Wrong Order in Substitution Resolution Leads to Faulty Configuration

The substitution resolution is not performed in the order of the HOCON variable assignment.

Version: 0.3.58

Example:

pyhocon -i <INPUT_FILE>

Input file:

common = common
original = ${common}/original
result = ${original}
replaced = ${common}/replaced
result = ${replaced}
copy = ${result}

Result:

{
  "common": "common",
  "original": "common/original",
  "result": "common/replaced",
  "replaced": "common/replaced",
  "copy": "common/original"
}

Expected Result:

{
  "common": "common",
  "original": "common/original",
  "result": "common/replaced",
  "replaced": "common/replaced",
  "copy": "common/replaced"
}

Analyzing the substitution process, we see that the substitution is performed in the following order:

1. ${common} -> original = common/original
2. ${original} -> result = common/original
3. ${replaced} -> result = ${replaced} (HOWEVER: cannot be resolved because ${replaced} contains a substitution itself, thus the previous resolution stays for now! Here lies the issue!)
4. ${common} -> replaced = common/replaced
5. ${result} -> copy = common/original (Because the result = ${replaced} substitution could not be done until now, this apparently takes the previous substitution)

Now the next substitution iteration starts with the single left over substitution:

1. ${replaced} -> result = common/replaced

[afanasev]

Hi! I’ve created test based on your test data and managed to fix it and not break any other tests: https://github.com/chimpler/pyhocon/pull/284

[afanasev]

Better now: https://github.com/chimpler/pyhocon/pull/285