Use typed Koa context

.changeset/clean-cats-dream.md

@@ -0,0 +1,5 @@
+---
+'skuba': patch
+---
+
+**template/koa-rest-api:** Type context

template/koa-rest-api/src/api/healthCheck.ts

@@ -1,4 +1,4 @@
-import { Middleware } from 'koa';
+import { Middleware } from 'src/types/koa';
 
 export const healthCheckHandler: Middleware = (ctx) => {
   ctx.state.skipRequestLogging = true;

template/koa-rest-api/src/api/jobs/getJobs.ts

@@ -1,8 +1,7 @@
-import { Middleware } from 'koa';
-
 import { contextLogger } from 'src/framework/logging';
 import { metricsClient } from 'src/framework/metrics';
 import * as storage from 'src/storage/jobs';
+import { Middleware } from 'src/types/koa';
 
 export const getJobsHandler: Middleware = async (ctx) => {
   const jobs = await storage.readJobs();

template/koa-rest-api/src/api/jobs/postJob.ts

@@ -1,10 +1,9 @@
-import { Middleware } from 'koa';
-
 import { contextLogger } from 'src/framework/logging';
 import { metricsClient } from 'src/framework/metrics';
 import { validateRequestBody } from 'src/framework/validation';
 import * as storage from 'src/storage/jobs';
 import { filterJobInput } from 'src/types/jobs';
+import { Middleware } from 'src/types/koa';
 
 export const postJobHandler: Middleware = async (ctx) => {
   const jobInput = validateRequestBody(ctx, filterJobInput);

template/koa-rest-api/src/api/smokeTest.ts

@@ -1,3 +1,3 @@
-import { Middleware } from 'koa';
+import { Middleware } from 'src/types/koa';
 
 export const smokeTestHandler: Middleware = (ctx) => (ctx.body = '');

template/koa-rest-api/src/framework/logging.ts

@@ -1,8 +1,8 @@
 import createLogger from '@seek/logger';
-import { Context } from 'koa';
 import { RequestLogging } from 'seek-koala';
 
 import { config } from 'src/config';
+import { Context } from 'src/types/koa';
 
 export const rootLogger = createLogger({
   base: {

template/koa-rest-api/src/framework/server.test.ts

@@ -1,10 +1,10 @@
 import Router from '@koa/router';
-import { Middleware } from 'koa';
 
 import { rootLogger } from 'src/testing/logging';
 import { metricsClient } from 'src/testing/metrics';
 import { agentFromRouter } from 'src/testing/server';
 import { chance } from 'src/testing/types';
+import { Middleware } from 'src/types/koa';
 
 const middleware = jest.fn<void, Parameters<Middleware>>();
 

template/koa-rest-api/src/framework/server.ts

@@ -1,4 +1,4 @@
-import Koa, { Context, DefaultState, Middleware } from 'koa';
+import Koa from 'koa';
 import compose from 'koa-compose';
 import {
   ErrorMiddleware,
@@ -18,25 +18,25 @@ const metrics = MetricsMiddleware.create(
   }),
 );
 
-const requestLogging = RequestLogging.createMiddleware<DefaultState, Context>(
-  (ctx, fields, err) => {
-    if (typeof err === 'undefined') {
-      // Depend on sidecar logging for happy path requests
-      return;
-    }
+const requestLogging = RequestLogging.createMiddleware((ctx, fields, err) => {
+  if (typeof err === 'undefined') {
+    // Depend on sidecar logging for happy path requests
+    return;
+  }
 
-    return ctx.status < 500
-      ? rootLogger.info(fields, 'Client error')
-      : rootLogger.error(fields, 'Server error');
-  },
-);
+  return ctx.status < 500
+    ? rootLogger.info(fields, 'Client error')
+    : rootLogger.error(fields, 'Server error');
+});
 
 const version = VersionMiddleware.create({
   name: config.name,
   version: config.version,
 });
 
-export const createApp = <S, C>(...middleware: Middleware<S, C>[]) =>
+export const createApp = <State, Context>(
+  ...middleware: Koa.Middleware<State, Context>[]
+) =>
   new Koa()
     .use(requestLogging)
     .use(metrics)

template/koa-rest-api/src/framework/validation.ts

@@ -1,4 +1,4 @@
-import { Context } from 'koa';
+import { Context } from 'src/types/koa';
 
 export const validate = <T>({
   ctx,

template/koa-rest-api/src/testing/server.ts

@@ -1,5 +1,5 @@
 import Router from '@koa/router';
-import Koa, { Middleware } from 'koa';
+import Koa from 'koa';
 import request from 'supertest';
 
 import { createApp } from 'src/framework/server';
@@ -14,7 +14,7 @@ export const agentFromApp = <State, Context>(app: Koa<State, Context>) =>
  * Create a new SuperTest agent from a set of Koa middleware.
  */
 export const agentFromMiddleware = <State, Context>(
-  ...middleware: Middleware<State, Context>[]
+  ...middleware: Koa.Middleware<State, Context>[]
 ) => {
   const app = createApp(...middleware);
 

template/koa-rest-api/src/types/koa.ts

@@ -0,0 +1,9 @@
+import Koa from 'koa';
+
+export type Context = Koa.ParameterizedContext<State>;
+
+export type Middleware = Koa.Middleware<State>;
+
+export interface State {
+  skipRequestLogging?: boolean;
+}