Bug: del will not delete a map key named key when applied to the output of to_entries

[mikepilat]

Describe the bug

... | map(del(.key)) works on collections of records in general, except when applied to the output of to_entries. You can delete other keys, including .value, but specifically not .key. Odder still, if the input file has the same structure as what to_entries creates, you CAN delete the .key record. Examples below.

This behavior changed somewhere between v4.35.2 and v4.40.3.

Version of yq: 4.40.3
Operating system: mac, linux
Installed via: homebrew, asdf, github runner

Input Yaml

input.yml:

test1:
  bar: bar1
  foo: foo1
test2:
  bar: bar2
  foo: foo2

input_to_entries.yml:

- key: test1
  value:
    bar: bar1
    foo: foo1
- key: test2
  value:
    bar: bar2
    foo: foo2

Command
The command you ran:

yq 'to_entries | map(del(.key))' input.yaml

Actual behavior

- key: test1
  value:
    bar: bar1
    foo: foo1
- key: test2
  value:
    bar: bar2
    foo: foo2

Expected behavior

- value:
    bar: bar1
    foo: foo1
- value:
    bar: bar2
    foo: foo2

Additional context

It appears to be something specific about applying to the output of to_entries. If you apply the same transformation two steps via an intermediate file, you can delete the key:

yq 'to_entries' input.yaml > input_to_entries.yaml
yq 'map(del(.key))' input_to_entries.yaml

Gives the expected:

- value:
    bar: bar1
    foo: foo1
- value:
    bar: bar2
    foo: foo2

This appears to be specific to keys named key, as you can delete the value key from to_entries output:

yq 'to_entries | map(del(.value))' input.yaml

... gives:

- key: test1
- key: test2

Was working as expected in v4.35.2:

$yq -V
yq (https://github.com/mikefarah/yq/) version v4.35.2

$yq 'to_entries | map(del(.key))' input.yaml
- value:
    bar: bar1
    foo: foo1
- value:
    bar: bar2
    foo: foo2

[mikefarah]

Nice catch! Thanks for raising, will fix in the next release

[mikefarah]

Fixed in 4.40.4