JavaScript ES6+ compare fields in arrays of objects

Spinning my wheels here. Seems simple conceptually but JS is trying to kill me.

Two arrays of objects:

let allProfileUsers = [
    {
        id: "0b4cd920-31da-11ec-a31c-cd844bfb73be",
        auth_user_id: "fea98060-31ac-11ec-81f6-9b65b19a8154",
        active: true
    },
    {
        id: "0b4f9840-31da-11ec-a31c-cd844bfb73be",
        auth_user_id: "fea73670-31ac-11ec-81f6-9b65b19a8154",
        active: true
    },
    {
        id: "0b51e230-31da-11ec-a31c-cd844bfb73be",
        auth_user_id: "fea98060-31ac-11ec-81f6-9b65b19a8154",
        active: true
    }
];

let allAuthUsers = [
    {
        id: "fea4c570-31ac-11ec-81f6-9b65b19a8154",
        username: "user1",
        active: true,
    },
    {
        id: "fea73670-31ac-11ec-81f6-9b65b19a8154",
        username: "user2",
        active: true,
    },
    {
        id: "fea98060-31ac-11ec-81f6-9b65b19a8154",
        username: "user3",
        active: true,
    }
];

I need to compare the “id” field in the objects in the first array to the “auth_user_id” field in the second set of arrays. Basically, all users in array one should exist in array two, based on the match-up of those two fields.

This doesn’t work (not shorthand so it’s easy to debug):

let allMatched = allAuthUsers.every(x => {
    return allProfileUsers.some(pu => {
        return x.id === pu.auth_user_id;
    });
});

…returns false;

Of course, I could manually loop through each value and compare them. I don’t want that unless there’s no other way.

I have to think JS is capable of a more elegant one-liner with arrows. In fact, frustratingly, I know I’ve done this before, but I just can’t seem to make it happen today.

Answer

Buddy, I feel the answer is in your question. You need to loop through the first array(allProfileUsers) first and then check if it exist in second(allAuthUsers).

let allMatched = allProfileUsers.every(pu => {
    return allAuthUsers.some(x => {
            return x.id === pu.auth_user_id;
    });
});