A small collection of fixes (#48)

* fix: broken tests from #18

When the `done` function was removed in #18, the tests were not updated

* fix: TypeError when converting null or undefined

This will fix #34 by setting a default value on the
`lowerCaseKeys` function. You can get into this state when setting up a
test/demo incorrectly or using a lambda warmer (like serverless-warmup).
I am immediately returning because then a clear error can be shown.


Co-authored-by Mauricio Mercado <mau@maumercado.com>

Author: mattcan

index.js

@@ -21,7 +21,7 @@ const loadProbot = appFn => {
   return probot
 }
 
-const lowerCaseKeys = obj =>
+const lowerCaseKeys = (obj = {}) =>
   Object.keys(obj).reduce((accumulator, key) =>
     Object.assign(accumulator, { [key.toLocaleLowerCase()]: obj[key] }), {})
 
@@ -48,6 +48,12 @@ module.exports.serverless = appFn => {
     // Determine incoming webhook event type
     const headers = lowerCaseKeys(event.headers)
     const e = headers['x-github-event']
+    if (!e) {
+      return {
+        statusCode: 400,
+        body: 'X-Github-Event header is missing'
+      }
+    }
 
     // If body is expected to be base64 encoded, decode it and continue
     if (event.isBase64Encoded) {
@@ -59,10 +65,10 @@ module.exports.serverless = appFn => {
 
     // Bail for null body
     if (!event.body) {
-      return context.done(null, {
+      return {
         statusCode: 400,
         body: 'Event body is null.'
-      })
+      }
     }
 
     // Do the thing

tests/__snapshots__/index.test.js.snap

@@ -14,9 +14,14 @@ describe('serverless-lambda', () => {
 
   it('responds with the homepage', async () => {
     const event = { httpMethod: 'GET', path: '/probot' }
-    await handler(event, context)
-    expect(context.done).toHaveBeenCalled()
-    expect(context.done.mock.calls[0][0]).toMatchSnapshot()
+    const result = await handler(event, context)
+    expect(result).toMatchObject({
+      body: expect.any(String),
+      statusCode: 200,
+      headers: {
+        'Content-Type': 'text/html'
+      }
+    })
   })
 
   it('calls the event handler', async () => {
@@ -30,9 +35,9 @@ describe('serverless-lambda', () => {
       }
     }
 
-    await handler(event, context)
-    expect(context.done).toHaveBeenCalled()
+    const result = await handler(event, context)
     expect(spy).toHaveBeenCalled()
+    expect(result.statusCode).toBe(200)
   })
 
   it('responds with a 400 error when body is null', async () => {
@@ -44,10 +49,35 @@ describe('serverless-lambda', () => {
       }
     }
 
-    await handler(event, context)
-    expect(context.done).toHaveBeenCalledWith(null, expect.objectContaining({
-      statusCode: 400
-    }))
+    const result = await handler(event, context)
+    expect(result.statusCode).toBe(400)
+    expect(spy).not.toHaveBeenCalled()
+  })
+
+  it('responds with a 400 when no x-github-event header is sent (#48)', async () => {
+    const event = {
+      body: {
+        installation: { id: 1 }
+      },
+      headers: {
+        'x-github-delivery': 123
+      }
+    }
+
+    const result = await handler(event, context)
+    expect(spy).not.toHaveBeenCalled()
+    expect(result.statusCode).toBe(400)
+  })
+
+  it('responds with a 400 when no headers are present (#48)', async () => {
+    const event = {
+      body: {
+        installation: { id: 1 }
+      }
+    }
+
+    const result = await handler(event, context)
     expect(spy).not.toHaveBeenCalled()
+    expect(result.statusCode).toBe(400)
   })
 })