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// Copyright 2020-present the denosaurs team. All rights reserved. MIT license.
// deno-lint-ignore-fileexport type Indexable = Record<string, any>;
/** Performs a deep merge of `source` into `target`. * Mutates `target` only but not its objects and arrays. */export function merge<T extends Record<string, any>>(  target: T,  source: Indexable,): T {  const t = target as Record<string, unknown>;  const isObject = (obj: unknown) => obj && typeof obj === "object";
  if (!isObject(target) || !isObject(source)) {    return source as T;  }
  for (const key of Object.keys(source)) {    const targetValue = target[key];    const sourceValue = source[key];
    if (Array.isArray(targetValue) && Array.isArray(sourceValue)) {      t[key] = sourceValue;    } else if (isObject(targetValue) && isObject(sourceValue)) {      t[key] = merge(Object.assign({}, targetValue), sourceValue as Indexable);    } else {      t[key] = sourceValue;    }  }
  return t as T;}