lilconfig

Find and load a tool's config file by searching up the directory tree.

Give it a tool name. It derives a set of conventional filenames, walks up from a starting directory, and returns the first file that exists and parses. The search and selection rules match cosmiconfig.

Installation

[dependencies]
lilconfig = "0.1"

Usage

Search upward from the current directory:

use lilconfig::SearcherBuilder;

let searcher = SearcherBuilder::new("myapp").build()?;
if let Some(found) = searcher.search_cwd()? {
    println!("config at {}: {:?}", found.filepath.display(), found.config);
}

Load one file by path:

use lilconfig::SearcherBuilder;

let searcher = SearcherBuilder::new("myapp").build()?;
let result = searcher.load("myapp.config.json")?;

An async surface mirrors the sync one. Build it with AsyncSearcherBuilder::new and await search and load.

Default search places

For a tool named myapp, search tries these names in each directory, in order:

package.json
.myapprc
.myapprc.json
.config/myapprc
.config/myapprc.json

package.json is special: the loader reads the key named after the tool (or the key set with package_prop) and treats a missing key as no match.

Loaders

A loader turns file text into a serde_json::Value. The defaults parse JSON for .json files and for extensionless files. Register more with loader:

use lilconfig::{loader, SearcherBuilder};
use serde_json::Value;

let searcher = SearcherBuilder::new("myapp")
    .loader(".toml", loader(|_path, text| {
        // parse `text` into a Value
        Ok(Value::Null)
    }))
    .build()?;

JavaScript config files (.js, .cjs, .mjs) have no default loader because this crate does not execute code. Register your own if you need them.

Config values

SearchResult.config is Option<Value>. None means the file was empty. Some(Value::Null) is an explicit null config. A search that finds nothing returns None for the whole result.

License

Licensed under the MIT license.