figured out a more robust mocking pattern

packages/msgraph/src/mock/mock.js

@@ -9,35 +9,24 @@ import { fixtures } from './fixtures';
  * We need to document this in a way that the playground can use
  */
 
-// first step: mock with default data each msgraph function
-
-// ok that's fun, it's a http client
-
-// So this DOES use undici. So I think I can just write interceptors, rght?
-
 let mockAgent;
 let mockPool;
 
-// TODO this was copied out of util but it should be a common helper
-// actually we don't need this
-// export function getBaseUrl(state) {
-//   const{ resource, apiVersion} = state.configuration
-//   // if (isValidHttpUrl(resource)) return resource;
-
-//   const pathSuffix = apiVersion
-//     ? `${apiVersion}/${resource}`
-//     : `v1.0/${resource}`;
-//   return `https://graph.microsoft.com/${pathSuffix}`;
-// }
-
 // To make custom overrides easier, export some stanadard patterns
 export const patterns = {
   // TODO the regex might be a bit hard here, as we
   // need to distinguish the get drive patterns
   drives: /\/drives\//
 }
 
-export const enable = (state) => {
+// name: { pattern, data, options }
+const defaultRoutes = {
+  'drives': { pattern: patterns.drives, data: fixtures.driveResponse }
+}
+
+export const enable = (state, routes = {}) => {
+  // TODO if an agent already exists, should we destroy it?
+
   // set the global dispacher on undici
   mockAgent = new MockAgent();
 
@@ -48,37 +37,25 @@ export const enable = (state) => {
 
   mockPool = mockAgent.get('https://graph.microsoft.com');
 
-  enableDefaultRoutes();
-}
-
-// export const reset = (state) => {
-//   return enable(state)
-// }
-
-export const disable = () => {
-  throw "unimplemented"
-}
+  const mockRoutes = {
+    ...defaultRoutes,
+    ...routes
+  }
 
-/**
- * The problems with this are:
- * 1) When I register a persistent route, there's no way
- *    to disable it
- * 2) The first route to bind will always win, so custom
- *    overrides basically don't work.
- * Bugger.
- */
-export const enableDefaultRoutes = () => {
-  mockRoute(patterns.drives, fixtures.driveResponse)
+  // Set up all the mock routes
+  for (const name in mockRoutes) {
+    const { pattern, data, options } = mockRoutes[name];
+    mockRoute(pattern, data, options)
+  }
 }
 
 // API to enable a particular path to be mocked
 export const mockRoute = (path, data, options = {}) => {
-
-const jsonResponse = {
-  headers: {
-    'Content-Type': 'application/json',
-  },
-};
+  const jsonResponse = {
+    headers: {
+      'Content-Type': 'application/json',
+    },
+  };
 
   const { method = 'GET', headers, once = false } = options
   const scope = mockPool.intercept({

packages/msgraph/src/operations.js

@@ -15,8 +15,8 @@ const getRequestHandler = () => {
 /** Alternative, standardised, mock handler */
 
 // The runtime itself will call this to flick the whole thing into mock mode
-export const enableMock = (state) => {
-  enable(state)
+export const enableMock = (state, routes) => {
+  return enable(state, routes);
 }
 
 // Every adator uses this API to override mock mode

packages/msgraph/test/impl.test.js

@@ -1,6 +1,6 @@
 import { expect } from 'chai';
 import * as impl from '../src/impl';
-import { fixtures } from './fixtures';
+import { fixtures } from '../src/mock/fixtures';
 
 describe('getDrive', () => {
   // look how simple this unit test is now

packages/msgraph/test/mock.test.js

@@ -13,10 +13,14 @@ import Adaptor from '../src/index.js'
 
 const defaultState = { configuration: {resource: 'x'}, drives: {}};
 
-Adaptor.enableMock(defaultState);
 
 // Test all the default mock behaviours
 describe('default values', () => {
+  before(() => {
+    Adaptor.enableMock(defaultState);
+  });
+
+  // These can all use the default mock
   it('getDrive', async () => {
     const state = { ...defaultState };
 
@@ -32,19 +36,17 @@ describe('default values', () => {
   })
 })
 
-// TODO this doesn't work with Undici :(
-// Which means we don't have sufficient control of the mock
-describe.skip('custom values', () => {
+describe('custom values', () => {
   it('getDrive', async () => {
-    const state = { ...defaultState };
+    Adaptor.enableMock(defaultState, {
+      'drives': {
+        pattern: patterns.drives,
+        data: { x: 22 },
+        options: { once: true }
+      }
+    });
 
-    // This should override the default mock... (forever)
-    // This is annoying, I think the first mock to bind is the winner in case of a conflict
-    // That doesn't suit me!
-    // A shame because this is actually a really nice pattern
-    Adaptor.mock(patterns.drives, {
-      x: 22
-    })
+    const state = { ...defaultState };
 
     const result = await Adaptor.getDrive({ id: 'b!YXzpkoLwR06bxC8tNdg71m_' })(state)
     expect(result.drives).to.eql({ default:  { x: 22 } })