Write integration tests (#719)

* Scaffold a simple test case for debugging

* Set up Jest environment that works with React

- Install and set up react-testing-library
- "Unignore" roughjs and browser-nativejs transformations
- Separate App component from ReactDOM

* Write first passing test

- Mock canvas
- Remove App file and mount/unmount ReactDOM on import

* Add tests for drag create behavior

* Fix comments in dragCreate

* Pin jest-mock-canvas dependency

* Remove dependency range for testing library

* Add tests for multi point mode and selection element

* Fix all tests due to decrease in updates to canvas when changing tools

* Disable state updates if component is unmounted

- Remove all event listeners
- Disable storing scene in state if component is unmounted

* Add tests for move and element selection

* Merge branch 'master' into add-integration-tests

* Add tests for resizing rectangle

* move unmounted check to syncActionResult method

* Use a custom test renderer instead of default testing-library functions

* Add custom query for selecting tools

* move files around

Co-authored-by: David Luzar <luzar.david@gmail.com>

src/tests/test-utils.ts

@@ -0,0 +1,30 @@
+import {
+  render,
+  queries,
+  RenderResult,
+  RenderOptions,
+} from "@testing-library/react";
+
+import * as toolQueries from "./queries/toolQueries";
+
+const customQueries = {
+  ...queries,
+  ...toolQueries,
+};
+
+type TestRenderFn = (
+  ui: React.ReactElement,
+  options?: Omit<RenderOptions, "queries">,
+) => RenderResult<typeof customQueries>;
+
+const renderApp: TestRenderFn = (ui, options) =>
+  render(ui, {
+    queries: customQueries,
+    ...options,
+  });
+
+// re-export everything
+export * from "@testing-library/react";
+
+// override render method
+export { renderApp as render };