telvis/test/test.ts

Typescript/Javascript safe-navigation operator, also known as Elvis operator

import { suite, test, slow, timeout, skip, only } from "mocha-typescript"

import '../src/telvis'

interface A { b ?: B }
interface B { c ?: C }
interface C { hello ?: string }

@suite class Telvis {
    @test "Find a defined property"() {

        let a: A = { "b": { "c" : { hello: "world" }}}
        if(a.path("b", "c", "hello") !== "world") {
            throw new Error("World was not hello")
        }
    }

    @test "Safely get an undefined property" () {
        let a: A = { "b" : {} }
        if(a.path("b", "c", "hello") !== undefined) {
            throw new Error("World was not undefined")
        }
    }
}