File size: 5,186 Bytes
f0743f4 | 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 | /**
* ESM-native object traversal utility
* Simplified implementation focused on the forEach use case
*/
export interface TraverseContext {
node: unknown;
path: (string | number)[];
parent: TraverseContext | undefined;
key: string | number | undefined;
isLeaf: boolean;
notLeaf: boolean;
isRoot: boolean;
notRoot: boolean;
level: number;
circular: TraverseContext | null;
update: (value: unknown, stopHere?: boolean) => void;
remove: () => void;
}
type ForEachCallback = (this: TraverseContext, value: unknown) => void;
// Type guards for proper typing
type TraversableObject = Record<string | number, unknown> | unknown[];
function isObject(value: unknown): value is TraversableObject {
if (value === null || typeof value !== 'object') {
return false;
}
// Treat these built-in types as leaf nodes, not objects to traverse
if (value instanceof Date) return false;
if (value instanceof RegExp) return false;
if (value instanceof Error) return false;
if (value instanceof URL) return false;
// Check for Buffer (Node.js)
if (typeof Buffer !== 'undefined' && Buffer.isBuffer(value)) return false;
// Check for TypedArrays and ArrayBuffer
if (ArrayBuffer.isView(value)) return false;
if (value instanceof ArrayBuffer) return false;
if (value instanceof SharedArrayBuffer) return false;
// Check for other built-in types that shouldn't be traversed
if (value instanceof Promise) return false;
if (value instanceof WeakMap) return false;
if (value instanceof WeakSet) return false;
if (value instanceof Map) return false;
if (value instanceof Set) return false;
// Check if it's a primitive wrapper object
const stringTag = Object.prototype.toString.call(value);
if (
stringTag === '[object Boolean]' ||
stringTag === '[object Number]' ||
stringTag === '[object String]'
) {
return false;
}
return true;
}
// Helper to safely set a property on an object or array
function setProperty(obj: TraversableObject, key: string | number, value: unknown): void {
if (Array.isArray(obj) && typeof key === 'number') {
obj[key] = value;
} else if (!Array.isArray(obj) && typeof key === 'string') {
obj[key] = value;
} else if (!Array.isArray(obj) && typeof key === 'number') {
// Handle numeric keys on objects
obj[key] = value;
}
}
// Helper to safely delete a property from an object
function deleteProperty(obj: TraversableObject, key: string | number): void {
if (Array.isArray(obj) && typeof key === 'number') {
// For arrays, we should use splice, but this is handled in remove()
// This function is only called for non-array deletion
return;
}
if (!Array.isArray(obj)) {
delete obj[key];
}
}
function forEach(obj: unknown, callback: ForEachCallback): void {
const visited = new WeakSet<object>();
function walk(node: unknown, path: (string | number)[] = [], parent?: TraverseContext): void {
// Check for circular references
let circular: TraverseContext | null = null;
if (isObject(node)) {
if (visited.has(node)) {
// Find the circular reference in the parent chain
let p = parent;
while (p) {
if (p.node === node) {
circular = p;
break;
}
p = p.parent;
}
return; // Skip circular references
}
visited.add(node);
}
const key = path.length > 0 ? path[path.length - 1] : undefined;
const isRoot = path.length === 0;
const level = path.length;
// Determine if this is a leaf node
const isLeaf =
!isObject(node) ||
(Array.isArray(node) && node.length === 0) ||
Object.keys(node).length === 0;
// Create context
const context: TraverseContext = {
node,
path: [...path],
parent,
key,
isLeaf,
notLeaf: !isLeaf,
isRoot,
notRoot: !isRoot,
level,
circular,
update(value: unknown) {
if (!isRoot && parent && key !== undefined && isObject(parent.node)) {
setProperty(parent.node, key, value);
}
this.node = value;
},
remove() {
if (!isRoot && parent && key !== undefined && isObject(parent.node)) {
if (Array.isArray(parent.node) && typeof key === 'number') {
parent.node.splice(key, 1);
} else {
deleteProperty(parent.node, key);
}
}
},
};
// Call the callback with the context
callback.call(context, node);
// Traverse children if not circular and is an object
if (!circular && isObject(node) && !isLeaf) {
if (Array.isArray(node)) {
for (let i = 0; i < node.length; i++) {
walk(node[i], [...path, i], context);
}
} else {
for (const [childKey, childValue] of Object.entries(node)) {
walk(childValue, [...path, childKey], context);
}
}
}
}
walk(obj);
}
// Main traverse function that returns an object with forEach method
export default function traverse(obj: unknown) {
return {
forEach(callback: ForEachCallback): void {
forEach(obj, callback);
},
};
}
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