fix: Content Type case sensitivity (#134)

* fix: support content type header as Content-Type or content-type

Author: alexholtz

lambda/parse-request-body.ts

@@ -17,7 +17,7 @@ import { bodySchema, CONTENT_TYPES, headersSchema } from './schema';
 
 export function parseRequestBody(body: string, headers: IncomingHttpHeaders) {
   const headersResult = headersSchema.parse(headers);
-  const contentType = headersResult['content-type'];
+  const contentType = headersResult['content-type'] || headersResult['Content-Type'];
   switch (contentType) {
     case CONTENT_TYPES.JSON:
       return JSON.parse(body);

lambda/proxy.test.ts

@@ -117,6 +117,26 @@ describe('proxy', () => {
     expect(axios.post).toHaveBeenCalled();
   });
 
+  it('should forward a request when header is Content-Type', async () => {
+    const destinationUrl = 'https://approved.host/github-webhook/';
+    const endpointId = encodeURIComponent(destinationUrl);
+    const event: APIGatewayProxyWithLambdaAuthorizerEvent<any> = {
+      ...baseEvent,
+      headers: {
+        ...baseEvent.headers,
+        'content-type': undefined,
+        'Content-Type': 'application/json'
+      },
+      body: JSON.stringify(VALID_PUSH_PAYLOAD),
+      pathParameters: {
+        endpointId
+      }
+    };
+    const result = await handler(event);
+    expect(result).toEqual(expectedResponseObject);
+    expect(axios.post).toHaveBeenCalled();
+  });
+
   it('should not forward a request that does not come from an enterprise or managed user suffix', async () => {
     const destinationUrl = 'https://approved.host/github-webhook/';
     const endpointId = encodeURIComponent(destinationUrl);

lambda/schema.ts

@@ -11,9 +11,19 @@ export const CONTENT_TYPES = {
   URL_ENCODED: 'application/x-www-form-urlencoded'
 } as const;
 
-export const headersSchema = z.object({
-  'content-type': z.nativeEnum(CONTENT_TYPES)
-});
+export const headersSchema = z
+  .object({
+    'content-type': z.string().optional(),
+    'Content-Type': z.string().optional()
+  })
+  .refine(
+    headers => {
+      return headers['content-type'] || headers['Content-Type'];
+    },
+    {
+      message: 'Missing Content-Type header'
+    }
+  );
 
 export const axiosErrorSchema = z.object({
   response: z.object({