not_null.yml

name: not_null
topic: misc
args:
  required:
  - name: argument
    type: any
  variadic:
    type: any
returns:
  type: any
desc: |
  Returns the first argument that does not resolve to `null`.  This function
  accepts one or more arguments, and will evaluate them in order until a
  non null argument is encounted.  If all arguments values resolve to `null`,
  then a value of `null` is returned.
examples:
  test0:
    context: {a: !!null '', b: !!null '', c: [], d: foo}
    args: [no_exist, a, b, c, d]
    returns: []
  test1:
    context: {a: !!null '', b: !!null '', c: [], d: foo}
    args: [a, b, !!null '', d, c]
    returns: foo
  test2:
    context: {a: !!null '', b: !!null '', c: [], d: foo}
    args: [a, b]
    returns:
  test3:
    context: &data
      foo: -1
      zero: 0
      numbers: [-1, 3, 4, 5]
      array: [-1, 3, 4, 5, a, '100']
      strings: [a, b, c]
      decimals: [1.01, 1.2, -1.5]
      str: Str
      'false': false
      empty_list: []
      empty_hash: {}
      objects: {foo: bar, bar: baz}
      null_key:
    args: [unknown_key, str]
    returns: Str
  test4:
    context: *data
    args: [unknown_key, foo.bar, empty_list, str]
    returns: []
  test5:
    context: *data
    args: [unknown_key, null_key, empty_list, str]
    returns: []
  test6:
    context: *data
    args: [all, expressions, are_null]
    returns:
  test7:
    context: *data
    args: ['']
    error: invalid-arity