ci: run a server smoke test in the pipeline

This verifies the server can launch with all the default settings.

.github/workflows/main.yml

@@ -10,6 +10,7 @@ jobs:
   lint:
     runs-on: ubuntu-latest
     name: Lint
+    timeout-minutes: 5
 
     steps:
       - uses: actions/checkout@v2
@@ -27,6 +28,7 @@ jobs:
   unit_test:
     runs-on: ubuntu-latest
     name: Unit Test
+    timeout-minutes: 5
 
     steps:
       - uses: actions/checkout@v2
@@ -41,9 +43,28 @@ jobs:
       - run: yarn install
       - run: yarn test
 
+  smoke_test:
+    runs-on: ubuntu-latest
+    name: Smoke Test
+    timeout-minutes: 5
+
+    steps:
+      - uses: actions/checkout@v2
+      - name: Get yarn cache directory path
+        id: yarn-cache-dir-path
+        run: echo "::set-output name=dir::$(yarn cache dir)"
+      - uses: actions/cache@v1
+        with:
+          path: ${{ steps.yarn-cache-dir-path.outputs.dir }}
+          key: ${{ runner.os }}-yarn-${{ hashFiles('yarn.lock') }}
+          restore-keys: ${{ runner.os }}-yarn-
+      - run: yarn install
+      - run: scripts/smoke-test
+
   integration_test:
     runs-on: ubuntu-latest
     name: Integration Test
+    timeout-minutes: 5
 
     steps:
       - uses: actions/checkout@v2

scripts/smoke-test

@@ -0,0 +1,30 @@
+#!/bin/bash
+
+# This script launches the Cognito Local server, then polls the server until the /health endpoint
+# responds with a 200. If the server doesn't respond in time, or exits with a non-zero code, the
+# script will fail.
+#
+# We run this in CI to prove the actual server can start. This catches some edge-cases where
+# everything else passes, but something in the compile produced invalid JavaScript.
+
+export PORT=59232
+yarn start &
+PID=$!
+
+trap "kill $PID" SIGINT
+
+PORT=$PORT timeout --foreground -s TERM 30 bash -c \
+'while [[ ${STATUS_RECEIVED} != 200 ]];\
+  do STATUS_RECEIVED=$(curl -s -o /dev/null -L -w ''%{http_code}'' http://localhost:$PORT/health) && \
+  echo "received status: $STATUS_RECEIVED" && \
+  sleep 1;\
+done;
+echo success with status: $STATUS_RECEIVED'
+CURL_EXIT_CODE=$?
+
+kill $PID
+
+if [[ $CURL_EXIT_CODE -ne 0 ]]; then
+  echo Failed to start in time >&2
+  exit 1
+fi

src/server/server.ts

@@ -55,6 +55,10 @@ export const createServer = (
     });
   });
 
+  app.get("/health", (req, res) => {
+    res.status(200).json({ ok: true });
+  });
+
   app.post("/", (req, res) => {
     const xAmzTarget = req.headers["x-amz-target"];