Cached api controller pipelines (#19880)

ref ENG-761
ref https://linear.app/tryghost/issue/ENG-761

Creating these pipelines is expensive, and we don't want to do it
repeatedly for the same controller. Adding caching should reduce the
amount of time spent setting up pipelines for each usage of the `get`
helper.

ghost/api-framework/lib/pipeline.js

@@ -160,6 +160,8 @@ const STAGES = {
     }
 };
 
+const controllerMap = new Map();
+
 /**
  * @description The pipeline runs the request through all stages (validation, serialisation, permissions).
  *
@@ -180,12 +182,16 @@ const STAGES = {
  * @return {Object}
  */
 const pipeline = (apiController, apiUtils, apiType) => {
+    if (controllerMap.has(apiController)) {
+        return controllerMap.get(apiController);
+    }
+
     const keys = Object.keys(apiController);
     const docName = apiController.docName;
 
     // CASE: api controllers are objects with configuration.
     //       We have to ensure that we expose a functional interface e.g. `api.posts.add` has to be available.
-    return keys.reduce((obj, method) => {
+    const result = keys.reduce((obj, method) => {
         const apiImpl = _.cloneDeep(apiController)[method];
 
         Object.freeze(apiImpl.headers);
@@ -267,6 +273,10 @@ const pipeline = (apiController, apiUtils, apiType) => {
         Object.assign(obj[method], apiImpl);
         return obj;
     }, {});
+
+    controllerMap.set(apiController, result);
+
+    return result;
 };
 
 module.exports = pipeline;

ghost/core/test/regression/mock-express-style/api-vs-frontend.test.js

@@ -33,8 +33,8 @@ describe('Frontend behavior tests', function () {
 
         beforeEach(function () {
             sinon.stub(themeEngine.getActive(), 'config').withArgs('posts_per_page').returns(2);
-            const postsAPI = require('../../../core/server/api/endpoints/posts-public');
-            postSpy = sinon.spy(postsAPI.browse, 'query');
+            const postsAPI = require('../../../core/server/api/endpoints').postsPublic;
+            postSpy = sinon.spy(postsAPI, 'browse');
         });
 
         afterEach(function () {
@@ -143,22 +143,20 @@ describe('Frontend behavior tests', function () {
                     });
             });
 
-            it('serve tag', function () {
+            it('serve tag', async function () {
                 const req = {
                     method: 'GET',
                     url: '/tag/bacon/',
                     host: 'example.com'
                 };
 
-                return localUtils.mockExpress.invoke(app, req)
-                    .then(function (response) {
-                        response.statusCode.should.eql(200);
-                        response.template.should.eql('tag');
+                const response = await localUtils.mockExpress.invoke(app, req);
+                response.statusCode.should.eql(200);
+                response.template.should.eql('tag');
 
-                        postSpy.args[0][0].options.filter.should.eql('(tags:\'bacon\'+tags.visibility:public)+type:post');
-                        postSpy.args[0][0].options.page.should.eql(1);
-                        postSpy.args[0][0].options.limit.should.eql(2);
-                    });
+                postSpy.args[0][0].filter.should.eql('tags:\'bacon\'+tags.visibility:public');
+                postSpy.args[0][0].page.should.eql(1);
+                postSpy.args[0][0].limit.should.eql(2);
             });
 
             it('serve tag rss', function () {