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

99.13% Statements 228/230
97.67% Branches 84/86
100% Functions 8/8
99.11% Lines 225/227

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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 2282x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 1943x 1943x 1943x 1407x 1407x 1407x 25x     25x 25x 1x 1x 25x 1406x 1407x 1x 1x 1407x 1927x 1927x 1927x 1927x 1927x 1927x 1934x 462x 462x 462x 1927x 1943x 4x 2x 2x 4x 1943x 2x 2x 2x 2x 2x 2x 2x 2x 2919x 38x 90x 90x 90x 90x 2919x 48x 74x 74x 74x 74x 2881x 2165x 2165x 2165x 2165x 2160x 2165x 23x 23x 23x 23x 23x 23x 23x 23x 23x 23x 23x 23x 23x 23x 23x 21x 23x 23x 23x 9x 23x 14x 14x 23x 2165x 2919x 2x 2x 2x 2x 2x 2x 2x 2x 2x 887x 1x 1x 1x 887x 2x 2x 2x 2x 2x 2x 3458x 2039x 2039x 3458x 6x 6x 3458x 2x 2x 2x 2x 2x 2x 6301x 6301x 6689x 6689x 6689x 6015x 6689x 1x 1x 1x 6689x 6300x 2x 2x 2x 2x 2x 2x 2x 2x 5599x 5599x 5599x 5599x 5363x 5363x 5599x 4591x 5548x 149x 149x 4442x 4442x 5524x 5599x 5599x 2958x 5599x 5599x 2x 2x 2x 2x 2x 2x 2x 1606x 12x 12x 1594x 1594x 1606x 1548x 1548x 1548x 1548x 1548x 1291x 1291x 1291x 1291x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 20968x 20968x 20968x 20968x 20968x 20968x 20968x 20968x 11334x 20968x 8756x 8756x 8756x 4x 8756x 1x 1x 8756x 20968x  
/** @import { AssignmentExpression, Expression, Identifier, Pattern, PrivateIdentifier, Super, UpdateExpression, VariableDeclarator } from 'estree' */
/** @import { AST, Binding } from '#compiler' */
/** @import { AnalysisState, Context } from '../../types' */
/** @import { Scope } from '../../../scope' */
/** @import { NodeLike } from '../../../../errors.js' */
import * as e from '../../../../errors.js';
import { extract_identifiers, object } from '../../../../utils/ast.js';
import * as w from '../../../../warnings.js';
 
/**
 * @param {AssignmentExpression | UpdateExpression} node
 * @param {Pattern | Expression} argument
 * @param {AnalysisState} state
 */
export function validate_assignment(node, argument, state) {
	validate_no_const_assignment(node, argument, state.scope, false);
 
	if (argument.type === 'Identifier') {
		const binding = state.scope.get(argument.name);
 
		if (state.analysis.runes) {
			if (binding?.kind === 'derived') {
				e.constant_assignment(node, 'derived state');
			}
 
			if (binding?.kind === 'each') {
				e.each_item_invalid_assignment(node);
			}
		}
 
		if (binding?.kind === 'snippet') {
			e.snippet_parameter_assignment(node);
		}
	}
 
	let object = /** @type {Expression | Super} */ (argument);
 
	/** @type {Expression | PrivateIdentifier | null} */
	let property = null;
 
	while (object.type === 'MemberExpression') {
		property = object.property;
		object = object.object;
	}
 
	if (object.type === 'ThisExpression' && property?.type === 'PrivateIdentifier') {
		if (state.private_derived_state.includes(property.name)) {
			e.constant_assignment(node, 'derived state');
		}
	}
}
 
/**
 * @param {NodeLike} node
 * @param {Pattern | Expression} argument
 * @param {Scope} scope
 * @param {boolean} is_binding
 */
export function validate_no_const_assignment(node, argument, scope, is_binding) {
	if (argument.type === 'ArrayPattern') {
		for (const element of argument.elements) {
			if (element) {
				validate_no_const_assignment(node, element, scope, is_binding);
			}
		}
	} else if (argument.type === 'ObjectPattern') {
		for (const element of argument.properties) {
			if (element.type === 'Property') {
				validate_no_const_assignment(node, element.value, scope, is_binding);
			}
		}
	} else if (argument.type === 'Identifier') {
		const binding = scope.get(argument.name);
		if (
			binding?.kind === 'derived' ||
			binding?.declaration_kind === 'import' ||
			(binding?.declaration_kind === 'const' && binding.kind !== 'each')
		) {
			// e.invalid_const_assignment(
			// 	node,
			// 	is_binding,
			// 	// This takes advantage of the fact that we don't assign initial for let directives and then/catch variables.
			// 	// If we start doing that, we need another property on the binding to differentiate, or give up on the more precise error message.
			// 	binding.kind !== 'state' &&
			// 		binding.kind !== 'raw_state' &&
			// 		(binding.kind !== 'normal' || !binding.initial)
			// );
 
			// TODO have a more specific error message for assignments to things like `{:then foo}`
			const thing =
				binding.declaration_kind === 'import'
					? 'import'
					: binding.kind === 'derived'
						? 'derived state'
						: 'constant';
 
			if (is_binding) {
				e.constant_binding(node, thing);
			} else {
				e.constant_assignment(node, thing);
			}
		}
	}
}
 
/**
 * Validates that the opening of a control flow block is `{` immediately followed by the expected character.
 * In legacy mode whitespace is allowed inbetween. TODO remove once legacy mode is gone and move this into parser instead.
 * @param {{start: number; end: number}} node
 * @param {AnalysisState} state
 * @param {string} expected
 */
export function validate_opening_tag(node, state, expected) {
	if (state.analysis.source[node.start + 1] !== expected) {
		// avoid a sea of red and only mark the first few characters
		e.block_unexpected_character({ start: node.start, end: node.start + 5 }, expected);
	}
}
 
/**
 * @param {AST.Fragment | null | undefined} node
 * @param {Context} context
 */
export function validate_block_not_empty(node, context) {
	if (!node) return;
	// Assumption: If the block has zero elements, someone's in the middle of typing it out,
	// so don't warn in that case because it would be distracting.
	if (node.nodes.length === 1 && node.nodes[0].type === 'Text' && !node.nodes[0].raw.trim()) {
		w.block_empty(node.nodes[0]);
	}
}
 
/**
 * @param {VariableDeclarator} node
 * @param {AnalysisState} state
 */
export function ensure_no_module_import_conflict(node, state) {
	const ids = extract_identifiers(node.id);
	for (const id of ids) {
		if (
			state.ast_type === 'instance' &&
			state.scope === state.analysis.instance.scope &&
			state.analysis.module.scope.get(id.name)?.declaration_kind === 'import'
		) {
			// TODO fix the message here
			e.declaration_duplicate_module_import(node.id);
		}
	}
}
 
/**
 * A 'safe' identifier means that the `foo` in `foo.bar` or `foo()` will not
 * call functions that require component context to exist
 * @param {Expression | Super} expression
 * @param {Scope} scope
 */
export function is_safe_identifier(expression, scope) {
	let node = expression;
	while (node.type === 'MemberExpression') node = node.object;
 
	if (node.type !== 'Identifier') return false;
 
	const binding = scope.get(node.name);
	if (!binding) return true;
 
	if (binding.kind === 'store_sub') {
		return is_safe_identifier({ name: node.name.slice(1), type: 'Identifier' }, scope);
	}
 
	return (
		binding.declaration_kind !== 'import' &&
		binding.kind !== 'prop' &&
		binding.kind !== 'bindable_prop' &&
		binding.kind !== 'rest_prop'
	);
}
 
/**
 * @param {Expression | Super} node
 * @param {Context} context
 * @returns {boolean}
 */
export function is_pure(node, context) {
	if (node.type !== 'Identifier' && node.type !== 'MemberExpression') {
		return false;
	}
 
	const left = object(node);
	if (!left) return false;
 
	if (left.type === 'Identifier') {
		const binding = context.state.scope.get(left.name);
		if (binding === null) return true; // globals are assumed to be safe
	}
 
	// TODO add more cases (safe Svelte imports, etc)
	return false;
}
 
/**
 * Checks if the name is valid, which it is when it's not starting with (or is) a dollar sign or if it's a function parameter.
 * The second argument is the depth of the scope, which is there for backwards compatibility reasons: In Svelte 4, you
 * were allowed to define `$`-prefixed variables anywhere below the top level of components. Once legacy mode is gone, this
 * argument can be removed / the call sites adjusted accordingly.
 * @param {Binding | null} binding
 * @param {number | undefined} [function_depth]
 */
export function validate_identifier_name(binding, function_depth) {
	if (!binding) return;
 
	const declaration_kind = binding.declaration_kind;
 
	if (
		declaration_kind !== 'synthetic' &&
		declaration_kind !== 'param' &&
		declaration_kind !== 'rest_param' &&
		(!function_depth || function_depth <= 1)
	) {
		const node = binding.node;
 
		if (node.name === '$') {
			e.dollar_binding_invalid(node);
		} else if (node.name.startsWith('$')) {
			e.dollar_prefix_invalid(node);
		}
	}
}