All files / src/compiler/phases/2-analyze/visitors LabeledStatement.js

97.95% Statements 96/98
95.83% Branches 23/24
100% Functions 1/1
97.89% Lines 93/95

Press n or j to go to the next uncovered block, b, p or k for the previous block.

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 962x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 332x 328x 328x 328x 328x 328x 328x 324x     324x 324x 324x 324x 324x 324x 324x 324x 324x 324x 324x 324x 324x 324x 324x 324x 324x 752x 752x 705x 739x 737x 737x 737x 737x 737x 737x 98x 98x 98x 737x 737x 737x 737x 334x 737x 253x 253x 484x 484x 484x 484x 705x 324x 324x 324x 324x 324x 248x 324x 210x 210x 12x 12x 12x 12x 12x 210x 210x 212x 212x 152x 152x 152x 212x 210x 328x 4x 4x 328x 332x 332x 332x  
/** @import { Expression, LabeledStatement } from 'estree' */
/** @import { AST, ReactiveStatement, SvelteNode } from '#compiler' */
/** @import { Context } from '../types' */
import * as e from '../../../errors.js';
import { extract_identifiers, object } from '../../../utils/ast.js';
import * as w from '../../../warnings.js';
 
/**
 * @param {LabeledStatement} node
 * @param {Context} context
 */
export function LabeledStatement(node, context) {
	if (node.label.name === '$') {
		const parent = /** @type {SvelteNode} */ (context.path.at(-1));
 
		const is_reactive_statement =
			context.state.ast_type === 'instance' && parent.type === 'Program';
 
		if (is_reactive_statement) {
			if (context.state.analysis.runes) {
				e.legacy_reactive_statement_invalid(node);
			}
 
			// Find all dependencies of this `$: {...}` statement
			/** @type {ReactiveStatement} */
			const reactive_statement = {
				assignments: new Set(),
				dependencies: []
			};
 
			context.next({
				...context.state,
				reactive_statement,
				function_depth: context.state.scope.function_depth + 1
			});
 
			// Every referenced binding becomes a dependency, unless it's on
			// the left-hand side of an `=` assignment
			for (const [name, nodes] of context.state.scope.references) {
				const binding = context.state.scope.get(name);
				if (binding === null) continue;
 
				for (const { node, path } of nodes) {
					/** @type {Expression} */
					let left = node;
 
					let i = path.length - 1;
					let parent = /** @type {Expression} */ (path.at(i));
					while (parent.type === 'MemberExpression') {
						left = parent;
						parent = /** @type {Expression} */ (path.at(--i));
					}
 
					if (
						parent.type === 'AssignmentExpression' &&
						parent.operator === '=' &&
						parent.left === left
					) {
						continue;
					}
 
					reactive_statement.dependencies.push(binding);
					break;
				}
			}
 
			context.state.reactive_statements.set(node, reactive_statement);
 
			if (
				node.body.type === 'ExpressionStatement' &&
				node.body.expression.type === 'AssignmentExpression'
			) {
				let ids = extract_identifiers(node.body.expression.left);
				if (node.body.expression.left.type === 'MemberExpression') {
					const id = object(node.body.expression.left);
					if (id !== null) {
						ids = [id];
					}
				}
 
				for (const id of ids) {
					const binding = context.state.scope.get(id.name);
					if (binding?.kind === 'legacy_reactive') {
						// TODO does this include `let double; $: double = x * 2`?
						binding.legacy_dependencies = Array.from(reactive_statement.dependencies);
					}
				}
			}
		} else if (!context.state.analysis.runes) {
			w.reactive_declaration_invalid_placement(node);
		}
	}
 
	context.next();
}