for_each doesn't affect type

[Rajin9601]

body = del(.)
for_each(["test1"]) -> |key, path| {
  ., err = set(., ["new", path], "test1")
}
.new.test2 = "test2"

this VRL program fails in compiling because of type of .new. (VRL Playground Link)

Error Log

error[E642]: parent path segment rejects this mutation
  ┌─ :5:6
  │
5 │ .new.test2 = "test2"
  │ ---- ^^^^^ querying a field of a non-object type is unsupported
  │ │
  │ this path resolves to a value of type undefined
  │
  = try: change parent value to object, before assignment
  =
  =     .new = {}
  =     .new.test2 = "test2"
  =
  = see documentation about error handling at https://errors.vrl.dev/#handling
  = see language documentation at https://vrl.dev
  = try your code in the VRL REPL, learn more at https://vrl.dev/examples

However, if it's inside an if statement instead of for_each, this vrl program can be compiled.

body = del(.)
if is_boolean(body.message) {
    ., err = set(., ["new", "test1"], "test1")
}
.new.test2 = "test2"

VRL Playground link

My theory is that .'s type is not changed by the for_each statement, which looks like a bug.

[jszwedko]

Aha, interesting, thanks for this report @Rajin9601 . That does look like a type definition bug to me.