create a FE rpc mock (#3014)

Author: sawka

cmd/generatets/main-generatets.go

@@ -112,6 +112,14 @@ func generateWshClientApiFile(tsTypeMap map[reflect.Type]string) error {
 	fmt.Fprintf(&buf, "// SPDX-License-Identifier: Apache-2.0\n\n")
 	fmt.Fprintf(&buf, "// generated by cmd/generate/main-generatets.go\n\n")
 	fmt.Fprintf(&buf, "import { WshClient } from \"./wshclient\";\n\n")
+	fmt.Fprintf(&buf, "export interface MockRpcClient {\n")
+	fmt.Fprintf(&buf, "    mockWshRpcCall(client: WshClient, command: string, data: any, opts?: RpcOpts): Promise<any>;\n")
+	fmt.Fprintf(&buf, "    mockWshRpcStream(client: WshClient, command: string, data: any, opts?: RpcOpts): AsyncGenerator<any, void, boolean>;\n")
+	fmt.Fprintf(&buf, "}\n\n")
+	fmt.Fprintf(&buf, "let mockClient: MockRpcClient = null;\n\n")
+	fmt.Fprintf(&buf, "export function setMockRpcClient(client: MockRpcClient): void {\n")
+	fmt.Fprintf(&buf, "    mockClient = client;\n")
+	fmt.Fprintf(&buf, "}\n\n")
 	orderedKeys := utilfn.GetOrderedMapKeys(declMap)
 	fmt.Fprintf(&buf, "// WshServerCommandToDeclMap\n")
 	fmt.Fprintf(&buf, "class RpcApiType {\n")