<< short merge tags are not !!merge modified AND are now quoted, breaking some parsers

[nathanmcgarvey-modopayments]

I'm not sure if this is a bug or just something I'd like search engines to find:

due to yaml/go-yaml@fbd745b#r182994094
in combination with the version bump here in 8c018da from rc.3 to rc.4 of go-yaml.

Merge tags (<<) from YAML 1.1, when using operators such as *+ seem to now only quote the << operator and !! is not added, either.

go run yq.go eval-all '. as $item ireduce ({}; . *+ $item)' < /tmp/sample.yaml

where sample.yaml is:

---
defaults: &defaults
  foo: bar
  bat: baz
not_defaults:
  <<: *defaults
  foo: pizza
---
defaults2: &defaults2
  foo: bar
  bat: baz
not_defaults2:
  <<: *defaults2
  foo: pizza

example output from rc.3 of go-yaml which is used in v4.52.5 of yq:

---
defaults: &defaults
  foo: bar
  bat: baz
not_defaults:
  <<: *defaults
  foo: pizza
defaults2: &defaults2
  foo: bar
  bat: baz
not_defaults2:
  <<: *defaults2
  foo: pizza

example output from rc.4 of go-yaml which is used in v4.53.2 of yq:

---
defaults: &defaults
  foo: bar
  bat: baz
not_defaults:
  "<<": *defaults
  foo: pizza
defaults2: &defaults2
  foo: bar
  bat: baz
not_defaults2:
  "<<": *defaults2
  foo: pizza

[nathanmcgarvey-modopayments]

If this is a bug, please mark it as such, if this is "just how it goes", then some documentation on alternatives may be nice. (E.g. manually using !!merge, if that's correct.)

[W-Floyd]

I saw this a little bit ago too. It seems to apply unevenly to instances of this syntax.

Minimal example I'd made at the time:

package main

import (
	"os"

	"github.com/mikefarah/yq/v4/pkg/yqlib"
)

var yqExpr = `. as $item ireduce ({}; . *+ $item)`

func main() {

	data, _ := os.ReadFile("input.yaml")

	yqlibDecoder := yqlib.YamlFormat.DecoderFactory()
	yqlibEncoder := yqlib.YamlFormat.EncoderFactory()

	out, _ := yqlib.NewStringEvaluator().EvaluateAll(yqExpr, string(data), yqlibEncoder, yqlibDecoder)
	os.WriteFile("output.yaml", []byte(out), 0644)

}

with input:

constants:
  errorResponse: &errorResponse
    status: 200
endpoints:
  - condition: true
    <<: *errorResponse
other:
  <<: *errorResponse
  

produces:

constants:
  errorResponse: &errorResponse
    status: 200
endpoints:
  - condition: true
    !!merge <<: *errorResponse
other:
  "<<": *errorResponse

In fact, it also strips !!merge tags:

constants:
  errorResponse: &errorResponse
    status: 200
endpoints:
  - condition: true
    !!merge <<: *errorResponse
other:
  !!merge <<: *errorResponse

out:

constants:
  errorResponse: &errorResponse
    status: 200
endpoints:
  - condition: true
    !!merge <<: *errorResponse
other:
  "<<": *errorResponse

Another case:

constants:
  errorResponse: &errorResponse
    status: 200
endpoints:
  - condition: true
    !!merge <<: *errorResponse
other:
  foo:
    !!merge <<: *errorResponse

yields:

constants:
  errorResponse: &errorResponse
    status: 200
endpoints:
  - condition: true
    !!merge <<: *errorResponse
other:
  foo:
    "<<": *errorResponse

[mikefarah]

@ingydotnet / @ccoVeille do you guys have opinions on this? This happened when I updated from rc3 to rc4 ^

Doesn't seem quite right to me....

[ingydotnet]

I'll get this fixed asap. Monday at the latest.

[nathanmcgarvey-modopayments]

I'll get this fixed asap. Monday at the latest.

Friendly bump. 😄