Move the human-editable configs to hconf

[Skidamek]

The server and client configs move from JSON to hconf, a small configuration format written for this mod, with an editor that changes config files in place instead of regenerating them. If you run a server or play with the mod, you do not need to do anything: your current config keeps working, and the mod moves it to the new format on the first save.

What was wrong with JSON

The old save path serialized the whole config object back to disk on every save:

• Comments were impossible.
• Formatting, key order and blank lines were regenerated.
• Any line the mod did not recognize was dropped.
• Deleting a key achieved nothing. It came back with its default value on the next boot.

Users learned not to touch their own config. That is backwards for the one file they are supposed to edit.

The format

# AutoModpack configuration - your edits and comments survive updates

# The name players see in the modpack UI.
modpackName: "My Server Pack"

# Cap on per-client transfer speed in MiB/s; 0 disables limiting.
bandwidthLimit: 0

modpack: {
  # a category, shown to players
  General: {
    # a group id, referenced by requires and breaksWith
    main: {
      syncedFiles: ["mods/*.jar", "kubejs/**"]
      excludedFiles: ["kubejs/server_scripts/**"]
    }
  }
}

Keys and values usually need no quotes. # starts a comment, to the end of the line. Braces nest, one entry per line. A JSON file with an object at the top is already a valid hconf file, so existing JSON configs parse as they are.

The parser is strict. A typo fails with the line, the column and the reason:

Invalid configuration server-config.hconf at line 1:17 (ADJACENT_VALUES):
two key tokens with no separator - hconf writes 'key: value'

What a save does now

The mod parses the current file, applies its changes to the document, and writes the result. Bytes outside a changed value are untouched:

# before: you added a note, a comment after the value, and commented a key out
# my note about the port
bindPort: 25565           # keep it low, my host is shared
# acceptProxyProtocol: true

# after: the mod changed the port and saved

# my note about the port
bindPort: 25566           # keep it low, my host is shared
# acceptProxyProtocol: true

Comments, key order, layout and line endings (LF, CRLF, CR) survive every save. Unknown keys and hand-added entries survive. One rule to know: deleting a documented key's line brings it back with its default value on the next boot. To disable a setting permanently, comment the line out instead; it stays off, and uncommenting it turns it back on.

Files

server-config.json becomes server-config.hconf, and client-config.json becomes client-config.hconf. Reads fall back to the old .json name, and the first save writes the .hconf file and removes the old one. If you have scripts or volume mounts that point at the old filenames, point them at the new ones. A corrupt config is never regenerated: the mod fails loudly, names the line and column, and expects a human to fix or remove the file.

For developers

• Config fields documented with @Comment get that comment on fresh generation and are materialized into old files that lack them. Other fields never reappear on their own.
• Saves are reconcile-based: scalars and objects are edited in place. Arrays are written from the model, because the model is read from the same file, so an element missing from the model is a deliberate removal, such as a normalized-away rule or an unpinned mod.
• The library ships as a zero-dependency jar under libs/. It has its own parser, writer and edit operations.

Testing

• HconfConfigsTest: fresh generation, legacy JSON reads, byte-preserving saves, idempotence, corrupt-file failures, tombstones staying out, migration on first save, rule removal.
• Autotester scenarios download-only on 1.21.11-fabric and installed-group-acquisition on 1.20.1-forge pass.