WIP parse

Author: Rich-Harris

src/constants.js

@@ -0,0 +1,6 @@
+export const UNDEFINED = -1;
+export const HOLE = -2;
+export const NAN = -3;
+export const POSITIVE_INFINITY = -4;
+export const NEGATIVE_INFINITY = -5;
+export const NEGATIVE_ZERO = -6;

src/parse.js

@@ -1,7 +1,95 @@
+import {
+	HOLE,
+	NAN,
+	NEGATIVE_INFINITY,
+	NEGATIVE_ZERO,
+	POSITIVE_INFINITY,
+	UNDEFINED
+} from './constants.js';
+
 /**
  * Revive a value serialized with `devalue.stringify`
  * @param {string} serialized
  */
 export function parse(serialized) {
-	return 'TODO';
+	const values = JSON.parse(serialized);
+
+	if (typeof values === 'number') return get_value(values);
+
+	/** @param {number} index */
+	function get_value(index) {
+		if (index === UNDEFINED) return undefined;
+		if (index === NAN) return NaN;
+		if (index === POSITIVE_INFINITY) return Infinity;
+		if (index === NEGATIVE_INFINITY) return -Infinity;
+		if (index === NEGATIVE_ZERO) return -0;
+
+		return values[index];
+	}
+
+	let i = values.length;
+	while (i--) {
+		const value = values[i];
+
+		if (!value || typeof value !== 'object') continue;
+
+		if (Array.isArray(value)) {
+			if (typeof value[0] === 'string') {
+				const type = value[0];
+
+				switch (type) {
+					case 'Date':
+						values[i] = new Date(value[1]);
+						break;
+
+					case 'Set':
+						const set = new Set();
+						values[i] = set;
+						for (let j = 1; j < value.length; j += 1) {
+							set.add(get_value(value[j]));
+						}
+						break;
+
+					case 'RegExp':
+						values[i] = new RegExp(value[1], value[2]);
+						break;
+
+					case 'Object':
+						values[i] = Object(value[1]);
+						break;
+
+					case 'BigInt':
+						values[i] = BigInt(value[1]);
+						break;
+
+					case 'null':
+						const object = Object.create(null);
+				}
+			} else {
+				const array = new Array(value.length);
+
+				for (let i = 0; i < value.length; i += 1) {
+					const n = value[i];
+					if (n === HOLE) continue;
+
+					array[i] = get_value(n);
+				}
+
+				values[i] = array;
+			}
+		} else {
+			/** @type {Record<string, any>} */
+			const object = {};
+
+			for (const key in value) {
+				const n = value[key];
+				object[key] = get_value(n);
+			}
+
+			values[i] = object;
+		}
+	}
+
+	console.log(values);
+	return values[0];
 }

src/stringify.js

@@ -5,13 +5,14 @@ import {
 	is_primitive,
 	stringify_string
 } from './utils.js';
-
-const UNDEFINED = -1;
-const HOLE = -2;
-const NAN = -3;
-const POSITIVE_INFINITY = -4;
-const NEGATIVE_INFINITY = -5;
-const NEGATIVE_ZERO = -6;
+import {
+	HOLE,
+	NAN,
+	NEGATIVE_INFINITY,
+	NEGATIVE_ZERO,
+	POSITIVE_INFINITY,
+	UNDEFINED
+} from './constants.js';
 
 /**
  * Turn a value into a JSON string that can be parsed with `devalue.parse`
@@ -156,7 +157,7 @@ export function stringify(value) {
 	const index = flatten(value);
 
 	// special case — value is represented as a negative index
-	if (index < 0) return `[${index}]`;
+	if (index < 0) return `${index}`;
 
 	return `[${stringified.join(',')}]`;
 }

test/test.js

@@ -21,7 +21,7 @@ const fixtures = {
 			name: 'negative zero',
 			value: -0,
 			js: '-0',
-			json: '[-6]'
+			json: '-6'
 		},
 		{
 			name: 'positive decimal',
@@ -69,7 +69,7 @@ const fixtures = {
 			name: 'undefined',
 			value: undefined,
 			js: 'void 0',
-			json: '[-1]'
+			json: '-1'
 		},
 		{
 			name: 'null',
@@ -81,13 +81,13 @@ const fixtures = {
 			name: 'NaN',
 			value: NaN,
 			js: 'NaN',
-			json: '[-3]'
+			json: '-3'
 		},
 		{
 			name: 'Infinity',
 			value: Infinity,
 			js: 'Infinity',
-			json: '[-4]'
+			json: '-4'
 		},
 		{
 			name: 'RegExp',
@@ -342,17 +342,17 @@ for (const [name, tests] of Object.entries(fixtures)) {
 	test.run();
 }
 
-// for (const [name, tests] of Object.entries(fixtures)) {
-// 	const test = uvu.suite(`parse: ${name}`);
-// 	for (const t of tests) {
-// 		test(t.name, () => {
-// 			const actual = parse(t.json);
-// 			const expected = t.value;
-// 			assert.equal(actual, expected);
-// 		});
-// 	}
-// 	test.run();
-// }
+for (const [name, tests] of Object.entries(fixtures)) {
+	const test = uvu.suite(`parse: ${name}`);
+	for (const t of tests) {
+		test(t.name, () => {
+			const actual = parse(t.json);
+			const expected = t.value;
+			assert.equal(actual, expected);
+		});
+	}
+	test.run();
+}
 
 for (const fn of [devalue, stringify]) {
 	uvu.test(`${fn.name} throws for non-POJOs`, () => {

tsconfig.json

@@ -9,9 +9,9 @@
 		"diagnostics": true,
 		"noImplicitThis": true,
 		"noEmitOnError": true,
-		"lib": ["es5", "es6", "dom"]
+		"lib": ["es2022"],
+		"target": "es2022"
 	},
-	"target": "ES2018",
 	"module": "ES6",
 	"include": ["index.js", "src/*.js"],
 	"exclude": ["node_modules"]