API Reference

API Reference

Entry Points

InMemoryBigQuery

Static class for creating in-memory BigQuery instances.

Method	Description
Create(projectId, datasetId?, configureDataset?)	Creates a simple instance with optional dataset
Builder()	Returns a builder for complex configurations

InMemoryBigQueryBuilder

Fluent builder for multi-dataset setups.

Method	Description
WithProjectId(string)	Sets the GCP project ID
AddDataset(string, Action<InMemoryDatasetBuilder>?)	Adds a dataset
WithFaultInjector(Func<...>?)	Sets the fault injector
Build()	Builds and returns the result

InMemoryBigQueryResult

Result of creating an in-memory instance. Implements IDisposable.

Property	Tier	Description
Client	1 — Production-like	Real BigQueryClient backed by in-memory store
Store	2 — Test setup	Direct access to InMemoryDataStore
Handler	3 — Diagnostics	The FakeBigQueryHandler (logs, fault injection)

Method	Description
SetFaultInjector(Func<...>?)	Sets or clears fault injection
CreateReadClient()	Creates a BigQueryReadClient backed by the same in-memory store (Storage Read API)
Dispose()	Cleans up resources

Data Store

InMemoryDataStore

Property	Description
ProjectId	The GCP project ID
Datasets	ConcurrentDictionary<string, InMemoryDataset>
JsUdfEngine	Optional IJsUdfEngine for JavaScript UDF execution

Method	Description
ExportState()	Returns JSON string of all datasets, tables, and rows
ExportStateToFile(string path)	Exports state directly to a file
ImportState(string json)	Replaces all data from a JSON string
ImportStateFromFile(string path)	Imports state directly from a file
UseJsUdfs()	Registers the Jint JavaScript engine for LANGUAGE js UDFs (requires InMemoryEmulator.BigQuery.JsUdfs package)

InMemoryDataset

Property	Description
DatasetId	Dataset identifier
Tables	ConcurrentDictionary<string, InMemoryTable>
Description, FriendlyName, Location, Labels	Metadata
CreationTime, LastModifiedTime, Etag	Timestamps

InMemoryTable

Property	Description
TableId	Table identifier
Schema	TableSchema — the column definitions
RowCount	Number of rows
Description, FriendlyName, Labels	Metadata
CreationTime, LastModifiedTime, Etag	Timestamps

HTTP Layer

FakeBigQueryHandler

Extends HttpMessageHandler. Routes BigQuery REST API calls to the in-memory store.

Property	Description
FaultInjector	Optional delegate for simulating errors
RequestLog	ConcurrentBag<string> of all requests
QueryLog	ConcurrentBag<string> of all SQL queries

FakeBigQueryHttpClientFactory

Implements IHttpClientFactory for the Google API client pipeline.

DI Integration

ServiceCollectionExtensions

Method	Description
UseInMemoryBigQuery(Action<InMemoryBigQueryOptions>?)	Replaces BigQueryClient with in-memory

InMemoryBigQueryOptions

Property	Description
ProjectId	GCP project ID (default: "test-project")
Datasets	List of datasets to create
OnClientCreated	Callback after the client is created