Expressions service (#36885)

packages/kbn-interpreter/src/common/index.d.ts

@@ -18,3 +18,5 @@
  */
 
 export { Registry } from './lib/registry';
+
+export { fromExpression, Ast } from './lib/ast';

packages/kbn-interpreter/src/common/lib/ast.d.ts

@@ -0,0 +1,22 @@
+/*
+ * 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.
+ */
+
+export type Ast = unknown;
+
+export declare function fromExpression(expression: string): Ast;

src/legacy/core_plugins/data/public/expressions/expression_renderer.tsx

@@ -0,0 +1,59 @@
+/*
+ * 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 { useRef, useEffect } from 'react';
+import React from 'react';
+import { Ast } from '@kbn/interpreter/common';
+
+import { ExpressionRunnerOptions, ExpressionRunner } from './expression_runner';
+
+// Accept all options of the runner as props except for the
+// dom element which is provided by the component itself
+export type ExpressionRendererProps = Pick<
+  ExpressionRunnerOptions,
+  Exclude<keyof ExpressionRunnerOptions, 'element'>
+> & {
+  expression: string | Ast;
+};
+
+export type ExpressionRenderer = React.FC<ExpressionRendererProps>;
+
+export const createRenderer = (run: ExpressionRunner): ExpressionRenderer => ({
+  expression,
+  ...options
+}: ExpressionRendererProps) => {
+  const mountpoint: React.MutableRefObject<null | HTMLDivElement> = useRef(null);
+
+  useEffect(
+    () => {
+      if (mountpoint.current) {
+        run(expression, { ...options, element: mountpoint.current });
+      }
+    },
+    [expression, mountpoint.current]
+  );
+
+  return (
+    <div
+      ref={el => {
+        mountpoint.current = el;
+      }}
+    />
+  );
+};

src/legacy/core_plugins/data/public/expressions/expression_runner.ts

@@ -0,0 +1,72 @@
+/*
+ * 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 { Ast, fromExpression } from '@kbn/interpreter/common';
+
+import { RequestAdapter, DataAdapter } from 'ui/inspector/adapters';
+import { RenderFunctionsRegistry, Interpreter, Result } from './expressions_service';
+
+export interface ExpressionRunnerOptions {
+  // TODO use the real types here once they are ready
+  context?: object;
+  getInitialContext?: () => object;
+  element?: Element;
+}
+
+export type ExpressionRunner = (
+  expression: string | Ast,
+  options: ExpressionRunnerOptions
+) => Promise<Result>;
+
+export const createRunFn = (
+  renderersRegistry: RenderFunctionsRegistry,
+  interpreterPromise: Promise<Interpreter>
+): ExpressionRunner => async (expressionOrAst, { element, context, getInitialContext }) => {
+  // TODO: make interpreter initialization synchronous to avoid this
+  const interpreter = await interpreterPromise;
+  const ast =
+    typeof expressionOrAst === 'string' ? fromExpression(expressionOrAst) : expressionOrAst;
+
+  const response = await interpreter.interpretAst(ast, context || { type: 'null' }, {
+    getInitialContext: getInitialContext || (() => ({})),
+    inspectorAdapters: {
+      // TODO connect real adapters
+      requests: new RequestAdapter(),
+      data: new DataAdapter(),
+    },
+  });
+
+  if (element) {
+    if (response.type === 'render' && response.as) {
+      renderersRegistry.get(response.as).render(element, response.value, {
+        onDestroy: fn => {
+          // TODO implement
+        },
+        done: () => {
+          // TODO implement
+        },
+      });
+    } else {
+      // eslint-disable-next-line no-console
+      console.log('Unexpected result of expression', response);
+    }
+  }
+
+  return response;
+};

src/legacy/core_plugins/data/public/expressions/expressions_service.test.tsx

@@ -0,0 +1,217 @@
+/*
+ * 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 { fromExpression, Ast } from '@kbn/interpreter/common';
+
+import {
+  ExpressionsService,
+  RenderFunctionsRegistry,
+  RenderFunction,
+  Interpreter,
+  ExpressionsServiceDependencies,
+  Result,
+  ExpressionsSetup,
+} from './expressions_service';
+import { mount } from 'enzyme';
+import React from 'react';
+
+const waitForInterpreterRun = async () => {
+  // Wait for two ticks with empty callback queues
+  // This makes sure the runFn promise and actual interpretAst
+  // promise have been resolved and processed
+  await new Promise(resolve => setTimeout(resolve));
+  await new Promise(resolve => setTimeout(resolve));
+};
+
+describe('expressions_service', () => {
+  let interpreterMock: jest.Mocked<Interpreter>;
+  let renderFunctionMock: jest.Mocked<RenderFunction>;
+  let setupPluginsMock: ExpressionsServiceDependencies;
+  const expressionResult: Result = { type: 'render', as: 'abc', value: {} };
+
+  let api: ExpressionsSetup;
+  let testExpression: string;
+  let testAst: Ast;
+
+  beforeEach(() => {
+    interpreterMock = { interpretAst: jest.fn(_ => Promise.resolve(expressionResult)) };
+    renderFunctionMock = ({
+      render: jest.fn(),
+    } as unknown) as jest.Mocked<RenderFunction>;
+    setupPluginsMock = {
+      interpreter: {
+        getInterpreter: () => Promise.resolve({ interpreter: interpreterMock }),
+        renderersRegistry: ({
+          get: () => renderFunctionMock,
+        } as unknown) as RenderFunctionsRegistry,
+      },
+    };
+    api = new ExpressionsService().setup(setupPluginsMock);
+    testExpression = 'test | expression';
+    testAst = fromExpression(testExpression);
+  });
+
+  describe('expression_runner', () => {
+    it('should return run function', () => {
+      expect(typeof api.run).toBe('function');
+    });
+
+    it('should call the interpreter with parsed expression', async () => {
+      await api.run(testExpression, { element: document.createElement('div') });
+      expect(interpreterMock.interpretAst).toHaveBeenCalledWith(
+        testAst,
+        expect.anything(),
+        expect.anything()
+      );
+    });
+
+    it('should call the interpreter with given context and getInitialContext functions', async () => {
+      const getInitialContext = () => ({});
+      const context = {};
+
+      await api.run(testExpression, { getInitialContext, context });
+      const interpretCall = interpreterMock.interpretAst.mock.calls[0];
+
+      expect(interpretCall[1]).toBe(context);
+      expect(interpretCall[2].getInitialContext).toBe(getInitialContext);
+    });
+
+    it('should call the interpreter with passed in ast', async () => {
+      await api.run(testAst, { element: document.createElement('div') });
+      expect(interpreterMock.interpretAst).toHaveBeenCalledWith(
+        testAst,
+        expect.anything(),
+        expect.anything()
+      );
+    });
+
+    it('should call the render function with the result and element', async () => {
+      const element = document.createElement('div');
+
+      await api.run(testAst, { element });
+      expect(renderFunctionMock.render).toHaveBeenCalledWith(
+        element,
+        expressionResult.value,
+        expect.anything()
+      );
+      expect(interpreterMock.interpretAst).toHaveBeenCalledWith(
+        testAst,
+        expect.anything(),
+        expect.anything()
+      );
+    });
+  });
+
+  describe('expression_renderer', () => {
+    it('should call interpreter and render function when called through react component', async () => {
+      const ExpressionRenderer = api.ExpressionRenderer;
+
+      mount(<ExpressionRenderer expression={testExpression} />);
+
+      await waitForInterpreterRun();
+
+      expect(renderFunctionMock.render).toHaveBeenCalledWith(
+        expect.any(Element),
+        expressionResult.value,
+        expect.anything()
+      );
+      expect(interpreterMock.interpretAst).toHaveBeenCalledWith(
+        testAst,
+        expect.anything(),
+        expect.anything()
+      );
+    });
+
+    it('should call the interpreter with given context and getInitialContext functions', async () => {
+      const getInitialContext = () => ({});
+      const context = {};
+
+      const ExpressionRenderer = api.ExpressionRenderer;
+
+      mount(
+        <ExpressionRenderer
+          expression={testExpression}
+          getInitialContext={getInitialContext}
+          context={context}
+        />
+      );
+
+      await waitForInterpreterRun();
+
+      const interpretCall = interpreterMock.interpretAst.mock.calls[0];
+
+      expect(interpretCall[1]).toBe(context);
+      expect(interpretCall[2].getInitialContext).toBe(getInitialContext);
+    });
+
+    it('should call interpreter and render function again if expression changes', async () => {
+      const ExpressionRenderer = api.ExpressionRenderer;
+
+      const instance = mount(<ExpressionRenderer expression={testExpression} />);
+
+      await waitForInterpreterRun();
+
+      expect(renderFunctionMock.render).toHaveBeenCalledWith(
+        expect.any(Element),
+        expressionResult.value,
+        expect.anything()
+      );
+      expect(interpreterMock.interpretAst).toHaveBeenCalledWith(
+        testAst,
+        expect.anything(),
+        expect.anything()
+      );
+
+      instance.setProps({ expression: 'supertest | expression ' });
+
+      await waitForInterpreterRun();
+
+      expect(renderFunctionMock.render).toHaveBeenCalledTimes(2);
+      expect(interpreterMock.interpretAst).toHaveBeenCalledTimes(2);
+    });
+
+    it('should not call interpreter and render function again if expression does not change', async () => {
+      const ast = fromExpression(testExpression);
+
+      const ExpressionRenderer = api.ExpressionRenderer;
+
+      const instance = mount(<ExpressionRenderer expression={testExpression} />);
+
+      await waitForInterpreterRun();
+
+      expect(renderFunctionMock.render).toHaveBeenCalledWith(
+        expect.any(Element),
+        expressionResult.value,
+        expect.anything()
+      );
+      expect(interpreterMock.interpretAst).toHaveBeenCalledWith(
+        ast,
+        expect.anything(),
+        expect.anything()
+      );
+
+      instance.update();
+
+      await waitForInterpreterRun();
+
+      expect(renderFunctionMock.render).toHaveBeenCalledTimes(1);
+      expect(interpreterMock.interpretAst).toHaveBeenCalledTimes(1);
+    });
+  });
+});