Start implementation of compat shim

src/tree/v2/providers/CompatibleBranchDataProvider.ts

@@ -0,0 +1,72 @@
+/*---------------------------------------------------------------------------------------------
+ *  Copyright (c) Microsoft Corporation. All rights reserved.
+ *  Licensed under the MIT License. See License.txt in the project root for license information.
+ *--------------------------------------------------------------------------------------------*/
+
+import { AzExtParentTreeItem, AzExtTreeDataProvider, AzExtTreeItem, IFindTreeItemContext, ITreeItemPickerContext } from '@microsoft/vscode-azext-utils';
+import { AppResource, AppResourceResolver } from '@microsoft/vscode-azext-utils/hostapi';
+import * as vscode from 'vscode';
+import { ApplicationResource, BranchDataProvider, ResourceModelBase } from '../../../api/v2/v2AzureResourcesApi';
+
+export class CompatibleBranchDataProvider<TResource extends ApplicationResource, TModel extends AzExtTreeItem & ResourceModelBase> extends AzExtTreeDataProvider implements BranchDataProvider<TResource, TModel> {
+    private readonly overrideOnDidChangeTreeDataEmitter = new vscode.EventEmitter<TModel | undefined>();
+
+    public constructor(private readonly resolver: AppResourceResolver, loadMoreCommandId: string) {
+        super(undefined as unknown as AzExtParentTreeItem, loadMoreCommandId);
+    }
+
+    //#region TreeDataProvider
+
+    public override readonly onDidChangeTreeData = this.overrideOnDidChangeTreeDataEmitter.event;
+
+    public override getParent(treeItem: TModel): Promise<TModel> {
+        // This method is redeclared to make TypeScript happier, but it's no more than a super call with extra casts
+        return super.getParent(treeItem) as Promise<TModel>;
+    }
+
+    public override getChildren(treeItem: TModel & AzExtParentTreeItem): Promise<TModel[]> {
+        // This method is redeclared to make TypeScript happier, but it's no more than a super call with extra casts
+        return super.getChildren(treeItem) as Promise<TModel[]>;
+    }
+
+    //#endregion
+
+    //#region BranchDataProvider
+
+    public async getResourceItem(element: TResource): Promise<TModel> {
+        const oldAppResource: AppResource = {
+            ...element,
+            type: element.type.type,
+            kind: element.type.kinds?.join(';'),
+        };
+
+        return this.resolver.resolveResource(/* TODO */'foo', oldAppResource) as Promise<TModel>;
+    }
+
+    //#endregion BranchDataProvider
+
+    //#region AzExtTreeDataProvider
+
+    public override refreshUIOnly(treeItem?: TModel): void {
+        // Override the default behavior to remain scoped to specific elements, like it ought
+        // And also, use overrideOnDidChangeTreeDataEmitter
+        this.overrideOnDidChangeTreeDataEmitter.fire(treeItem);
+    }
+
+    public override async showTreeItemPicker<T extends AzExtTreeItem>(expectedContextValues: string | RegExp | (string | RegExp)[], context: ITreeItemPickerContext & { canPickMany: true; }, startingTreeItem?: AzExtTreeItem): Promise<T[]>;
+    public override async showTreeItemPicker<T extends AzExtTreeItem>(_expectedContextValues: string | RegExp | (string | RegExp)[], _context: ITreeItemPickerContext, _startingTreeItem?: AzExtTreeItem): Promise<T> {
+        throw new Error('Use the Resources extension API to do showTreeItemPicker');
+    }
+
+    public override async findTreeItem<T extends AzExtTreeItem>(_fullId: string, _context: IFindTreeItemContext): Promise<T | undefined> {
+        throw new Error('Use the Resources extension API to do findTreeItem');
+    }
+
+    // TODO: this (probably?) shouldn't remain in the code we release, but will be helpful in testing to ensure we never access the root
+    // @ts-expect-error TypeScript is unhappy that we're overriding something that it doesn't know is secretly on the base class
+    private override get _rootTreeItem(): AzExtParentTreeItem {
+        throw new Error('The root tree item should not be accessed in a BranchDataProvider');
+    }
+
+    //#endregion AzExtTreeDataProvider
+}