convert editor service to saga

src/sagas/editor.test.ts

@@ -4,12 +4,39 @@
 import { Ace } from 'ace-builds';
 import { mock } from 'jest-mock-extended';
 import { AsyncSaga } from '../../test';
-import { reloadProgram } from '../actions/editor';
+import { open, reloadProgram, saveAs } from '../actions/editor';
 import editor from './editor';
 
+jest.mock('ace-builds');
+jest.mock('file-saver');
+
+test('open', async () => {
+    const saga = new AsyncSaga(editor);
+    const mockEditor = mock<Ace.EditSession>();
+    const data = new Uint8Array().buffer;
+
+    saga.setState({ editor: { current: mockEditor } });
+    saga.put(open(data));
+
+    expect(mockEditor.setValue).toBeCalled();
+
+    await saga.end();
+});
+
+test('saveAs', async () => {
+    const saga = new AsyncSaga(editor);
+    const mockEditor = mock<Ace.EditSession>();
+
+    saga.setState({ editor: { current: mockEditor } });
+    saga.put(saveAs());
+
+    expect(mockEditor.getValue).toBeCalled();
+
+    await saga.end();
+});
+
 test('reloadProgram', async () => {
     const saga = new AsyncSaga(editor);
-
     const mockEditor = mock<Ace.EditSession>();
 
     saga.setState({ editor: { current: mockEditor } });

src/sagas/editor.ts

@@ -2,18 +2,67 @@
 // Copyright (c) 2020 The Pybricks Authors
 
 import { Ace } from 'ace-builds';
+import FileSaver from 'file-saver';
 import { select, takeEvery } from 'redux-saga/effects';
-import { EditorActionType, EditorReloadProgramAction } from '../actions/editor';
+import {
+    EditorActionType,
+    EditorOpenAction,
+    EditorReloadProgramAction,
+    EditorSaveAsAction,
+} from '../actions/editor';
 import { RootState } from '../reducers';
 
+const decoder = new TextDecoder();
+
+function* open(action: EditorOpenAction): Generator {
+    const editor = (yield select(
+        (s: RootState) => s.editor.current,
+    )) as Ace.EditSession | null;
+
+    // istanbul ignore next: it is a bug to dispatch this action with no current editor
+    if (editor === null) {
+        console.error('open: No current editor');
+        return;
+    }
+
+    const text = decoder.decode(action.data);
+    editor.setValue(text);
+}
+
+// eslint-disable-next-line @typescript-eslint/no-unused-vars
+function* saveAs(action: EditorSaveAsAction): Generator {
+    const editor = (yield select(
+        (s: RootState) => s.editor.current,
+    )) as Ace.EditSession | null;
+
+    // istanbul ignore next: it is a bug to dispatch this action with no current editor
+    if (editor === null) {
+        console.error('saveAs: No current editor');
+        return;
+    }
+
+    const data = editor.getValue();
+    const blob = new Blob([data], { type: 'text/x-python;charset=utf-8' });
+    FileSaver.saveAs(blob, 'main.py');
+}
+
 // eslint-disable-next-line @typescript-eslint/no-unused-vars
 function* reloadProgram(_action: EditorReloadProgramAction): Generator {
     const editor = (yield select(
         (s: RootState) => s.editor.current,
-    )) as Ace.EditSession;
+    )) as Ace.EditSession | null;
+
+    // istanbul ignore next: it is a bug to dispatch this action with no current editor
+    if (editor === null) {
+        console.error('reloadProgram: No current editor');
+        return;
+    }
+
     editor.setValue(localStorage.getItem('program') || '');
 }
 
 export default function* (): Generator {
+    yield takeEvery(EditorActionType.Open, open);
+    yield takeEvery(EditorActionType.SaveAs, saveAs);
     yield takeEvery(EditorActionType.ReloadProgram, reloadProgram);
 }

src/services/editor.ts

@@ -1,39 +0,0 @@
-// SPDX-License-Identifier: MIT
-// Copyright (c) 2020 The Pybricks Authors
-
-import * as FileSaver from 'file-saver';
-import { Action, Dispatch } from '../actions';
-import { EditorActionType, EditorOpenAction } from '../actions/editor';
-import { RootState } from '../reducers';
-import { combineServices } from '.';
-
-const decoder = new TextDecoder();
-
-function open(action: Action, _dispatch: Dispatch, state: RootState): void {
-    if (action.type !== EditorActionType.Open) {
-        return;
-    }
-    // istanbul ignore next: currently, it is a bug if there is no current editor
-    if (state.editor.current === null) {
-        console.error('No current editor');
-        return;
-    }
-    const text = decoder.decode((action as EditorOpenAction).data);
-    state.editor.current.getDocument().setValue(text);
-}
-
-function saveAs(action: Action, _dispatch: Dispatch, state: RootState): void {
-    if (action.type !== EditorActionType.SaveAs) {
-        return;
-    }
-    // istanbul ignore next: currently, it is a bug if there is no current editor
-    if (state.editor.current === null) {
-        console.error('No current editor');
-        return;
-    }
-    const data = state.editor.current.getDocument().getValue();
-    const blob = new Blob([data], { type: 'text/x-python;charset=utf-8' });
-    FileSaver.saveAs(blob, 'main.py');
-}
-
-export default combineServices(open, saveAs);

src/services/index.ts

@@ -5,7 +5,6 @@ import { Middleware } from 'redux';
 import { Action, Dispatch } from '../actions';
 import { RootState } from '../reducers';
 import ble from './ble';
-import editor from './editor';
 import errorLog from './error-log';
 import hub from './hub';
 import bootloader from './lwp3-bootloader';
@@ -39,7 +38,7 @@ export function combineServices(...services: Service[]): Service {
     };
 }
 
-const rootService = combineServices(ble, bootloader, editor, errorLog, hub);
+const rootService = combineServices(ble, bootloader, errorLog, hub);
 
 const serviceMiddleware: Middleware = (store) => (next) => (action): unknown => {
     runService(rootService, action, store.dispatch, store.getState());

test/env.js

@@ -1,12 +1,16 @@
 const Environment = require('jest-environment-jsdom');
 
 /**
- * A custom environment to set the TextEncoder
+ * A custom environment to set TextDecoder/TextEncoder
  * Thanks https://stackoverflow.com/a/57713960/1976323
  */
 module.exports = class CustomTestEnvironment extends Environment {
     async setup() {
         await super.setup();
+        if (typeof TextDecoder === 'undefined') {
+            const { TextDecoder } = require('util');
+            this.global.TextDecoder = TextDecoder;
+        }
         if (typeof TextEncoder === 'undefined') {
             const { TextEncoder } = require('util');
             this.global.TextEncoder = TextEncoder;