refactor: 💡 separate server-side function reg from executor (#44531) (#46775)

* refactor: 💡 separate server-side function reg from executor

* refactor: 💡 separate Canvas functionality of Interpreter

* refactor: 💡 simplify, move server fn init into Canavas

* fix: 🐛 adjust Expressions service usage after master merge

src/legacy/core_plugins/interpreter/public/canvas/load_legacy_server_function_wrappers.ts

@@ -0,0 +1,93 @@
+/*
+ * Licensed to Elasticsearch B.V. under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch B.V. licenses this file to you under
+ * the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+/**
+ * This file needs to be deleted by 8.0 release. It is here to load available
+ * server side functions and create a wrappers around them on client side, to
+ * execute them from client side. This functionality is used only by Canvas
+ * and all server side functions are in Canvas plugin.
+ *
+ * In 8.0 there will be no server-side functions, plugins will register only
+ * client side functions and if they need those to execute something on the
+ * server side, it should be respective function's internal implementation detail.
+ */
+
+import { get, identity } from 'lodash';
+// @ts-ignore
+import { npSetup } from 'ui/new_platform';
+import { FUNCTIONS_URL } from './consts';
+import { ajaxStream } from './ajax_stream';
+import { batchedFetch } from './batched_fetch';
+
+export function getType(node: any) {
+  if (node == null) return 'null';
+  if (typeof node === 'object') {
+    if (!node.type) throw new Error('Objects must have a type property');
+    return node.type;
+  }
+  return typeof node;
+}
+
+export function serializeProvider(types: any) {
+  return {
+    serialize: provider('serialize'),
+    deserialize: provider('deserialize'),
+  };
+
+  function provider(key: any) {
+    return (context: any) => {
+      const type = getType(context);
+      const typeDef = types[type];
+      const fn: any = get(typeDef, key) || identity;
+      return fn(context);
+    };
+  }
+}
+
+let cached: Promise<void> | null = null;
+
+export const loadLegacyServerFunctionWrappers = async () => {
+  if (!cached) {
+    cached = (async () => {
+      const serverFunctionList = await npSetup.core.http.get(FUNCTIONS_URL);
+      const types = npSetup.plugins.expressions.__LEGACY.types.toJS();
+      const { serialize } = serializeProvider(types);
+      const batch = batchedFetch({
+        ajaxStream: ajaxStream(
+          npSetup.core.injectedMetadata.getKibanaVersion(),
+          npSetup.core.injectedMetadata.getBasePath()
+        ),
+        serialize,
+      });
+
+      // For every sever-side function, register a client-side
+      // function that matches its definition, but which simply
+      // calls the server-side function endpoint.
+      Object.keys(serverFunctionList).forEach(functionName => {
+        const fn = () => ({
+          ...serverFunctionList[functionName],
+          fn: (context: any, args: any) => batch({ functionName, args, context }),
+        });
+        npSetup.plugins.expressions.registerFunction(fn);
+      });
+    })();
+  }
+
+  return cached;
+};

src/legacy/core_plugins/interpreter/public/interpreter.js

@@ -19,19 +19,12 @@
 
 import 'uiExports/interpreter';
 import { register, registryFactory } from '@kbn/interpreter/common';
-import { npSetup } from 'ui/new_platform';
 import { initializeInterpreter } from './lib/interpreter';
 import { registries } from './registries';
-
-import { ajaxStream } from './lib/ajax_stream';
 import { functions } from './functions';
 import { visualization } from './renderers/visualization';
 import { typeSpecs } from '../../../../plugins/expressions/common';
 
-const { http } = npSetup.core;
-const KIBANA_VERSION = npSetup.core.injectedMetadata.getKibanaVersion();
-const KIBANA_BASE_PATH = npSetup.core.injectedMetadata.getBasePath();
-
 // Expose kbnInterpreter.register(specs) and kbnInterpreter.registries() globally so that plugins
 // can register without a transpile step.
 global.kbnInterpreter = Object.assign(global.kbnInterpreter || {}, registryFactory(registries));
@@ -42,26 +35,13 @@ register(registries, {
   renderers: [visualization],
 });
 
-let _resolve;
-let _interpreterPromise;
-
-const initialize = async () => {
-  initializeInterpreter({
-    http,
-    ajaxStream: ajaxStream(KIBANA_VERSION, KIBANA_BASE_PATH),
-    typesRegistry: registries.types,
-    functionsRegistry: registries.browserFunctions,
-  }).then(interpreter => {
-    _resolve({ interpreter });
-  });
-};
+let interpreterPromise;
 
 export const getInterpreter = async () => {
-  if (!_interpreterPromise) {
-    _interpreterPromise = new Promise(resolve => _resolve = resolve);
-    initialize();
+  if (!interpreterPromise) {
+    interpreterPromise = initializeInterpreter();
   }
-  return await _interpreterPromise;
+  return await interpreterPromise;
 };
 
 export const interpretAst = async (...params) => {

src/legacy/core_plugins/interpreter/public/interpreter.test.js

@@ -36,7 +36,9 @@ jest.mock('@kbn/interpreter/common', () => ({
 }));
 
 const mockInterpreter = {
-  interpretAst: jest.fn(),
+  interpreter: {
+    interpretAst: jest.fn(),
+  }
 };
 jest.mock('./lib/interpreter', () => ({
   initializeInterpreter: jest.fn().mockReturnValue(Promise.resolve(mockInterpreter)),
@@ -71,12 +73,6 @@ describe('interpreter/interpreter', () => {
     it('initializes interpreter', async () => {
       await getInterpreter();
       expect(initializeInterpreter).toHaveBeenCalledTimes(1);
-      expect(initializeInterpreter.mock.calls[0][0]).toMatchObject({
-        ajaxStream: expect.any(Function),
-        http: expect.any(Object),
-        typesRegistry: expect.any(Function),
-        functionsRegistry: expect.any(Function),
-      });
     });
 
     it('only initializes interpreter once', async () => {
@@ -110,15 +106,15 @@ describe('interpreter/interpreter', () => {
     it('calls interpreter.interpretAst with the provided params', async () => {
       const params = [{}];
       await interpretAst(...params);
-      expect(mockInterpreter.interpretAst).toHaveBeenCalledTimes(1);
-      expect(mockInterpreter.interpretAst).toHaveBeenCalledWith(...params);
+      expect(mockInterpreter.interpreter.interpretAst).toHaveBeenCalledTimes(1);
+      expect(mockInterpreter.interpreter.interpretAst).toHaveBeenCalledWith(...params);
     });
 
     it('calls interpreter.interpretAst each time', async () => {
       const params = [{}];
       await interpretAst(...params);
       await interpretAst(...params);
-      expect(mockInterpreter.interpretAst).toHaveBeenCalledTimes(2);
+      expect(mockInterpreter.interpreter.interpretAst).toHaveBeenCalledTimes(2);
     });
   });
 

src/legacy/core_plugins/interpreter/public/lib/interpreter.test.ts

@@ -1,105 +0,0 @@
-/*
- * Licensed to Elasticsearch B.V. under one or more contributor
- * license agreements. See the NOTICE file distributed with
- * this work for additional information regarding copyright
- * ownership. Elasticsearch B.V. licenses this file to you under
- * the Apache License, Version 2.0 (the "License"); you may
- * not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *    http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing,
- * software distributed under the License is distributed on an
- * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
- * KIND, either express or implied.  See the License for the
- * specific language governing permissions and limitations
- * under the License.
- */
-
-import { FUNCTIONS_URL } from './consts';
-import { initializeInterpreter } from './interpreter';
-// eslint-disable-next-line @kbn/eslint/no-restricted-paths
-import { httpServiceMock } from '../../../../../core/public/http/http_service.mock';
-
-jest.mock('../../common', () => ({
-  serializeProvider: () => ({ serialize: () => ({}) }),
-}));
-
-jest.mock('./create_handlers', () => ({
-  createHandlers: () => ({}),
-}));
-
-it('loads server-side functions', async () => {
-  const http = httpServiceMock.createStartContract();
-  http.get.mockImplementation(async () => {
-    return {
-      hello: { name: 'hello' },
-      world: { name: 'world' },
-    };
-  });
-  const ajaxStream = jest.fn(async () => ({}));
-
-  await initializeInterpreter({
-    http,
-    ajaxStream,
-    typesRegistry: { toJS: () => ({}) },
-    functionsRegistry: { register: () => {} },
-  });
-
-  expect(http.get).toHaveBeenCalledTimes(1);
-  expect(http.get).toHaveBeenCalledWith(FUNCTIONS_URL);
-});
-
-it('registers client-side functions that pass through to the server', async () => {
-  const http = httpServiceMock.createStartContract();
-  http.get.mockImplementation(async () => {
-    return {
-      hello: { name: 'hello' },
-      world: { name: 'world' },
-    };
-  });
-
-  const register = jest.fn();
-  const ajaxStream = jest.fn(async ({ onResponse }) => {
-    onResponse({ id: 1, result: { hello: 'world' } });
-  });
-
-  await initializeInterpreter({
-    http,
-    ajaxStream,
-    typesRegistry: { toJS: () => ({}) },
-    functionsRegistry: { register },
-  });
-
-  expect(register).toHaveBeenCalledTimes(2);
-
-  const [hello, world] = register.mock.calls.map(([fn]) => fn());
-
-  expect(hello.name).toEqual('hello');
-  expect(typeof hello.fn).toEqual('function');
-  expect(world.name).toEqual('world');
-  expect(typeof world.fn).toEqual('function');
-
-  const context = {};
-  const args = { quote: 'All we have to decide is what to do with the time that is given us.' };
-
-  const result = await hello.fn(context, args);
-
-  expect(result).toEqual({ hello: 'world' });
-
-  expect(ajaxStream).toHaveBeenCalledWith({
-    url: FUNCTIONS_URL,
-    onResponse: expect.any(Function),
-    body: JSON.stringify({
-      functions: [
-        {
-          functionName: 'hello',
-          args,
-          context,
-          id: 1,
-        },
-      ],
-    }),
-  });
-});

src/legacy/core_plugins/interpreter/public/lib/interpreter.ts

@@ -17,44 +17,19 @@
  * under the License.
  */
 
-import { interpreterProvider, serializeProvider } from '../../common';
+import { interpreterProvider } from '../../common';
 import { createHandlers } from './create_handlers';
-import { batchedFetch } from './batched_fetch';
-import { FUNCTIONS_URL } from './consts';
-import { CoreStart } from '../../../../../core/public';
-
-interface Config {
-  http: CoreStart['http'];
-  ajaxStream: any; // TODO: Import this from kibana_utils/ajax_stream
-  typesRegistry: any;
-  functionsRegistry: any;
-}
-
-export async function initializeInterpreter(config: Config) {
-  const { http, ajaxStream, typesRegistry, functionsRegistry } = config;
-  const serverFunctionList = await http.get(FUNCTIONS_URL);
-  const types = typesRegistry.toJS();
-  const { serialize } = serializeProvider(types);
-  const batch = batchedFetch({ ajaxStream, serialize });
-
-  // For every sever-side function, register a client-side
-  // function that matches its definition, but which simply
-  // calls the server-side function endpoint.
-  Object.keys(serverFunctionList).forEach(functionName => {
-    functionsRegistry.register(() => ({
-      ...serverFunctionList[functionName],
-      fn: (context: any, args: any) => batch({ functionName, args, context }),
-    }));
-  });
+import { registries } from '../registries';
 
+export async function initializeInterpreter() {
   const interpretAst = async (ast: any, context: any, handlers: any) => {
     const interpretFn = await interpreterProvider({
-      types: typesRegistry.toJS(),
+      types: registries.types.toJS(),
       handlers: { ...handlers, ...createHandlers() },
-      functions: functionsRegistry.toJS(),
+      functions: registries.browserFunctions.toJS(),
     });
     return interpretFn(ast, context);
   };
 
-  return { interpretAst };
+  return { interpreter: { interpretAst } };
 }

x-pack/legacy/plugins/canvas/public/components/app/index.js

@@ -9,6 +9,7 @@ import { connect } from 'react-redux';
 import { compose, withProps } from 'recompose';
 import { registries } from 'plugins/interpreter/registries';
 import { getInterpreter } from 'plugins/interpreter/interpreter';
+import { loadLegacyServerFunctionWrappers } from 'plugins/interpreter/canvas/load_legacy_server_function_wrappers';
 import { getAppReady, getBasePath } from '../../state/selectors/app';
 import { appReady, appError } from '../../state/actions/app';
 import { elementsRegistry } from '../../lib/elements_registry';
@@ -71,6 +72,7 @@ register(registries, {
 const mapDispatchToProps = dispatch => ({
   setAppReady: () => async () => {
     try {
+      await loadLegacyServerFunctionWrappers();
       await getInterpreter();
 
       // Register the expression language with the Monaco Editor

x-pack/legacy/plugins/canvas/public/lib/run_interpreter.js

@@ -6,6 +6,7 @@
 
 import { fromExpression, getType } from '@kbn/interpreter/common';
 import { interpretAst } from 'plugins/interpreter/interpreter';
+import { loadLegacyServerFunctionWrappers } from 'plugins/interpreter/canvas/load_legacy_server_function_wrappers';
 import { notify } from './notify';
 
 /**
@@ -19,7 +20,8 @@ import { notify } from './notify';
  * @returns {promise}
  */
 export function runInterpreter(ast, context = null, options = {}) {
-  return interpretAst(ast, context)
+  return loadLegacyServerFunctionWrappers()
+    .then(() => interpretAst(ast, context))
     .then(renderable => {
       if (getType(renderable) === 'render') {
         return renderable;