@fluidframework/test-runtime-utils

Test utilities for the Fluid Framework Runtime. Include mock implementation of various runtime interfaces, as well as a mock logger for validating a particular log sequence.

Using Fluid Framework libraries

When taking a dependency on a Fluid Framework library's public APIs, we recommend using a ^ (caret) version range, such as ^1.3.4. While Fluid Framework libraries may use different ranges with interdependencies between other Fluid Framework libraries, library consumers should always prefer ^.

If using any of Fluid Framework's unstable APIs (for example, its beta APIs), we recommend using a more constrained version range, such as ~.

Installation

To get started, install the package by running the following command:

npm i @fluidframework/test-runtime-utils

Importing from this package

This package leverages package.json exports to separate its APIs by support level. For more information on the related support guarantees, see API Support Levels.

To access the public (SemVer) APIs, import via @fluidframework/test-runtime-utils like normal.

To access the legacy APIs, import via @fluidframework/test-runtime-utils/legacy.

API Documentation

API documentation for @fluidframework/test-runtime-utils is available at https://fluidframework.com/docs/apis/test-runtime-utils.

Writing unit test for a DDS

Unit tests for DDS fall under three broad categories. The following sections explain how to write a unit test for these categories using the mocks in this package.

Local unit tests

These are tests that do not require a remote DDS and so doesn't need the DDS to be connected. For example, testing that DDS APIs work correctly, local events are correctly fired, summary is generated and loaded correctly, etc. To write a unit test for these scenarios, follow these steps:

• Create a MockFluidDataStoreRuntime. The MockFluidDataStoreRuntime doesn't really do anything and is just used to create the DDS.
• Set the MockFluidDataStoreRuntime's local property to true. This will make sure that the ops generated by the DDS are not sent out.
• Use the MockFluidDataStoreRuntime to create the DDS.

Examples - map, directory, matrix.

Remote unit tests

These are tests that require a remote DDS and need the DDS to be connected. For example, testing that the op is correctly applied on a remote client, local op is correctly ack'd, remote events are correctly fired, etc. To write a unit test for these scenarios, follow these steps:

• Create a MockFluidDataStoreRuntime.
• Use the MockFluidDataStoreRuntime to create the DDS.
• We need the ability to process messages from multiple DDSes / clients. Create a MockContainerRuntimeFactory which stores messages from multiple clients and processes them when required.
• Create a MockContainerRuntime by calling createContainerRuntime on the MockContainerRuntimeFactory. MockContainerRuntime keeps track of the message and localOpMetadata until it is ack'd.
• We need to connect and attach the DDS to an IDeltaConnection so it can submit and process messages. Create a MockDeltaConnection by calling createDeltaConnection on the MockContainerRuntime.
• Use the MockDeltaConnection to connect the DDS.

Examples - sequenceHandler, snapshotVersion.

Reconnection unit tests

These are remote unit tests and in addition they need the capability to disconnect and reconnect the client. For example, testing that on reconnection - DDSes resubmits ops correctly, remote clients receive ops correctly, local clients ack the ops correctly, etc. To write a unit test for these scenarios, follow these steps:

• Follow all the steps from scenario 2 above with these changes:
  • Create MockContainerRuntimeFactoryForReconnection instead of MockContainerRuntimeFactory.
  • Create MockContainerRuntimeForReconnection instead of MockContainerRuntime.
• To disconnect the client, set connected = false on the MockContainerRuntimeForReconnection. This will trigger a delete of outstanding messages for this client on the MockContainerRuntimeFactoryForReconnection.
• To reconnect the client, set connection = true on the MockContainerRuntimeForReconnection. This will trigger a reSubmit call on the DDS to resubmit unack'd / unsent ops.

Examples - sharedString, consensusOrderedCollection, consensusRegisterCollection.

InsecureTokenProvider

The InsecureTokenProvider provides a class for locally generating JWT tokens, signed using a tenant key, that can be sent to Fluid services. These tokens will be used to authenticate and identify which user is sending operations from the client.

It takes in two parameters:

• tenantKey - Used for signing the token for use with the tenantId that we are attempting to connect to on the service
• user - Used to populate the current user's details in the audience currently editing the container

The AzureClient, from the @fluidframework/azure-client package, takes in a tokenProvider parameter as part of its constructor. This parameter can be fulfilled by using the InsecureTokenProvider that is exported here. However, it is advised to only use this for development or testing purposes as it risks exposing your Azure Fluid Relay service tenant key secret on your client side code.

Usage for Development with Local Tinylicious Instance

When using the AzureClient, you can configure it to run against a local Tinylicous instance. Please see the client's documentation on local development for more information on how to do so. In this scenario, the InsecureTokenProvider will take any value for its tenantKey parameter since we're working with a local Tinylicious instance that doesn't require any authentication. As such, we can create an instance of it like this:

const tokenProvider = new InsecureTokenProvider("fooBar", { id: "123", name: "Test User" });

Usage for Development with Azure Fluid Relay service

The AzureClient can also be configured to a deployed Azure Fluid Relay service instance as described here. Now, the configuration is using a real tenantId and the InsecureTokenProvider will need the matching tenantKey as provided during the service onboarding.

const tokenProvider = new InsecureTokenProvider("YOUR-TENANT-KEY-HERE", {
	id: "123",
	name: "Test User",
});

Again, this should ONLY be used for local development as including the tenant key in the client code risks allowing malicious users to sniff it from the client bundle. Please consider using the AzureFunctionTokenProvider or your own implementation that fulfills the ITokenProvider interface as an alternative for production scenarios.

Minimum Client Requirements

These are the platform requirements for the current version of Fluid Framework Client Packages. These requirements err on the side of being too strict since within a major version they can be relaxed over time, but not made stricter. For Long Term Support (LTS) versions this can require supporting these platforms for several years.

It is likely that other configurations will work, but they are not supported: if they stop working, we do not consider that a bug. If you would benefit from support for something not listed here, file an issue and the product team will evaluate your request. When making such a request please include if the configuration already works (and thus the request is just that it becomes officially supported), or if changes are required to get it working.

Supported Runtimes

• NodeJs ^20.10.0 except that we will drop support for it when NodeJs 20 loses its upstream support on 2026-04-30, and will support a newer LTS version of NodeJS (22) at least 1 year before 20 is end-of-life. This same policy applies to NodeJS 22 when it is end of life (2027-04-30).
• Modern browsers supporting the es2022 standard library: in response to asks we can add explicit support for using babel to polyfill to target specific standards or runtimes (meaning we can avoid/remove use of things that don't polyfill robustly, but otherwise target modern standards).

Supported Tools

• TypeScript 5.4:
  • All strict options are supported.
  • strictNullChecks is required.
  • Configuration options deprecated in 5.0 are not supported.
  • exactOptionalPropertyTypes is currently not fully supported. If used, narrowing members of Fluid Framework types types using in, Reflect.has, Object.hasOwn or Object.prototype.hasOwnProperty should be avoided as they may incorrectly exclude undefined from the possible values in some cases.
• webpack 5
  • We are not intending to be prescriptive about what bundler to use. Other bundlers which can handle ES Modules should work, but webpack is the only one we actively test.

Module Resolution

Node16, NodeNext, or Bundler resolution should be used with TypeScript compilerOptions to follow the Node.js v12+ ESM Resolution and Loading algorithm. Node10 resolution is not supported as it does not support Fluid Framework's API structuring pattern that is used to distinguish stable APIs from those that are in development.

Module Formats

• ES Modules: ES Modules are the preferred way to consume our client packages (including in NodeJs) and consuming our client packages from ES Modules is fully supported.

• CommonJs: Consuming our client packages as CommonJs is supported only in NodeJS and only for the cases listed below. This is done to accommodate some workflows without good ES Module support. If you have a workflow you would like included in this list, file an issue. Once this list of workflows motivating CommonJS support is empty, we may drop support for CommonJS one year after notice of the change is posted here.

  • Testing with Jest (which lacks stable ESM support due to unstable APIs in NodeJs)

Contribution Guidelines

There are many ways to contribute to Fluid.

• Participate in Q&A in our GitHub Discussions.
• Submit bugs and help us verify fixes as they are checked in.
• Review the source code changes.
• Contribute bug fixes.

Detailed instructions for working in the repo can be found in the Wiki.

This project has adopted the Microsoft Open Source Code of Conduct. For more information see the Code of Conduct FAQ or contact [e-mail] with any additional questions or comments.

This project may contain Microsoft trademarks or logos for Microsoft projects, products, or services. Use of these trademarks or logos must follow Microsoft’s Trademark & Brand Guidelines. Use of Microsoft trademarks or logos in modified versions of this project must not cause confusion or imply Microsoft sponsorship.

Help

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Thank you!

Trademark

This project may contain Microsoft trademarks or logos for Microsoft projects, products, or services.

Use of these trademarks or logos must follow Microsoft's Trademark & Brand Guidelines.

Use of Microsoft trademarks or logos in modified versions of this project must not cause confusion or imply Microsoft sponsorship.