AwaitExpression() — svelte Function Reference

Source Code

packages/svelte/src/compiler/phases/2-analyze/visitors/AwaitExpression.js lines 10–45

export function AwaitExpression(node, context) {
	const tla = context.state.ast_type === 'instance' && context.state.function_depth === 1;

	// preserve context for awaits that precede other expressions in template or `$derived(...)`
	if (
		is_reactive_expression(
			context.path,
			context.state.derived_function_depth === context.state.function_depth
		) &&
		!is_last_evaluated_expression(context.path, node)
	) {
		context.state.analysis.pickled_awaits.add(node);
	}

	let suspend = tla;

	if (context.state.expression) {
		context.state.expression.has_await = true;

		suspend = true;
	}

	// disallow top-level `await` or `await` in template expressions
	// unless a) in runes mode and b) opted into `experimental.async`
	if (suspend) {
		if (!context.state.options.experimental.async) {
			e.experimental_async(node);
		}

		if (!context.state.analysis.runes) {
			e.legacy_await_invalid(node);
		}
	}

	context.next();
}