# Store

To understand how the store works, first read the explanation.

The get method accepts several different signatures:

store.get('Book', 123, 'title');
// returns: "a string"

Returns the value of the field for the requested entity. If the type of the field is a scalar type (e.g. Int, String, etc.) the value is returned. If the type of the field is a type (ie. a Book or User), a reference is returned:

// assuming the schema is `type Book { owner: User }`

store.get('Book', 123, 'owner');
// returns: { $ref: { typeName: 'User', key: 456 } }

If a field is not specified as the third argument, a reference is returned.

store.get('Book', 123);
// returns: { $ref: { typeName: 'Book', key: 123 } }

A reference can be used as first argument to get values for that reference:

const $book = store.get('Book', 123);

store.get($book, 'title');
// returns: "a string"

When calling get with only a typeName, a new ref is returned:

store.get('Book');
// returns: { $ref: { typeName: 'Book', key: 123 } }

The key will be generated via the mock of the type of the id field.

This is equivalent to an insert without any values.

Instead of providing a string for the field, an array can be used to traverse the graph:

store.get('Book', 123, ['owner', 'username']);

is the equivalent of:

const $owner = store.get('Book', 123, 'owner');
store.get($owner, 'username');

The set method accepts several different signatures:

Set a field value in the store for the given type, store key and field name:

store.set('Book', 123, 'title', 'some title');

store.get('Book', 123, 'title');
// returns: "some title"

If the field you're setting is a type (ie. Book or User), a reference can be provided:

const $user = store.get('User', 456);
store.set('Book', 123, 'owner', $user);

Just like get, a reference can be used as first argument to set values:

const $book = store.get('Book', 123);
store.set($book, 'title', 'a better title');

Multiple values can be passed using an object:

store.set('Book', 123, { title: 'The title', author: 'John Doe' });

// or using a reference
const $book = store.get('Book', 123);
store.set($book, { title: 'The title', author: 'John Doe' });

A nested object can be passed to deeply set values:

store.set('Book', 123, {
  owner: {
    name: 'that guy'
  }
})

The find method allows to store to be queried, but only fixtures. An array of references are returned.

store.find(typeName, predicate, opts)

Options

• fixturesOnly: Return only instances from fixtures (default: true).

Assuming the following fixtures:

const fixtures = {
  Book: [
    { id: 1, title: 'The amazing story' },
    { id: 2, title: 'A great story' },
    { id: 3, title: 'Greatest letters assembled into words' }
  ]
}

store.find('Book')
// returns: an array of reference to the `Book` fixtures

A predicate function can be also be passed:

store.find('Book', (book) => book.title.includes('story'));

Or a predicate object:

store.find('Book', { title: 'A great story' });

The following code tries to access fields that are not included in the fixtures, which will produce unstable results.

store.find('Book', (book) => book.author.includes('Shakespeare'));

This code attempts to get the author field. There is no guarantee that this field will exist, as it doesn't have values set in the fixtures.

findOne is like find, but only returns the first result, or null if no results.

Insert an instance into the store. Returns a reference to the inserted instance.

store.insert(typeName, values);
// returns: a reference to the inserted instance

Check if an instance or instance field exists in the store. Returns a boolean.

store.has(typeName, id, field);
// returns: boolean

This method will reset the store (and erase the cache).

store.reset();