All files / src/compiler/phases/3-transform/server/visitors VariableDeclaration.js

89.2% Statements 157/176
89.47% Branches 34/38
100% Functions 4/4
88.95% Lines 153/172

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 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 1732x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 28x 28x 28x 28x 28x 28x 3x 3x 3x 25x 28x 12x 12x 12x 1x 1x   1x           1x 12x 12x 12x 12x 13x 13x 13x 28x 28x 28x           13x 13x 13x 13x 13x                 28x 28x 28x 28x 28x 28x 2x 2x 2x 2x 2x 2x 2555x 2555x 2555x 2555x 2895x 2895x 2895x 2895x 2895x 500x 500x 500x 2395x 2895x 2041x 5x 5x 5x 5x 5x 5x 5x 5x 5x 5x 5x 31x 31x 31x 31x 31x 31x 31x 31x 5x 5x 2036x 2036x 2036x 2036x 2041x 2041x 2041x 2041x 2041x 2041x 2041x 987x 987x 987x 987x 987x 2036x 2036x 2036x 2036x 2036x 354x 354x 354x 354x 354x 2895x 2895x 2895x 2895x 2555x 2555x 2555x 2555x 2555x 2555x 2x 2x 2x 2x 2x 2x 2x 354x 354x 352x 352x 2x 2x 2x 2x 2x 2x 8x 8x 2x 2x 2x  
/** @import { VariableDeclaration, VariableDeclarator, Expression, CallExpression, Pattern, Identifier } from 'estree' */
/** @import { Binding } from '#compiler' */
/** @import { Context } from '../types.js' */
/** @import { Scope } from '../../../scope.js' */
import { extract_paths, is_expression_async } from '../../../../utils/ast.js';
import * as b from '../../../../utils/builders.js';
import { get_rune } from '../../../scope.js';
import { walk } from 'zimmerframe';
 
/**
 * @param {VariableDeclaration} node
 * @param {Context} context
 */
export function VariableDeclarationRunes(node, context) {
	const declarations = [];
 
	for (const declarator of node.declarations) {
		const init = declarator.init;
		const rune = get_rune(init, context.state.scope);
		if (!rune || rune === '$effect.tracking' || rune === '$inspect' || rune === '$effect.root') {
			declarations.push(/** @type {VariableDeclarator} */ (context.visit(declarator)));
			continue;
		}
 
		if (rune === '$props') {
			// remove $bindable() from props declaration
			const id = walk(declarator.id, null, {
				AssignmentPattern(node) {
					if (
						node.right.type === 'CallExpression' &&
						get_rune(node.right, context.state.scope) === '$bindable'
					) {
						const right = node.right.arguments.length
							? /** @type {Expression} */ (context.visit(node.right.arguments[0]))
							: b.id('undefined');
						return b.assignment_pattern(node.left, right);
					}
				}
			});
			declarations.push(b.declarator(id, b.id('$$props')));
			continue;
		}
 
		const args = /** @type {CallExpression} */ (init).arguments;
		const value =
			args.length === 0 ? b.id('undefined') : /** @type {Expression} */ (context.visit(args[0]));
 
		if (rune === '$derived.by') {
			declarations.push(
				b.declarator(/** @type {Pattern} */ (context.visit(declarator.id)), b.call(value))
			);
			continue;
		}
 
		if (declarator.id.type === 'Identifier') {
			declarations.push(b.declarator(declarator.id, value));
			continue;
		}

		if (rune === '$derived') {
			declarations.push(b.declarator(/** @type {Pattern} */ (context.visit(declarator.id)), value));
			continue;
		}

		declarations.push(...create_state_declarators(declarator, context.state.scope, value));
	}
 
	return {
		...node,
		declarations
	};
}
 
/**
 * @param {VariableDeclaration} node
 * @param {Context} context
 */
export function VariableDeclarationLegacy(node, { state, visit }) {
	/** @type {VariableDeclarator[]} */
	const declarations = [];
 
	for (const declarator of node.declarations) {
		const bindings = /** @type {Binding[]} */ (state.scope.get_bindings(declarator));
		const has_state = bindings.some((binding) => binding.kind === 'state');
		const has_props = bindings.some((binding) => binding.kind === 'bindable_prop');
 
		if (!has_state && !has_props) {
			declarations.push(/** @type {VariableDeclarator} */ (visit(declarator)));
			continue;
		}
 
		if (has_props) {
			if (declarator.id.type !== 'Identifier') {
				// Turn export let into props. It's really really weird because export let { x: foo, z: [bar]} = ..
				// means that foo and bar are the props (i.e. the leafs are the prop names), not x and z.
				const tmp = state.scope.generate('tmp');
				const paths = extract_paths(declarator.id);
				declarations.push(
					b.declarator(
						b.id(tmp),
						/** @type {Expression} */ (visit(/** @type {Expression} */ (declarator.init)))
					)
				);
				for (const path of paths) {
					const value = path.expression?.(b.id(tmp));
					const name = /** @type {Identifier} */ (path.node).name;
					const binding = /** @type {Binding} */ (state.scope.get(name));
					const prop = b.member(b.id('$$props'), b.literal(binding.prop_alias ?? name), true);
					declarations.push(
						b.declarator(path.node, b.call('$.value_or_fallback', prop, b.thunk(value)))
					);
				}
				continue;
			}
 
			const binding = /** @type {Binding} */ (state.scope.get(declarator.id.name));
			const prop = b.member(
				b.id('$$props'),
				b.literal(binding.prop_alias ?? declarator.id.name),
				true
			);
 
			/** @type {Expression} */
			let init = prop;
			if (declarator.init) {
				const default_value = /** @type {Expression} */ (visit(declarator.init));
				init = is_expression_async(default_value)
					? b.await(b.call('$.value_or_fallback_async', prop, b.thunk(default_value, true)))
					: b.call('$.value_or_fallback', prop, b.thunk(default_value));
			}
 
			declarations.push(b.declarator(declarator.id, init));
 
			continue;
		}
 
		declarations.push(
			...create_state_declarators(
				declarator,
				state.scope,
				/** @type {Expression} */ (declarator.init && visit(declarator.init))
			)
		);
	}
 
	return {
		...node,
		declarations
	};
}
 
/**
 * @param {VariableDeclarator} declarator
 * @param {Scope} scope
 * @param {Expression} value
 * @returns {VariableDeclarator[]}
 */
function create_state_declarators(declarator, scope, value) {
	if (declarator.id.type === 'Identifier') {
		return [b.declarator(declarator.id, value)];
	}
 
	const tmp = scope.generate('tmp');
	const paths = extract_paths(declarator.id);
	return [
		b.declarator(b.id(tmp), value), // TODO inject declarator for opts, so we can use it below
		...paths.map((path) => {
			const value = path.expression?.(b.id(tmp));
			return b.declarator(path.node, value);
		})
	];
}