available
json
JSON Parse & Manipulate
Parse, build, and edit JSON. Backed by serde_json in Rust, nested get/set, merge, and pretty-print included.
- parse & stringify
- Dot-path access
- Deep merge
- Pretty-print
Ecosystem
nenv
availableEnvironment Variables
Core Standard Library
Overview
nenv handles configuration from the environment. Call load(".env") at startup to merge a dotenv file into the process env, then read values with get_string, get_int, get_bool, and friends, each with a default if the key is missing.
Declare a schema of required keys and types and fail fast on boot if something's wrong, instead of crashing mid-request. For tests, spin up an isolated in-memory store so cases don't leak env vars into each other.
- .env loading
- Typed getters
- Schema validation
- Test isolation
Import
import
import "nenv" |
Quick start
quick start
import "nenv" |
|
nenv.load(".env") |
let port = nenv.get_int("PORT", 8080) |
let debug = nenv.get_bool("DEBUG", false) |
Capabilities
High-level overview of what nenv is for.
.env loading
Parse KEY=VALUE lines from a file and overlay them onto the process environment.
Typed getters
get_int, get_bool, get_float with defaults, no manual parseInt and no silent string "false" truthiness bugs.
Schema validation
List required keys and expected types; the app refuses to start if config is incomplete.
Isolated stores
In-memory env for unit tests that doesn't touch the real process environment.
API reference
27 functions and methods in nenv. Grouped by category from the standard library docs.
Loading `.env` files
| Signature | Description |
|---|---|
| nenv.load(path?, opts?) | Load one file (default `.env` in cwd). `opts`: `{override: bool}` (default `false`). Returns `int` count applied or `error`. |
| nenv.load_many(paths, opts?) | Load files in order; later keys apply when `override: true` or key not yet set. |
| nenv.load_defaults(opts?) | Load `.env` then `.env.local` if they exist. |
| nenv.parse(path) | Parse file without mutating process env; returns `{KEY: "value", ...}`. |
| nenv.parse_text(text) | Parse string content without applying. |
| nenv.find_up(filename?, start_dir?) | Walk parent directories for a file (default `.env`); returns path or `nil`. |
Process environment
| Signature | Description |
|---|---|
| nenv.get(key) | Read process env; `nil` or default if missing. |
| nenv.get(key, default) | Read process env; `nil` or default if missing. |
| nenv.set(key, value) | Mutate process env. |
| nenv.unset(key) | Mutate process env. |
| nenv.has(key) | `bool` - key exists. |
| nenv.all() | Snapshot of all process variables as an object. |
| nenv.require(key) | Returns string or `error` if missing. |
| nenv.get_int(key, default?) | Parse integer. |
| nenv.get_bool(key, default?) | Accept `true/false/1/0/yes/no/on/off`. |
| nenv.get_float(key, default?) | Parse float. |
| nenv.expand(text) | Expand `$VAR` and `${VAR}` using process env. |
| nenv.validate(schema) | `schema`: `{required: [...], types: {KEY: "int" |
Isolated stores
| Signature | Description |
|---|---|
| nenv.open(opts?) | New store handle (`int`). `opts`: `{inherit: bool}` - seed from current process env. |
| nenv.close(store) | Release handle. |
| nenv.from_object(map) | Build store from `{KEY: value}` object. |
| nenv.store_load(store, path, opts?) | Parse file into store only. |
| nenv.store_get(store, key, default?) | Read from store (plus inherit layer if configured). |
| nenv.store_set(store, key, value) | Set in store. |
| nenv.store_unset(store, key) | Remove from store. |
| nenv.store_all(store) | Merged object view. |
| nenv.store_apply(store, opts?) | Push store vars into process env. |
Related libraries
More from Core Standard Library.
available
io
File & Path I/O
Read and write files, stream large inputs, and work with paths. Blocking I/O can run on background threads.
- Whole-file read/write
- Streaming handles
- Background I/O
- Path helpers
available
time
Wall-Clock & Time Zones
Timestamps, formatting, parsing, and time zones. Built on chrono and chrono-tz, DST handled correctly.
- IANA time zones
- strftime formats
- Datetime values
- Date math