Add explanatory comment and make onSuccess mandatory but nullable

Author: pullfrog[bot]

packages/studio/src/components/InitialCompositionLoader.tsx

@@ -94,6 +94,9 @@ export const InitialCompositionLoader: React.FC = () => {
 		const canvasContentFromUrl = deriveCanvasContentFromUrl();
 
 		if (canvasContent) {
+			// If the URL points to a different composition than the one currently
+			// displayed, switch to it. This handles the case where the URL is
+			// updated externally (e.g. after duplicating a composition).
 			if (
 				canvasContentFromUrl &&
 				canvasContentFromUrl.type === 'composition' &&

packages/studio/src/components/NewComposition/CodemodFooter.tsx

@@ -18,7 +18,7 @@ export const CodemodFooter: React.FC<{
 	readonly errorNotification: string;
 	readonly genericSubmitLabel: string;
 	readonly submitLabel: (options: {relativeRootPath: string}) => string;
-	readonly onSuccess?: () => void;
+	readonly onSuccess: (() => void) | null;
 }> = ({
 	codemod,
 	valid,

packages/studio/src/components/NewComposition/DeleteComposition.tsx

@@ -65,6 +65,7 @@ const DeleteCompositionLoaded: React.FC<{
 						}
 						codemod={codemod}
 						valid
+						onSuccess={null}
 					/>
 				</ModalFooterContainer>
 			</form>

packages/studio/src/components/NewComposition/RenameComposition.tsx

@@ -104,6 +104,7 @@ const RenameCompositionLoaded: React.FC<{}> = () => {
 						submitLabel={({relativeRootPath}) => `Modify ${relativeRootPath}`}
 						codemod={codemod}
 						valid={valid}
+						onSuccess={null}
 					/>
 				</ModalFooterContainer>
 			</form>