Support passing error objects to HealthCheckError

lib/terminus.js

@@ -15,6 +15,20 @@ function noopResolves () {
   return Promise.resolve()
 }
 
+function replaceErrors (key, value) {
+  if (value instanceof Error) {
+    const error = {}
+
+    Object.getOwnPropertyNames(value).forEach(function (key) {
+      error[key] = value[key]
+    })
+
+    return error
+  }
+
+  return value
+}
+
 async function sendSuccess (res, { info, verbatim }) {
   res.statusCode = 200
   res.setHeader('Content-Type', 'application/json')
@@ -46,7 +60,7 @@ async function sendFailure (res, options) {
       status: 'error',
       error: error,
       details: error
-    }))
+    }, replaceErrors))
   }
   res.end(FAILURE_RESPONSE)
 }

lib/terminus.spec.js

@@ -214,7 +214,7 @@ describe('Terminus', () => {
       expect(loggerRan).to.eql(true)
     })
 
-    it('includes error on reject', async () => {
+    it('includes error on reject (custom errors)', async () => {
       let onHealthCheckRan = false
 
       createTerminus(server, {
@@ -254,6 +254,45 @@ describe('Terminus', () => {
       })
     })
 
+    it('includes error on reject (Error objects)', async () => {
+      let onHealthCheckRan = false
+
+      const errors = [
+        new Error('test error 1'),
+        new Error('test error 2')
+      ]
+
+      createTerminus(server, {
+        healthChecks: {
+          '/health': () => {
+            onHealthCheckRan = true
+            const myError = new HealthCheckError('failed', errors)
+            return Promise.reject(myError)
+          }
+        }
+      })
+      server.listen(8000)
+
+      const res = await fetch('http://localhost:8000/health')
+      expect(res.status).to.eql(503)
+      expect(onHealthCheckRan).to.eql(true)
+      const json = await res.json()
+
+      const errorMessages = [{
+        message: errors[0].message,
+        stack: errors[0].stack.toString()
+      }, {
+        message: errors[1].message,
+        stack: errors[1].stack.toString()
+      }]
+
+      expect(json).to.deep.eql({
+        status: 'error',
+        error: errorMessages,
+        details: errorMessages
+      })
+    })
+
     it('returns 503 once signal received', (done) => {
       let responseAssertionsComplete = false