All files / src/internal/client/reactivity deriveds.js

95.59% Statements 152/159
95.45% Branches 21/22
100% Functions 5/5
95.39% Lines 145/152

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 1702x 2x                 2x                   2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 10382x 10382x 10382x 72x 10382x 10310x 10310x 10310x 10310x 10382x 10382x 10382x 10382x 10382x 10382x 10382x 10382x 10382x 10382x 10382x 10382x 10382x 10382x 10382x 20x 20x 20x 10382x 10382x 10382x 2x 2x 2x 2x 2x 2x 2x 2x 5645x 5645x 5645x 5645x 2x 2x 2x 2x 2x 16337x 16337x 16337x 16337x 24x 24x 24x 28x 28x 14x 28x 14x 14x 28x 24x 16337x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 16324x 16324x 16324x 16324x 16324x 16324x 16324x 16324x 16324x 16324x 1x 1x 16323x 16323x 16323x 16323x 16323x 16324x 16324x 16324x 16324x 16324x 16324x               16319x 16319x 16324x 16324x 16324x 16324x 16324x 16118x 16118x 16118x 16324x 2x 2x 2x 2x 2x 14x 14x 14x 14x 14x 14x 14x 14x 14x 14x 14x 14x 14x 14x  
/** @import { Derived, Effect } from '#client' */
import { DEV } from 'esm-env';
import {
	CLEAN,
	DERIVED,
	DESTROYED,
	DIRTY,
	EFFECT_HAS_DERIVED,
	MAYBE_DIRTY,
	UNOWNED
} from '../constants.js';
import {
	active_reaction,
	active_effect,
	remove_reactions,
	set_signal_status,
	skip_reaction,
	update_reaction,
	increment_version,
	set_active_effect
} from '../runtime.js';
import { equals, safe_equals } from './equality.js';
import * as e from '../errors.js';
import { destroy_effect } from './effects.js';
import { inspect_effects, set_inspect_effects } from './sources.js';
 
/**
 * @template V
 * @param {() => V} fn
 * @returns {Derived<V>}
 */
/*#__NO_SIDE_EFFECTS__*/
export function derived(fn) {
	let flags = DERIVED | DIRTY;
 
	if (active_effect === null) {
		flags |= UNOWNED;
	} else {
		// Since deriveds are evaluated lazily, any effects created inside them are
		// created too late to ensure that the parent effect is added to the tree
		active_effect.f |= EFFECT_HAS_DERIVED;
	}
 
	/** @type {Derived<V>} */
	const signal = {
		children: null,
		deps: null,
		equals,
		f: flags,
		fn,
		reactions: null,
		v: /** @type {V} */ (null),
		version: 0,
		parent: active_effect
	};
 
	if (active_reaction !== null && (active_reaction.f & DERIVED) !== 0) {
		var derived = /** @type {Derived} */ (active_reaction);
		(derived.children ??= []).push(signal);
	}
 
	return signal;
}
 
/**
 * @template V
 * @param {() => V} fn
 * @returns {Derived<V>}
 */
/*#__NO_SIDE_EFFECTS__*/
export function derived_safe_equal(fn) {
	const signal = derived(fn);
	signal.equals = safe_equals;
	return signal;
}
 
/**
 * @param {Derived} derived
 * @returns {void}
 */
function destroy_derived_children(derived) {
	var children = derived.children;
 
	if (children !== null) {
		derived.children = null;
 
		for (var i = 0; i < children.length; i += 1) {
			var child = children[i];
			if ((child.f & DERIVED) !== 0) {
				destroy_derived(/** @type {Derived} */ (child));
			} else {
				destroy_effect(/** @type {Effect} */ (child));
			}
		}
	}
}
 
/**
 * The currently updating deriveds, used to detect infinite recursion
 * in dev mode and provide a nicer error than 'too much recursion'
 * @type {Derived[]}
 */
let stack = [];
 
/**
 * @param {Derived} derived
 * @returns {void}
 */
export function update_derived(derived) {
	var value;
	var prev_active_effect = active_effect;
 
	set_active_effect(derived.parent);
 
	if (DEV) {
		let prev_inspect_effects = inspect_effects;
		set_inspect_effects(new Set());
		try {
			if (stack.includes(derived)) {
				e.derived_references_self();
			}
 
			stack.push(derived);
 
			destroy_derived_children(derived);
			value = update_reaction(derived);
		} finally {
			set_active_effect(prev_active_effect);
			set_inspect_effects(prev_inspect_effects);
			stack.pop();
		}
	} else {
		try {
			destroy_derived_children(derived);
			value = update_reaction(derived);
		} finally {
			set_active_effect(prev_active_effect);
		}
	}
 
	var status =
		(skip_reaction || (derived.f & UNOWNED) !== 0) && derived.deps !== null ? MAYBE_DIRTY : CLEAN;
 
	set_signal_status(derived, status);
 
	if (!derived.equals(value)) {
		derived.v = value;
		derived.version = increment_version();
	}
}
 
/**
 * @param {Derived} signal
 * @returns {void}
 */
function destroy_derived(signal) {
	destroy_derived_children(signal);
	remove_reactions(signal, 0);
	set_signal_status(signal, DESTROYED);
 
	// TODO we need to ensure we remove the derived from any parent derives
 
	signal.children =
		signal.deps =
		signal.reactions =
		// @ts-expect-error `signal.fn` cannot be `null` while the signal is alive
		signal.fn =
			null;
}