Decoder creates object property with undefined value
w01fgang opened this issue · 3 comments
w01fgang commented
The actual behavior
const decoder = object({
id: number,
name: string,
address: optional(string),
});
decoder({ id: 1, name: "test" }).unwrap();
// returns this
{ id: 1, name: "test", address: undefined };Expected behavior
const decoder = object({
id: number,
name: string,
address: optional(string),
});
decoder({ id: 1, name: "test" }).unwrap();
// returns this
{ id: 1, name: "test" };Why it matters?
type Params = {|
host?: string,
port?: number,
|};
const decoder = exact({
host: optional(string),
port: optional(number),
});
const validate = guard(decoder);
const params = validate({});
const options = {
host: "localhost",
port: 3000,
...params,
};
console.log(options);
/*
{
host: undefined,
port: undefined
}
*/Workaround
const decoder = exact({
host: optional(string),
port: optional(number),
});
const validate = guard(decoder);
const params = JSON.parse(JSON.stringify(validate({})));
console.log(params);
/*
{}
*/nvie commented
Hi @w01fgang — thanks for reporting this! I've made a PR for this, and added some test cases to express the new behavior. I'll need to give this a pass over some real world code bases before I merge this in, because I want to make sure I don't break any behavior that is implicitly relied upon.