src/vs/workbench/contrib/mergeEditor/browser/commands/commands.ts/mergeEditorCompare
async function mergeEditorCompare(viewModel: MergeEditorViewModel, editorService: IEditorService, inputNumber: 1 | 2) {

	editorService.openEditor(editorService.activeEditor!, { pinned: true });

	const model = viewModel.model;
	const base = model.base;
	const input = inputNumber === 1 ? viewModel.inputCodeEditorView1.editor : viewModel.inputCodeEditorView2.editor;

	const lineNumber = input.getPosition()!.lineNumber;
	await editorService.openEditor({
		original: { resource: base.uri },
		modified: { resource: input.getModel()!.uri },
		options: {
			selection: {
				startLineNumber: lineNumber,
				startColumn: 1,
			},
			revealIfOpened: true,
			revealIfVisible: true,
		} as ITextEditorOptions
	});
}