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 351x 347x 347x 347x 347x 347x 347x 343x     343x 343x 343x 343x 343x 343x 343x 343x 343x 343x 343x 343x 343x 343x 343x 343x 343x 793x 793x 741x 789x 774x 774x 774x 774x 774x 774x 100x 100x 100x 774x 774x 774x 774x 352x 774x 270x 270x 504x 504x 504x 504x 741x 343x 343x 343x 343x 343x 256x 343x 216x 216x 12x 12x 12x 12x 12x 216x 216x 218x 218x 156x 156x 156x 218x 216x 347x 4x 4x 347x 351x 351x 351x  
/** @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();
}