Assertio

Assertio is a tiny assertion library, similar to Node's built-in assert. It makes testing much easier by giving you lots of assertions you can run against your code.

Assertations

• assert(value: boolean, msg?)
• assertValue(value, predicate, msg?)
• assertFn(value: () => boolean, msg?)
• ensureArray(value, msg?)
• ensureObject(value, msg?)
• ensureString(value, msg?)
• ensureNumber(value, msg?)
• ensureBoolean(value, msg?)
• ensureNonVoid(value, msg?)
• ensureNonNull(value, msg?)
• ensureNonNullable(value, msg?)
• nonVoid(value, msg?)
• nonNull(value, msg?)
• nonNullable(value, msg?)
• never(msg?)
• neverValue(value, msg?)
• castValue(value)
• cast(value)
• as(value)
• maybe(value)

TypeScript transformer plugin

Assertio has a typescript transformer plugin to remove all assertations on production. See how to use typescript plugins https://github.com/cevek/ttypescript

tsconfig.json

{
    "compilerOptions": {
        // ...
        "plugins": [
            { "transform": "assertio/transform" },
        ]
    }
}