rs-env-validator

Typed environment variable validation with batch error reporting for Rust

Installation

[dependencies]
philiprehberger-env-validator = "0.4.0"

Usage

use philiprehberger_env_validator::Schema;

let config = Schema::new()
    .string("DATABASE_URL").build()
    .integer("PORT").default_value("3000").build()
    .boolean("DEBUG").default_value("false").build()
    .validate()?;

let port = config["PORT"].as_int().unwrap();

Float and URL Fields

let config = Schema::new()
    .float("RATE_LIMIT").default_value("1.5").build()
    .url("API_ENDPOINT").build()
    .validate()?;

let rate = config["RATE_LIMIT"].as_float().unwrap();
let endpoint = config["API_ENDPOINT"].as_str().unwrap();

With Choices

let config = Schema::new()
    .string("APP_ENV").choices(&["development", "staging", "production"]).build()
    .validate()?;

Numeric Range

let config = Schema::new()
    .integer("PORT").min(1024.0).max(65535.0).build()
    .float("RATE").min(0.0).max(1.0).build()
    .validate()?;

String Length

let config = Schema::new()
    .string("PASSWORD").min_length(8).max_length(64).build()
    .validate()?;

Custom Source (Testing)

use std::collections::HashMap;

let mut source = HashMap::new();
source.insert("PORT".to_string(), "8080".to_string());

let config = Schema::new()
    .integer("PORT").build()
    .validate_from(Some(&source))?;

Error Handling

match schema.validate() {
    Ok(config) => { /* use config */ }
    Err(e) => {
        for error in &e.errors {
            eprintln!("{}", error);
        }
    }
}

Type Conversions

use philiprehberger_env_validator::EnvValue;

let val: EnvValue = "hello".into();
let val: EnvValue = 42i64.into();
let val: EnvValue = 3.14f64.into();
let val: EnvValue = true.into();

// Display
println!("{}", val); // "true"

// Compare
assert_eq!(EnvValue::from(42i64), EnvValue::Int(42));

API

Function / Type	Description
Schema::new()	Create a new empty validation schema
schema.string(name)	Add a string field to the schema
schema.integer(name)	Add an integer field to the schema
schema.float(name)	Add a float field to the schema
schema.boolean(name)	Add a boolean field to the schema
schema.url(name)	Add a URL field to the schema
builder.required(bool)	Set whether the field is required (default: true)
builder.default_value(v)	Set a default value for the field
builder.choices(list)	Restrict allowed values to a set of choices
builder.min(v) / builder.max(v)	Numeric range bounds (integer / float)
builder.min_length(n) / builder.max_length(n)	String length bounds (string / url)
builder.build()	Finalize the field and return the schema
schema.validate()	Validate from environment variables
schema.validate_from(source)	Validate from a custom HashMap source
schema.field_count()	Number of fields registered in the schema
EnvValue	Enum: Str, Int, Float, Bool
EnvValue.as_string()	Render as String regardless of variant
ValidationError	Error containing a Vec<String> of all failures

Development

cargo test
cargo clippy -- -D warnings

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License

MIT