fix: let framework known app has custom origin handler or not (#28)

auto set config.cors.hasCustomOriginHandler

app.js

@@ -6,6 +6,7 @@ module.exports = app => {
   app.config.coreMiddlewares.unshift('cors');
 
   // if security plugin enabled, and origin config is not provided, will only allow safe domains support CORS.
+  app.config.cors.hasCustomOriginHandler = !!app.config.cors.origin;
   app.config.cors.origin = app.config.cors.origin || function corsOrigin(ctx) {
     // origin is {protocol}{hostname}{port}...
     const origin = ctx.get('origin');

config/config.default.js

@@ -1,5 +1,3 @@
-'use strict';
-
 /**
  * cors default config
  * @member Config#cors

test/cors.default-config.test.js

@@ -24,6 +24,13 @@ describe('test/cors.default-config.test.js', () => {
       .expect(200);
   });
 
+  it('should hasCustomOriginHandler set to false', () => {
+    return app.httpRequest()
+      .get('/config')
+      .expect({ hasCustomOriginHandler: false })
+      .expect(200);
+  });
+
   it('should not set `Access-Control-Allow-Origin` to request origin header', () => {
     app.httpRequest()
       .get('/')

test/cors.origin-function.test.js

@@ -26,6 +26,13 @@ describe('test/cors.origin-function.test.js', () => {
       .expect(200);
   });
 
+  it('should hasCustomOriginHandler set to true', () => {
+    return app.httpRequest()
+      .get('/config')
+      .expect({ hasCustomOriginHandler: true })
+      .expect(200);
+  });
+
   it('should set `Access-Control-Allow-Origin` to request origin header', () => {
     return app.httpRequest()
       .get('/')

test/fixtures/apps/cors-default-config/app/router.js

@@ -7,6 +7,12 @@ module.exports = app => {
     };
   });
 
+  app.get('/config', async ctx => {
+    ctx.body = {
+      hasCustomOriginHandler: ctx.app.config.cors.hasCustomOriginHandler,
+    };
+  });
+
   app.post('/', async ctx => {
     ctx.body = {
       foo: 'bar',

test/fixtures/apps/cors.origin-function/app/router.js

@@ -7,6 +7,12 @@ module.exports = app => {
     };
   });
 
+  app.get('/config', async ctx => {
+    ctx.body = {
+      hasCustomOriginHandler: ctx.app.config.cors.hasCustomOriginHandler,
+    };
+  });
+
   app.post('/', async ctx => {
     ctx.body = {
       foo: 'bar',