nest

nest is a DTL operation that groups sibling keys under a new wrapper mapping.

Use it when flat fields should become a nested object.

YOp

- nest:
    path: config
    keys: [host, port]
    under: database

Parameters

Parameter	Type	Required	Description
path	string	yes	Path to the parent mapping that contains the sibling keys.
keys	sequence of strings	yes	Existing sibling keys to move under the wrapper.
under	string	yes	New wrapper key name.

Behavior

• Requires path to exist and be a mapping.
• Requires every listed key to exist as a sibling in that mapping.
• Requires the wrapper key to be absent.
• Moves the listed keys under the new wrapper.

Errors

Error	Meaning
PATH_NOT_FOUND	Parent path does not exist.
NOT_A_MAPPING	Parent is not a mapping.
NOT_SIBLINGS	One or more listed keys are not siblings in the parent.
ALREADY_EXISTS	Wrapper key already exists.

Example

yops:
  - nest:
      path: config
      keys: [host, port]
      under: database

Input:

config:
  host: localhost
  port: 5432
  debug: true

Output:

config:
  database:
    host: localhost
    port: 5432
  debug: true