MergeYaml giving unexpected results where JSON path value of key includes wildcards

[wabrit]

I am using

• OpenRewrite v1.19.4
• Maven plugin org.openrewrite.maven:rewrite-maven-plugin:4.46.0

I'm attempting to use the MergeYaml recipe in this scenario:

Old Yaml

list:
  services:
    foo:
      alpha: randomValue1
    bar:
      alpha: randomValue2

New Yaml

list:
  services:
    foo:
      alpha: randomValue1
      beta: fixedValue
    bar:
      alpha: randomValue2
      beta: fixedValue

I tried using MergeYaml with key set to $.list.services.* and yaml set to beta: fixedValue, but it gives me:

list:
  services:
    foo:
      alpha: randomValue1
    bar:
      alpha: randomValue2
    beta: fixedValue

[timtebeek]

Hi! Sounds like you want to insert a specific key into each element matching your wildcard key, correct?
I'm not seeing such a scenario in our existing test coverage yet, but it should be easy to replicate there.
Then you could even step through with the debugger to see if there's an easy fix in the MergeYaml recipe.

[wabrit]

Just for completeness', I have found that JsonPathMatcher appears not to support the wildcard * character as documented here.

e.g. for the same YAML mapping entry

  new JsonPathMatcher("$.a.b.c").matches(getCursor()); // returns TRUE
  new JsonPathMatcher("$.a.*.c").matches(getCursor()); // returns FALSE

Interestingly new JsonPathMatcher("$.a..c").matches(getCursor()) does appear to work as expected in this case.

As the failing scenario in this bug uses a trailing wildcard in the JSON path, it seems reasonably likely that the lack of support for * in JsonPathMatcher is contributing to the error (also because its a trailing wildcard, the use of recursive descent is not available).