CODEWITHSUNDEEP
node.jsgoogle-app-enginegoogle-cloud-datastoregoogle-cloud-platform
Emma K Alexandra
Emma K Alexandra

Reputation: 544

Properly comparing datastore keys in node

It appears that @google-cloud/datastore doesn't provide a method for comparing keys, and keys themselves aren't comparable. Is there a proper way to compare keys? I've taken a few stabs myself:

function compare(key1, key2) {
    return (key1.kind == key2.kind) && (key1.id == key2.id)
}

However, this doesn't work for keys with ancestors or keys with only kinds. So something more general might look like

function compare(key1, key2) {
    if (key1.path.length != key2.path.length) {
        return false;
    }

    for (var i = 0; i < key1.path.length; i++) {
        if (key1.path[i] != key2.path[i]) return false;
    }

    return true;
}

These solutions seem to work, but are kinda ugly to have laying around. Is there just a built in function I'm missing?

Upvotes: 1

Views: 215

Answers (1)

Artsiom Miksiuk
Artsiom Miksiuk

Reputation: 4303

You are not missing anything. There is no built in implementation of the key comparsion for datastore. I believe this is because it might be highly depends from business logic.

I'm using this implementation.

/**
 * Compare two keys on equality
 * @param {Object} key1 
 * @param {Object} key2 
 * @return {boolean}
 */
function compareKeys (key1, key2) {
    return key1.namespace === key2.namespace && _.isEqual(key1.path, key2.path); 
}

Update

I've created simple npm module in order to not copy/paste such solution everywhere.

https://www.npmjs.com/package/datastore-key-compare

Upvotes: 1

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