fileStorage/sagas: remove editor init from fileStorage

This is still a bit of a hack but is one step towards being able to
remove the 'editor' context.

src/editor/sagas.ts

@@ -0,0 +1,58 @@
+// SPDX-License-Identifier: MIT
+// Copyright (c) 2022 The Pybricks Authors
+
+import { monaco } from 'react-monaco-editor';
+import { eventChannel } from 'redux-saga';
+import { fork, put, race, select, take, takeEvery } from 'typed-redux-saga/macro';
+import {
+    fileStorageDidFailToReadFile,
+    fileStorageDidInitialize,
+    fileStorageDidReadFile,
+    fileStorageReadFile,
+} from '../fileStorage/actions';
+import { RootState } from '../reducers';
+
+function* handleDidCreateEditor(editor: monaco.editor.ICodeEditor): Generator {
+    // first, we need to be sure that file storage is ready
+
+    const isFileStorageInitialized = yield* select(
+        (s: RootState) => s.fileStorage.isInitialized,
+    );
+
+    if (!isFileStorageInitialized) {
+        yield* take(fileStorageDidInitialize);
+    }
+
+    // then we can load the most recently used file
+    // REVISIT: should this be here or elsewhere?
+
+    yield* put(fileStorageReadFile('main.py'));
+
+    const { succeeded } = yield* race({
+        succeeded: take(fileStorageDidReadFile.when((a) => a.fileName === 'main.py')),
+        failed: take(
+            fileStorageDidFailToReadFile.when((a) => a.fileName === 'main.py'),
+        ),
+    });
+
+    // TODO: what to do in case of failure?
+
+    if (succeeded) {
+        editor.setValue(succeeded.fileContents);
+    }
+
+    // TODO: subscribe to actions that act on the editor
+}
+
+function* monitorEditors(): Generator {
+    const ch = eventChannel<monaco.editor.ICodeEditor>((emit) => {
+        const subscription = monaco.editor.onDidCreateEditor(emit);
+        return () => subscription.dispose();
+    });
+
+    yield* takeEvery(ch, handleDidCreateEditor);
+}
+
+export default function* (): Generator {
+    yield* fork(monitorEditors);
+}

src/fileStorage/sagas.ts

@@ -6,9 +6,8 @@ import JSZip from 'jszip';
 import localForage from 'localforage';
 import { extendPrototype } from 'localforage-observable';
 import { eventChannel } from 'redux-saga';
-import { call, fork, getContext, put, takeEvery } from 'typed-redux-saga/macro';
+import { call, fork, put, takeEvery } from 'typed-redux-saga/macro';
 import Observable from 'zen-observable';
-import { EditorType } from '../editor/Editor';
 import { pythonFileExtension, pythonFileMimeType } from '../pybricksMicropython/lib';
 import { ensureError, timestamp } from '../utils';
 import {
@@ -269,20 +268,6 @@ function* initialize(): Generator {
 
         const fileNames = yield* call(() => files.keys());
 
-        // TODO: we should not be loading main.py here
-        // HACK: This assumes that editor is loaded before storage!
-        const editor = yield* getContext<EditorType>('editor');
-
-        if (editor) {
-            const main = yield* call(() => files.getItem<string>('main.py'));
-
-            if (main) {
-                editor.setValue(main);
-            }
-        } else if (process.env.NODE_ENV !== 'test') {
-            console.error('editor was not loaded, so main.py was not loaded');
-        }
-
         yield* put(fileStorageDidInitialize(fileNames));
     } catch (err) {
         yield* put(fileStorageDidFailToInitialize(ensureError(err)));

src/sagas.ts

@@ -7,6 +7,7 @@ import app from './app/sagas';
 import blePybricksService from './ble-pybricks-service/sagas';
 import ble from './ble/sagas';
 import { EditorType } from './editor/Editor';
+import editor from './editor/sagas';
 import errorLog from './error-log/sagas';
 import explorer from './explorer/sagas';
 import fileStorage from './fileStorage/sagas';
@@ -24,6 +25,7 @@ export default function* (): Generator {
         app(),
         blePybricksService(),
         ble(),
+        editor(),
         fileStorage(),
         lwp3BootloaderBle(),
         lwp3BootloaderProtocol(),