go-firestarter

go-firestarter an emulator for Google Firestore. It stores documents and collections in memory and performs queries against that in-memory store.

go-firestarter was forked from go-mockfs (https://github.com/weathersource/go-mockfs). go-mockfs is a low level mock for Google Firestore matching the request's protobuf message and returning a response protofbuf message. go-firestarter differs by implementing the logic for creating/updating documents and querying.

Missing Functionality

• NULL/NaN value handling
• Order By on field with different types between documents
  • https://firebase.google.com/docs/firestore/manage-data/data-types#value_type_ordering
• Order By existence
  • https://firebase.google.com/docs/firestore/query-data/order-limit-data#limitations
• Various limitations/edge-cases
  • https://firebase.google.com/docs/firestore/query-data/queries#query_limitations
• Transactions
• Update off of deprecated import
• Aggregation queries
  • https://firebase.google.com/docs/firestore/query-data/aggregation-queries
• Vector types

How To Use?

client_test.go (https://github.com/ISBX/go-firestarter/blob/master/client_test.go) is a good reference.

An example:

ctx := context.Background()
client, srv, err := New()
assert.Nil(t, err)
defer srv.Close()

srv.LoadFromJSONFile("test.json")

docSnaps, err := client.Collection("collection-1").Where("field1", "==", "value-1-2-1").Documents(ctx).GetAll()
assert.Nil(t, err)

assert.Len(t, docSnaps, 1)
assert.Equal(t, "document-1-2", docSnaps[0].Ref.ID)

func (s *MockServer) LoadFromJSONFile(filePath string) error

Since JSON types only cover a subset of Firestore types, LoadFromJSONFile will parse strings for Timestamps and Bytes.

• If the string is a RFC3339 (https://pkg.go.dev/time#pkg-constants), the value will be stored as a time.Time internally and returned as a pb.Value_TimestampValue.
• If the string is a data URL, the value will be stored as a []byte and returned as a pb.Value_BytesValue.

test.json (https://github.com/ISBX/go-firestarter/blob/master/test.json) has a few examples.