npm package: @fluidframework/test-runtime-utils
Description: Fluid runtime test utilities
Author: Microsoft and contributors
Latest version: 2.92.0

# @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.

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## 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:

```bash
npm i @fluidframework/test-runtime-utils
```

## Importing from this package

This package leverages [package.json exports](https://nodejs.org/api/packages.html#exports) to separate its APIs by support level.
For more information on the related support guarantees, see [API Support Levels](https://fluidframework.com/docs/build/releases-and-apitags/#api-support-levels).

To access the `public` ([SemVer](https://semver.org/)) 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>.

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## 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](../map/src/test/map.spec.ts), [directory](../map/src/test/directory.spec.ts), [matrix](../matrix/test/matrix.spec.ts).

### 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](../../framework/undo-redo/src/test/sequenceHandler.spec.ts), [snapshotVersion](../sequence/src/test/snapshotVersion.spec.ts).

### 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](../sequence/src/test/sharedString.spec.ts), [consensusOrderedCollection](../consensus-ordered-collection/src/test/consensusOrderedCollection.spec.ts), [consensusRegisterCollection](../consensus-register-collection/src/test/consensusRegisterCollection.spec.ts).

## 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](https://github.com/microsoft/FluidFramework/blob/main/packages/framework/azure-client/README.md#backed-locally) 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:

```javascript
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](https://github.com/microsoft/FluidFramework/blob/main/packages/framework/azure-client/README.md#backed-by-a-live-azure-fluid-relay-instance). Now, the configuration is using a real `tenantId` and the `InsecureTokenProvider` will need the matching `tenantKey` as provided during the service onboarding.

```javascript
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](https://github.com/microsoft/FluidFramework/blob/main/packages/framework/azure-client/src/AzureFunctionTokenProvider.ts) or your own implementation that fulfills the `ITokenProvider` interface as an alternative for production scenarios.

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## 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](https://github.com/nodejs/release#release-schedule), 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).
    -   Running Fluid in a Node.js environment with the `--no-experimental-fetch` flag is not supported.
-   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`](https://www.typescriptlang.org/tsconfig) options are supported.
    -   [`strictNullChecks`](https://www.typescriptlang.org/tsconfig) is required.
    -   [Configuration options deprecated in 5.0](https://github.com/microsoft/TypeScript/issues/51909) 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](https://webpack.js.org/) 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`](https://www.typescriptlang.org/tsconfig#moduleResolution) resolution should be used with TypeScript compilerOptions to follow the [Node.js v12+ ESM Resolution and Loading algorithm](https://nodejs.github.io/nodejs.dev/en/api/v20/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](https://jestjs.io/docs/ecmascript-modules) due to [unstable APIs in NodeJs](https://github.com/nodejs/node/issues/37648))

## Contribution Guidelines

There are many ways to [contribute](https://github.com/microsoft/FluidFramework/blob/main/CONTRIBUTING.md) to Fluid.

-   Participate in Q&A in our [GitHub Discussions](https://github.com/microsoft/FluidFramework/discussions).
-   [Submit bugs](https://github.com/microsoft/FluidFramework/issues) and help us verify fixes as they are checked in.
-   Review the [source code changes](https://github.com/microsoft/FluidFramework/pulls).
-   [Contribute bug fixes](https://github.com/microsoft/FluidFramework/blob/main/CONTRIBUTING.md).

Detailed instructions for working in the repo can be found in the [Wiki](https://github.com/microsoft/FluidFramework/wiki).

This project has adopted the [Microsoft Open Source Code of Conduct](https://opensource.microsoft.com/codeofconduct/).
For more information see the [Code of Conduct FAQ](https://opensource.microsoft.com/codeofconduct/faq/) or contact [opencode@microsoft.com](mailto:opencode@microsoft.com) 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](https://www.microsoft.com/trademarks).
Use of Microsoft trademarks or logos in modified versions of this project must not cause confusion or imply Microsoft sponsorship.

## Help

Not finding what you're looking for in this README? Check out [fluidframework.com](https://fluidframework.com/docs/).

Still not finding what you're looking for? Please [file an issue](https://github.com/microsoft/FluidFramework/wiki/Submitting-Bugs-and-Feature-Requests).

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](https://www.microsoft.com/en-us/legal/intellectualproperty/trademarks/usage/general).

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

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