPath, queryParams);
 
-      respondJson(response, data);
-    } else {
-      const queries = Object.entries<Record<string, string>>(payload)
-        .map(([queryName, queryOpts]) => (
-          provider.getQuery(queryOpts, queryName)
-        ));
-      const result = await loadMetrics(queries, cluster, prometheusPath, queryParams);
-      const data = Object.fromEntries(Object.keys(payload).map((metricName, i) => [metricName, result[i]]));
-
-      respondJson(response, data);
+      return { response: data };
     }
+
+    const queries = Object.entries<Record<string, string>>(payload)
+      .map(([queryName, queryOpts]) => (
+        provider.getQuery(queryOpts, queryName)
+      ));
+
+    const result = await loadMetrics(queries, cluster, prometheusPath, queryParams);
+    const data = Object.fromEntries(Object.keys(payload).map((metricName, i) => [metricName, result[i]]));
+
     prometheusMetadata.success = true;
+
+    return { response: data };
   } catch (error) {
     prometheusMetadata.success = false;
-    respondJson(response, {});
+
     logger.warn(`[METRICS-ROUTE]: failed to get metrics for clusterId=${cluster.id}:`, error);
+
+    return { response: {}};
   } finally {
     cluster.metadata[ClusterMetadataKey.PROMETHEUS] = prometheusMetadata;
   }

src/main/routes/metrics/get-metric-providers-route.injectable.ts

@@ -5,8 +5,7 @@
 
 import { getInjectable } from "@ogre-tools/injectable";
 import { apiPrefix } from "../../../common/vars";
-import type { LensApiRequest } from "../../router";
-import { respondJson } from "../../utils/http-responses";
+import type { LensApiRequest, LensApiResult } from "../../router";
 import { routeInjectionToken } from "../../router/router.injectable";
 import { PrometheusProviderRegistry } from "../../prometheus";
 import type { MetricProviderInfo } from "../../../common/k8s-api/endpoints/metrics.api";
@@ -18,14 +17,15 @@ const getMetricProvidersRouteInjectable = getInjectable({
     method: "get",
     path: `${apiPrefix}/metrics/providers`,
 
-    handler: async (request: LensApiRequest) => {
+    // eslint-disable-next-line unused-imports/no-unused-vars-ts
+    handler: async (request: LensApiRequest) : Promise<LensApiResult> => {
       const providers: MetricProviderInfo[] = [];
 
       for (const { name, id, isConfigurable } of PrometheusProviderRegistry.getInstance().providers.values()) {
         providers.push({ name, id, isConfigurable });
       }
 
-      respondJson(request.response, providers);
+      return { response: providers };
     },
   }),
 

src/main/routes/port-forward/get-current-port-forward-route.injectable.ts

@@ -4,13 +4,12 @@
  */
 import { getInjectable } from "@ogre-tools/injectable";
 import { routeInjectionToken } from "../../router/router.injectable";
-import type { LensApiRequest } from "../../router";
+import type { LensApiRequest, LensApiResult } from "../../router";
 import { apiPrefix } from "../../../common/vars";
-import { respondJson } from "../../utils/http-responses";
 import { PortForward } from "./functionality/port-forward";
 
-const getCurrentPortForward = async (request: LensApiRequest) => {
-  const { params, query, response, cluster } = request;
+const getCurrentPortForward = async (request: LensApiRequest): Promise<LensApiResult> => {
+  const { params, query, cluster } = request;
   const { namespace, resourceType, resourceName } = params;
   const port = Number(query.get("port"));
   const forwardPort = Number(query.get("forwardPort"));
@@ -20,7 +19,7 @@ const getCurrentPortForward = async (request: LensApiRequest) => {
     namespace, port, forwardPort,
   });
 
-  respondJson(response, { port: portForward?.forwardPort ?? null });
+  return { response: { port: portForward?.forwardPort ?? null }};
 };
 
 const getCurrentPortForwardRouteInjectable = getInjectable({

src/main/routes/port-forward/start-port-forward-route.injectable.ts

@@ -4,19 +4,18 @@
  */
 import { getInjectable } from "@ogre-tools/injectable";
 import { routeInjectionToken } from "../../router/router.injectable";
-import type { LensApiRequest } from "../../router";
+import type { LensApiRequest, LensApiResult } from "../../router";
 import { apiPrefix } from "../../../common/vars";
 import { PortForward, PortForwardArgs } from "./functionality/port-forward";
 import logger from "../../logger";
-import { respondJson } from "../../utils/http-responses";
 import createPortForwardInjectable from "./functionality/create-port-forward.injectable";
 
 interface Dependencies {
   createPortForward: (pathToKubeConfig: string, args: PortForwardArgs) => PortForward;
 }
 
-const startPortForward = ({ createPortForward }: Dependencies) => async (request: LensApiRequest) => {
-  const { params, query, response, cluster } = request;
+const startPortForward = ({ createPortForward }: Dependencies) => async (request: LensApiRequest): Promise<LensApiResult> => {
+  const { params, query, cluster } = request;
   const { namespace, resourceType, resourceName } = params;
   const port = Number(query.get("port"));
   const forwardPort = Number(query.get("forwardPort"));
@@ -58,32 +57,28 @@ const startPortForward = ({ createPortForward }: Dependencies) => async (request
           resourceName,
         });
 
-        return respondJson(
-          response,
-          {
+        return {
+          error: {
             message: `Failed to forward port ${port} to ${
               thePort ? forwardPort : "random port"
             }`,
           },
-          400,
-        );
+        };
       }
     }
 
-    respondJson(response, { port: portForward.forwardPort });
+    return { response: { port: portForward.forwardPort }};
   } catch (error) {
     logger.error(
       `[PORT-FORWARD-ROUTE]: failed to open a port-forward: ${error}`,
       { namespace, port, resourceType, resourceName },
     );
 
-    return respondJson(
-      response,
-      {
+    return {
+      error: {
         message: `Failed to forward port ${port}`,
       },
-      400,
-    );
+    };
   }
 };
 

src/main/routes/port-forward/stop-current-port-forward-route.injectable.ts

@@ -4,14 +4,13 @@
  */
 import { getInjectable } from "@ogre-tools/injectable";
 import { routeInjectionToken } from "../../router/router.injectable";
-import type { LensApiRequest } from "../../router";
+import type { LensApiRequest, LensApiResult } from "../../router";
 import { apiPrefix } from "../../../common/vars";
-import { respondJson } from "../../utils/http-responses";
 import { PortForward } from "./functionality/port-forward";
 import logger from "../../logger";
 
-const stopCurrentPortForward = async (request: LensApiRequest) => {
-  const { params, query, response, cluster } = request;
+const stopCurrentPortForward = async (request: LensApiRequest): Promise<LensApiResult> => {
+  const { params, query, cluster } = request;
   const { namespace, resourceType, resourceName } = params;
   const port = Number(query.get("port"));
   const forwardPort = Number(query.get("forwardPort"));
@@ -23,13 +22,17 @@ const stopCurrentPortForward = async (request: LensApiRequest) => {
 
   try {
     await portForward.stop();
-    respondJson(response, { status: true });
+
+    return { response: { status: true }};
   } catch (error) {
     logger.error("[PORT-FORWARD-ROUTE]: error stopping a port-forward", { namespace, port, forwardPort, resourceType, resourceName });
 
-    return respondJson(response, {
-      message: `error stopping a forward port ${port}`,
-    }, 400);
+    return {
+      error: {
+        message: `error stopping a forward port ${port}`,
+      },
+    };
+
   }
 };
 

src/main/routes/resource-applier/apply-resource-route.injectable.ts

@@ -4,10 +4,9 @@
  */
 import { getInjectable } from "@ogre-tools/injectable";
 import { routeInjectionToken } from "../../router/router.injectable";
-import type { LensApiRequest } from "../../router";
+import type { LensApiRequest, LensApiResult } from "../../router";
 import { apiPrefix } from "../../../common/vars";
 import { ResourceApplier } from "../../resource-applier";
-import { respondJson, respondText } from "../../utils/http-responses";
 
 const applyResourceRouteInjectable = getInjectable({
   id: "apply-resource-route",
@@ -16,17 +15,12 @@ const applyResourceRouteInjectable = getInjectable({
     method: "post",
     path: `${apiPrefix}/stack`,
 
-    handler: async (request: LensApiRequest) => {
-      const { response, cluster, payload } = request;
-
-      try {
-        const resource = await new ResourceApplier(cluster).apply(payload);
-
-        respondJson(response, resource, 200);
-      } catch (error) {
-        respondText(response, error, 422);
-      }
-    },
+    handler: async ({
+      cluster,
+      payload,
+    }: LensApiRequest): Promise<LensApiResult> => ({
+      response: await new ResourceApplier(cluster).apply(payload),
+    }),
   }),
 
   injectionToken: routeInjectionToken,

src/main/routes/resource-applier/patch-resource-route.injectable.ts

@@ -4,10 +4,9 @@
  */
 import { getInjectable } from "@ogre-tools/injectable";
 import { routeInjectionToken } from "../../router/router.injectable";
-import type { LensApiRequest } from "../../router";
+import type { LensApiRequest, LensApiResult } from "../../router";
 import { apiPrefix } from "../../../common/vars";
 import { ResourceApplier } from "../../resource-applier";
-import { respondJson, respondText } from "../../utils/http-responses";
 
 const patchResourceRouteInjectable = getInjectable({
   id: "patch-resource-route",
@@ -16,17 +15,17 @@ const patchResourceRouteInjectable = getInjectable({
     method: "patch",
     path: `${apiPrefix}/stack`,
 
-    handler: async (request: LensApiRequest) => {
-      const { response, cluster, payload } = request;
-
-      try {
-        const resource = await new ResourceApplier(cluster).patch(payload.name, payload.kind, payload.patch, payload.ns);
-
-        respondJson(response, resource, 200);
-      } catch (error) {
-        respondText(response, error, 422);
-      }
-    },
+    handler: async ({
+      cluster,
+      payload,
+    }: LensApiRequest): Promise<LensApiResult> => ({
+      response: await new ResourceApplier(cluster).patch(
+        payload.name,
+        payload.kind,
+        payload.patch,
+        payload.ns,
+      ),
+    }),
   }),
 
   injectionToken: routeInjectionToken,

src/main/routes/static-file-route.injectable.ts

@@ -3,35 +3,15 @@
  * Licensed under MIT License. See LICENSE in root directory for more information.
  */
 import { getInjectable } from "@ogre-tools/injectable";
-import type { LensApiRequest, Route } from "../router";
+import type { LensApiRequest, LensApiResult, SupportedFileExtension, Route } from "../router";
+import { contentTypes } from "../router";
 import logger from "../logger";
 import { routeInjectionToken } from "../router/router.injectable";
-import {
-  appName,
-  publicPath,
-} from "../../common/vars";
+import { appName, publicPath } from "../../common/vars";
 import path from "path";
 import readFileInjectable from "../../common/fs/read-file.injectable";
 import isDevelopmentInjectable from "../../common/vars/is-development.injectable";
 import httpProxy from "http-proxy";
-import { Router } from "../router";
-
-function getMimeType(filename: string) {
-  const mimeTypes: Record<string, string> = {
-    html: "text/html",
-    txt: "text/plain",
-    css: "text/css",
-    gif: "image/gif",
-    jpg: "image/jpeg",
-    png: "image/png",
-    svg: "image/svg+xml",
-    js: "application/javascript",
-    woff2: "font/woff2",
-    ttf: "font/ttf",
-  };
-
-  return mimeTypes[path.extname(filename).slice(1)] || "text/plain";
-}
 
 interface ProductionDependencies {
   readFile: (path: string) => Promise<Buffer>;
@@ -39,36 +19,38 @@ interface ProductionDependencies {
 
 const handleStaticFileInProduction =
   ({ readFile }: ProductionDependencies) =>
-    async ({ params, response }: LensApiRequest): Promise<void> => {
+    async ({ params }: LensApiRequest): Promise<LensApiResult> => {
+      const staticPath = path.resolve(__static);
       let filePath = params.path;
 
       for (let retryCount = 0; retryCount < 5; retryCount += 1) {
-        const asset = path.join(Router.rootPath, filePath);
+        const asset = path.join(staticPath, filePath);
         const normalizedFilePath = path.resolve(asset);
 
-        if (!normalizedFilePath.startsWith(Router.rootPath)) {
-          response.statusCode = 404;
-
-          return response.end();
+        if (!normalizedFilePath.startsWith(staticPath)) {
+          return { statusCode: 404 };
         }
 
         try {
-          const data = await readFile(asset);
+          const fileExtension = path
+            .extname(asset)
+            .slice(1) as SupportedFileExtension;
 
-          response.setHeader("Content-Type", getMimeType(asset));
-          response.write(data);
-          response.end();
+          const contentType = contentTypes[fileExtension] || contentTypes.txt;
+
+          return { response: await readFile(asset), contentType };
         } catch (err) {
           if (retryCount > 5) {
             logger.error("handleStaticFile:", err.toString());
-            response.statusCode = 404;
 
-            return response.end();
+            return { statusCode: 404 };
           }
 
           filePath = `${publicPath}/${appName}.html`;
         }
       }
+
+      return { statusCode: 404 };
     };
 
 interface DevelopmentDependencies {
@@ -87,6 +69,8 @@ const handleStaticFileInDevelopment =
       proxy.web(req, res, {
         target: "http://127.0.0.1:8080",
       });
+
+      return { proxy };
     };
 
 const staticFileRouteInjectable = getInjectable({

src/main/routes/versions/get-version-route.injectable.ts

@@ -3,8 +3,7 @@
  * Licensed under MIT License. See LICENSE in root directory for more information.
  */
 import { getInjectable } from "@ogre-tools/injectable";
-import type { LensApiRequest } from "../../router";
-import { respondJson } from "../../utils/http-responses";
+import type { LensApiRequest, LensApiResult } from "../../router";
 import { routeInjectionToken } from "../../router/router.injectable";
 import { getAppVersion } from "../../../common/utils";
 
@@ -15,10 +14,9 @@ const getVersionRouteInjectable = getInjectable({
     method: "get",
     path: `/version`,
 
-    handler: async (request: LensApiRequest) => {
-      const { response } = request;
-
-      respondJson(response, { version: getAppVersion() }, 200);
+    // eslint-disable-next-line unused-imports/no-unused-vars-ts
+    handler: async (request: LensApiRequest): Promise<LensApiResult> => {
+      return { response: { version: getAppVersion() }};
     },
   }),