I am migrating an Apollo GraphQL API project written in JavaScript to TypeScript. And I am getting an error at finding a user code block, saying that:
var idArg: any Initializer provides no value for this binding element and the binding element has no default value.ts(2525)
async findOne({ id: idArg } = {}) {
// Red line here ^^^^^
const user = await this.knex('users')
.where('id', idArg)
.first();
if (!user) return;
return user;
}
Currently I added any to it without really knowing the actual solution, and the warning is gone:
async findOne({ id: idArg }: any = {}) {
const user = await this.knex('users')
.where('id', idArg)
.first();
if (!user) return;
return user;
}
However I'd still like to know the actual solution. Should I add a number type instead of any? But when I do that, the error is:
Type '{}' is not assignable to type 'number'.ts(2322).
Depending on what you want to accomplish there are a lot of ways in which you can solve this issue.
// The compiler checks the object { id: '1' } and it knows it has an id property
var { id } = { id: '1' }
/* The compiler is confused. It check the object {} and it knows it doesn't have
a property id1, so it is telling you it doesn't know where to get the value
for id1
*/
var { id1 } = {}
/* In this case the compiler knows the object doesn't have the property id2 but
since you provided a default value it uses it 'default value'.
*/
var { id2 = 'default value' } = {}
/* In your case there are a couple of solutions: */
// 1) Provide the value in the initializer
function findOne({ id: idArg } = { id: 'value here' }) {
console.log(id)
}
findOne()
// 2) Provide a default value
function findOne1({ id: idArg = 'value here 1' } = {}) {}
// 3) Provide initializer and type definition
function findOne2({ id: idArg}: { id?: number } = {}) {}
// 3) Do not provide initializer
function findOne3({ id: idArg}: { id: number }) {}