function mergeOne()

in packages/monorepo/src/utils/common.ts [71:113]

• 36 lines of code
• 14 McCabe index (conditional complexity)

  function mergeOne(target: any, source: any) {
    for (const key of Object.keys(source)) {
      const value = source[key];
      if (isObject(value)) {
        // if the value at the target is not an object, override it with an
        // object so we can continue the recursion
        if (typeof target[key] !== "object") {
          target[key] = value;
        }
        if (Array.isArray(value)) {
          if (Array.isArray(target[key])) {
            target[key].push(...value);
          } else {
            target[key] = value;
          }
        }
        mergeOne(target[key], value);
        // if the result of the merge is an empty object, it's because the
        // eventual value we assigned is `undefined`, and there are no
        // sibling concrete values alongside, so we can delete this tree.
        const output = target[key];
        if (
          typeof output === "object" &&
          Object.keys(output).length === 0 &&
          destructive
        ) {
          delete target[key];
        }
      } else if (value === undefined && destructive) {
        delete target[key];
      } else if (Array.isArray(value)) {
        if (Array.isArray(target[key])) {
          // Append to existing array
          target[key].push(...value);
        } else {
          // Override with array value
          target[key] = value;
        }
      } else if (typeof value !== "undefined") {
        target[key] = value;
      }
    }
  }