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Getting Started

This extension supports full jest features in vscode environment to make testing more intuitive and fun. It should work out-of-the-box for most common jest projects. To get started:

  1. Setup jest in your project if you haven't.
  2. install "Jest" extension in vscode.
  3. reload or restart vscode

If the extension can find the jest command, by default it will automatically run and monitor all tests in watch mode upon launch, and you should see tests, status, errors, coverage (if enabled) in TestExplorer and editors like this:

image

If you have a more sophisticated project configuration or prefer to run tests differently, fear not, the extension supports extensive customization settings. For example:

You can see the full features and learn more details in the How-To section. If you encounter an unexpected error, feel free to checkout the Troubleshooting or file an issue.

Happy testing!

Releases

All: Release Notes


Content


Features

Installation

Simply open Visual Studio Code, go to the extension view and search for "Jest". Alternatively, open Jest - Visual Studio Marketplace and click "Install".

For detailed releases and migration help, please see releases.

User Interface

This extension fully integrates with the VSCode testing framework, supporting both automatic and on-demand test runs. In addition to the standard VSCode Test Explorer interface, the extension provides additional UI elements to simplify the development workflow:

<img src="images/interface-6.1.0.png" alt="interface-6.1.0.png" width="1000"/> <br>
  1. Dynamic Run Mode: Run mode dictates the overall user experience, determining when tests should run, with or without coverage, error display style, etc. Different run modes may have different performance implications, particularly for larger projects.

    We realized that runMode preference could change even within a given project, for example developers prefer "watch" runMode when doing light code changes to ensure nothing breaks, may prefer the 'on-demand' mode during heavy test development for greater control over test execution. A static runMode config in "settings.json" is simply not sufficient. Therefore, we added the runMode quick switch so users can easily switch to different runMode without permanently modifying the "settings.json". <br>

  2. Interactive Test Run: Besides automatic test executions ("watch", "on-save"), users can initiate full test actions, such as run, debug, update/view snapshot, from both editor and Test Explorer through various UI components. <br>

  3. Test Output: The extension offers native jest run outputs in both the "TERMINAL" and "TEST RESULTS" panel. "TEST RESULTS" panel mainly displays test run output in execution order, while "TERMINAL" groups test output by workspace folder/virtual-folder, and also includes extension configuration details, quick-fix suggestions, etc. By default, the output appears when tests run, but this can be adjusted via the outputConfig setting. <br>

  4. Extension Status: Upon successful launch of the extension, the status bar shows the run status for the active folder, and the aggregated test status for the whole workspace. Clicking on each status reveals the associated output window.

How To?

How to set up the extension?

Hopefully, you don't have to do anything. If you can run jest from the terminal, you should be able to use this extension.

The extension will try to auto-config a jest command and debug config when needed. If the auto-config fails, or any non-test error occurred, users should see an quick-fix-chooser link in the output terminal to help resolving the issues.

For more details see the setup tool and the complete customization options in settings.

How to change runMode for the current session?

<a id='runmode-chooser'></a> To adjust the runMode during your current session:

  1. Click on the runMode buttons referenced in the User Interface section. This action will prompt a runMode chooser.

  2. Within the chooser, you can swiftly switch the runMode type, toggle coverage, opt for deferred mode, or directly edit the runMode within an editor.

<img src="images/runmode-chooser.png" alt="runMode Chooser Interface" width="800"/>
  1. Confirm your adjustments by clicking the "Apply" button located on the top right. Or discard changes with the "Return" button on the top left.

Note: Changes to runMode using the UI will apply only to the ongoing session. Upon restarting the extension or reloading the window, the runMode will revert to the value in settings.json. However, you can write the current runMode value to settings.json with command: "Jest: Save Current RunMode" via command palette.

For an in-depth understanding of each type and the available options, refer to runMode.

How to trigger a test run?

By default, the extension uses jest watch mode that automatically runs tests upon related file changes. In addition, users can also trigger individual tests/suites on-demand:

<img src="images/run-test.png" alt="run-test" width="800"/>
  1. trigger test runs via the gutter menu of each test and describe blocks.
  2. trigger test runs via the TestExplorer tree item's inline menu.
  3. trigger test runs via command palette, such as Jest: Run All Tests
  4. trigger test runs via the editor context menu: Jest: Run Related Tests

The extension will try to auto-config a jest runner, if it fails, you can try the quick-fix-chooser.

How to debug tests?

There are 2 ways to debug a specific test:

<img src="images/run-debug.png" alt="run-debug" width="800"/>
  1. via the editor gutter context menu
  2. via the test tree item inline menu

The extension will try to generate a debug config, but if you encounter a debug error or want to change the configuration, please see Customization - Debug Config.

How to use code coverage?


v6.3.0 and up

Test coverage can also be run interactively via the TestExplorer tree view, by clicking the "Run with Coverage" button.

<img src="images/test-coverage-explorer.png" alt="test-coverage-explorer" width="800"/>

v6.2.5 and below

[!Note] Note: The following describes the original test coverage feature, which remains available as of 2024/08/13. With the introduction of the new, more intuitive integration in v6.3.0, we plan to deprecate this feature soon. If you have any concerns or would like to share your thoughts on this change, please let us know.

Code coverage can be triggered via

  1. change runMode config via chooser or settings.
  2. Command Palette, select command like Jest: Toggle Coverage to activate or deactivate code coverage (see full list in commands.

The coverage stats will be displayed at the source code editor: summary at the top and inline coverage indicator based on the formatter selected.

<img src="images/coverage-screen-shot.png" alt="coverage-screen-shot" width="500"/>

To verify the coverage mode is on, one can check the runMode chooser or the status bar (see how to read the status bar)

Note: this extension supports both babel and v8 coverageProviders. However, please note the coverage might not be exactly the same, see facebook/jest#11188 for more details.

How to read coverage scheme and customize it

In addition to the coverage summary that is shown on the top of the file, each line will be marked by its coverage status according to the coverage formatter configured. There are 3 types of coverage you might see in your source code, distinguished by colors:

You can customize coverage start up behavior, style and colors, see customization for more details.

How to update and view snapshots

<img src="images/snapshot-menu.png" alt="snapshot-menu" width="800"/>

Users can update snapshots in any granularity from the context menu:

  1. in the TestExplorer tree view: Update snapshot for the workspace, folder, test file, or just a single test.
  2. in the Editor's gutter menu: Update and view the snapshot for a test block.

Snapshots are now fully supported for parameterized (test.each) and template-literal named tests.

How to use the extension with monorepo projects?

The extension supports monorepo projects with the following mechanisms:

  1. Single-root workspace: If all tests from monorepo packages can be run from a centralized location, such as project root, then a single-root workspace with proper "jest.jestCommandLine" and "jest.rootPath" setting should work.
  2. Multi-root workspace: If each monorepo package has its own local jest root and configuration, a multi-root workspaces is required. Users can use "jest.disabledWorkspaceFolders" to exclude the packages from jest run.
  3. Virtual folders: Starting from v6, users can also use virtual folders to configure monorepo packages from the root folder. See virtual folders for more details.

For option 1 and 2, the easiest way to setup the monorepo projects is to use the Setup Tool and choose Setup monorepo project.

Please note, a working jest environment is a prerequisite for this extension. If you are having problem running the tests from a terminal, please follow jest instruction to set it up first.

How to read the StatusBar?

StatusBar shows 2 types of information, illustrated below:

<img src="images/status-bar-overview.png" alt="snapshot-menu" width="500"/>
  1. Jest (folder-name): shows the mode and state of the "active" workspace folder or virtual folder (based on the active editor). As the hovering text showed, the "active" folder "react-ts" is in "watch" mode with coverage on.
  2. Jest-WS: shows the total test suite stats (pass, failed, unknown) for the whole workspace. Unknown test suites usually mean the test files are not yet run.

Hovering over the status items will show tooltips with descriptions; clicking on the items open the corresponding output window.

How to perform Quick-Fix?

<a id="quick-fix-chooser"></a> Upon non-test errors, such as jest command not found, the extension can help user fix common errors with quick fix:

<img src="images/quick-fix-chooser.png" alt="coverage-screen-shot" width="800"/>
  1. cmd + click on the quick fix link in the output terminal will open a quick-fix chooser.
  2. A quick-fix chooser listed the fixes and hints to help resolve common errors:
    • Customize Extensions: If you can run jest with CLI in the terminal but not with the extension, chances are you might need to configure the jest.jestCommandLine, jest.rootPath, monorepo settings, etc. This action will open the setup tools to continue.
    • Defer or Change Run Mode: If the project has not yet ready to run jest, you can use this action to defer the test run or change the runMode to on-demand mode. This action brings up a runMode chooser to continue.
    • Disable Extension: If you do not intend to run jest for this folder, you can choose this action to disable the extension. This action will set "jest.enable": false in the .vscode/settings.json file.
    • Help: If you are not sure what to do, you can choose this action to open the troubleshooting page.

How to see more debug info (self-diagnosis)?

It is sometimes helpful to see the actual command and shell environment spawned, as well as internal debug messages, to diagnose issues:

  1. Turn on the debug mode: set "jest.debugMode": true in .vscode/settings.json
  2. Open the developer console (via Help > Toggle Developer Tools menu), for example, to examine the PATH environment variables: look for the "spawn" log, expand the "options" object, expand the "env" property, all env variables (inherited from vscode process) should be there (view animation).

Customization

Settings

Users can use the following settings to tailor the extension for their environments.

settingdescriptiondefaultexample/notesavailable
Process
jestCommandLineThe command line to start jest testsundefined"jest.jestCommandLine": "npm test --" or "jest.jestCommandLine": "yarn test" or "jest.jestCommandLine": "node_modules/.bin/jest --config custom-config.js"
rootPathThe path to your frontend src folder"""jest.rootPath":"packages/app" or "jest.rootPath":"/apps/my-app"
nodeEnvAdd additional env variables to spawned jest processnull"jest.nodeEnv": {"PORT": "9800", "BAR":"true"}
shellshell (path or LoginShell) for executing jestnull"jest.shell": "/bin/bash" or "jest.shell": "powershell" or "jest.shell": {"path": "/bin/bash"; args: ["--login"]}
useDashedArgsDetermine if to use dashed arguments for jest processesundefined"jest.useDashedArgs":true>= v6.0.0
parserPluginOptionsConfigure babel parser pluginsnull"jest.parserPluginOptions": {decorators: 'legacy'}
virtualFoldersdefines multiple jest runs in a given vscode workspace folderundefined"jest.virtualFolders": "[{"name": "front-end", "rootPath': "packages/front-end"}, {"name": "back-end", "rootPath': "packages/back-end"} ]">= v6.0.0
useJest30instruct the extension to use jest 30 command line syntaxundefined"jest.useJest30": true>= v6.3.0
UX
outputConfig 💼Controls test output experience across the whole workspace.undefined"jest.outputConfig": "neutral" or "jest.outputConfig": {"revealOn": "run", "revealWithFocus": "terminal", "clearOnRun": 'terminal">= v6.1.0
runModeControls most test UX, including when tests should be run, output management, etcundefined"jest.runMode": "watch" or "jest.runMode": "on-demand" or "jest.runMode": {"type": "on-demand", "deferred": true}>= v6.1.0
:x: autoClearTerminalClear the terminal output at the start of any new test run.false"jest.autoClearTerminal": truev6.0.0 (replaced by outputConfig)
:x: testExplorerConfigure jest test explorernull{"showInlineError": "true"}< 6.1.0 (replaced by runMode)
:x: autoRunControls when and what tests should be runundefined"jest.autoRun": "off" or "jest.autoRun": "watch" or "jest.autoRun": {"watch": false, "onSave":"test-only"}< v6.1.0 (replaced by runMode)
:x: autoRevealOutputDetermine when to show test output"on-run""jest.autoRevealOutput": "on-exec-error"< v6.1.0 (replaced by outputConfig)
Coverage
:x: showCoverageOnLoadShow code coverage when extension startsfalse"jest.showCoverageOnLoad": true< v6.1.0 (replaced by runMode)
coverageFormatterDetermine the coverage overlay style"DefaultFormatter""jest.coverageFormatter": "GutterFormatter"
coverageColorsCoverage indicator color overrideundefined"jest.coverageColors": { "uncovered": "rgba(255,99,71, 0.2)", "partially-covered": "rgba(255,215,0, 0.2)"}
Misc
enableEnable/disable jest extension for the given workspace folder/virtual-foldertrue"jest.enable": false>=6.0.0
disabledWorkspaceFolders 💼Disabled workspace folders names in multi-root environment[]"jest.disabledWorkspaceFolders": ["package-a", "package-b"]
debugModeEnable debug mode to diagnose plugin issues. (see developer console)false"jest.debugMode": true
monitorLongRunmonitor long running tests based on given threshold in ms60000"jest.monitorLongRun": 120000

jestCommandLine

This should be the command users used to kick off the jest tests in the terminal. However, since the extension will append additional options at run time, please make sure the command line can pass along these options, which usually just means if you uses npm, add an additional "--" at the end (e.g. "npm run test --") if you haven't already in your script. It is recommended not to add the following options as they are managed by the extension: --watch, --watchAll, --coverage


rootPath

If your project doesn't live in the root of your repository, you may want to customize the jest.rootPath setting to enlighten the extension as to where to look. For instance: "jest.rootPath": "src/client-app" will direct the extension to use the src/client-app folder as the root for Jest.


coverageFormatter

There are 2 formatters to choose from:

<details> <summary> DefaultFormatter: high light uncovered and partially-covered code inline as well as on the right overview ruler. (this is the default)</summary>

coverage-DefaultFormatter.png

</details> <details> <summary>GutterFormatter: render coverage status in the gutter as well as the overview ruler.</summary>

coverage-GutterFormatter.png

</details>

(Note, there is an known issue in vscode (microsoft/vscode#5923) that gutter decorators could interfere with debug breakpoints visibility. Therefore, you probably want to disable coverage before debugging or switch to DefaultFormatter)


coverageColors

Besides the formatter, user can also customize the color via jest.coverageColors to change color for 3 coverage categories: "uncovered", "covered", or "partially-covered",

<details> <summary>example</summary>

for example:

"jest.coverageColors": {
  "uncovered": "rgba(255,99,71, 0.2)",
  "partially-covered": "rgba(255,215,0, 0.2)",
}

the default color scheme below, note the opacity might differ per formatter:

"jest.coverageColors": {
  "covered": "rgba(9, 156, 65, 0.4)",
  "uncovered": "rgba(121, 31, 10, 0.4)",
  "partially-covered": "rgba(235, 198, 52, 0.4)",
}
</details>

outputConfig

The outputConfig controls the Jest output experience by specifying when and where to create, display, and clear the output content. It supports 2 output panels: TEST RESULTS and TERMINAL. The TEST RESULTS panel displays test results in the order they were run, while the TERMINAL panel organizes outputs by workspace folder. TERMINAL panel also contains the non-test run outputs, such as quick-fix link, extension auto-config info, and tips.

Type Definitions

// typescript type definition
export interface JestRawOutputSetting {
  revealOn?: 'run' | 'error' | 'demand';
  revealWithFocus?: 'terminal' | 'test-results' | 'none';
  clearOnRun?: 'both' | 'terminal' | 'test-results' | 'none';
}
export type JestPredefinedOutputSetting = 'neutral' | 'terminal-based' | 'test-results-based';
export type JestOutputSetting = JestPredefinedOutputSetting | JestRawOutputSetting;

JestOutputSetting This setting can be one of the predefined types or a custom object.

<a id="outputconfig-conflict"></a> Handling Conflicts with "TEST RESULTS" panel setting

The Problem

The behavior of the "TEST RESULTS" panel is influenced by VSCode's native "testing.openTesting" setting. This can cause inconsistencies with your "jest.outputConfig" settings.

For instance, if you set "jest.outputConfig": {"revealWithFocus": "none"} to prevent automatic focus changes, but leave "testing.openTesting" at its default value of "openOnTestStart", the "TEST RESULTS" panel will still automatically switch focus when the tests are run via UI.

The Universal Solution

For a consistent Jest output experience, the simplest solution is to set "testing.openTesting": "neverOpen". This allows the extension to manage the "TEST RESULTS" and "TERMINAL" panels together using "jest.outputConfig" alone.

Further Customization

However, if you prefer "TEST RESULTS" and "TERMINAL" panels to behave differently and don't mind managing 2 settings yourself, you could play with different combinations.

For instance, if "testing.openTesting" is set to "openOnTestFailure", and you want your terminal panel to still reveal when any tests run, your setting would look like this: "jest.outputConfig": {revealWithFocus: "terminal"}.

Validation and Diagnosis

The extension features output config diagnosis information in the jest terminal, as well as the built-in conflict detection and quick fixes to assist with the transition.

<a id="default-output-focus"></a> Default Output Focus Behavior by RunMode When none of the output settings ("testing.openTesting" and "jest.outputConfig") are present, The default output behavior is determined by runMode:

runModeauto reveal "TEST RESULTS"auto reveal "TERMINAL"
"watch":heavy_multiplication_x::heavy_multiplication_x:
"on-save":heavy_multiplication_x::heavy_multiplication_x:
"on-demand":heavy_check_mark::heavy_multiplication_x:

Configuration Examples

[!NOTE] <a id="outputconfig-migration"></a> Migration Guide

Migrating to the new "jest.outputConfig" might require some manual adjustments, especially if you're working in a multi-root workspace. Here are some guidelines to help with the transition:

  1. Workspace Level vs Workspace-Folder Level: The new "jest.outputConfig" is a workspace-level setting, unlike legacy settings like "jest.autoClearTerminal" and "jest.autoRevealOutput", which are workspace-folder level settings.

  2. Backward Compatibility: If no "jest.outputConfig" is defined in your settings.json, the extension will attempt to generate a backward-compatible outputConfig in memory. This uses the "testing.openTesting" setting and any legacy settings ("jest.autoClearTerminal", "jest.autoRevealOutput") you might have. Note that this might only work for single-root workspaces.

  3. Customization Steps: In general it should work out of the box, but if you encounter any issues, here are some steps to help adjusting the output behavior:

    • Use the "Jest: Save Current Output Config" command from the command palette to update your settings.json. Then adjust it to fit your needs.
    • Fix warning if any: The save does not include "testing.openTesting", so you might see the conflict warning message. You can either use the "Quick Fix" action or adjust the settings.json manually (see handling conflict).
    • Finally, remove any deprecated settings.

By following these guidelines, you should be able to smoothly transition to using "jest.outputConfig".


runMode

The runMode controls test UX, determining when tests should run, and housing the common run-time toggles like coverage.

Type Definitions

// typescript types
interface JestRunModeOptions {
  runAllTestsOnStartup?: boolean;
  coverage?: boolean;
  deferred?: boolean;
  showInlineError?: boolean;
}
export type JestRunMode = JestRunModeOptions & (
  | { type: 'watch' }
  | { type: 'on-demand' }
  | { type: 'on-save'; testFileOnly?: boolean }
);

Predefined RunMode

The following are the predefined runMode configurations for convenience. They are mapped to the specified JestRunMode type at run time.

Predefined runModeDescriptionJestRunMode
"watch"run tests by watchman{type: "watch"}
"on-save"run tests when test or source files are saved{type: "on-save"}
"on-demand"run tests on-demand through UI{type: "on-demand"}
"deferred"defer test run and discovery until the first on-demand run{type: "on-demand", deferred: true}

Examples

runMode performance tradeoff <a id="runmode-tradeoff"></a>

Balancing performance, convenience and completeness is often challenging. The runMode offers a tool to fine-tune this equilibrium according to your preferences.

<img src="images/runmode-tradeoff.png" alt="runmode-tradeoff" width="400" style="border-radius: 10px;"/>

While the concepts of performance and automation are generally clear, "completeness" may require some elaboration:

  1. Test coverage might not be comprehensive since it only captures the tests that were executed.
  2. If you modify the source or test code, potential failures in other tests may remain hidden until they are explicitly run.
  3. Tests bearing dynamic names, like those using test.each with variables or template literals, won't be translated. As a result, they must be executed through higher-level constructs, such as describe blocks with static names or entire test suites.

[!NOTE] <a id="runmode-migration"></a> Migration Guide

Starting from v6.1.0, if no runMode is defined in settings.json, the extension will automatically generate one using legacy settings (autoRun, showCoverageOnLoad). To migrate, simply use the "Jest: Save Current RunMode" command from the command palette to update the setting, then remove the deprecated settings.


autoRun

[!WARNING] As of v6.1.0, autoRun will be replaced by <a href="#runmode">runMode</a>. For transition details, please refer to the <a href="#runmode-migration">runMode migration</a>.

AutoRun controls when tests should be executed automatically.

Performance and automation/completeness are often a trade-off. autoRun is the tool to fine-tune the balance, which is unique for every project and user.

<img src="images/autoRun-tradeoff.jpg" alt="autoRun-tradeoff" width="600"/>

Performance and automation are self-explanatory, "completeness" might not:

  1. test coverage might not be complete as it only includes the tests that ran.
  2. when changing the source or test code, you might not see all the tests broken until you run them explicitly.
  3. tests with dynamic names (test.each with variables, template-literals, etc.) will not be translated; therefore, they can only be run through parent blocks (describe-with-static-name or test suite, etc.).

There are 2 ways to change autoRun:

  1. Temporarily toggle autoRun on/off in TestExplorer
  2. Change "jest.autoRun" in settings.json file.

<a id="autorun-config">autoRun Configuration</a>

AutoRun =
  | "watch" | "off" | "legacy" | "on-save"
  | { watch: true, onStartup?: ["all-tests"] }
  | {
      watch: false,
      onStartup?: ["all-tests"],
      onSave?: "test-file" | "test-src-file",
    }

The string type are short-hand for the most common configurations:

Short Handdescriptionactual confignote
"watch"run jest in watch mode{"watch": true}the default mode
"off"turn off jest autoRun{"watch": false}this is the manual mode
"legacy"starting a full test-run followed by jest watch{"watch": true, "onStartup": ["all-tests"]}he default mode prior to v4.7
"on-save"run jest upon source or test file changes{"watch": false, "onSave": "test-src-file"}

User can also pass the actual config in the .vscode/settings.json, see more example below.

<details> <summary>example</summary> </details>

Please note, even when the autoRun is "off", the extension will still perform the usual setup upon start-up, such as checking jest env and parsing test blocks, so users can run test blocks manually. To turn off the extension completely for the given workspace, you can use jest.enable setting instead.


testExplorer

[!WARNING] As of v6.1.0, this setting has been folded into <a href="#runmode">runMode</a>. For transition details, please refer to the <a href="#runmode-migration">runMode migration</a>.

testExplorer = {showInlineError?: boolean}

shell

shell = string | LoginShell;

interface LoginShell 
{
  path: string;
  args: string[];
}

By default, jest command is executed in default shell ('cmd' for windows, '/bin/sh' for non-windows). Users can use the "jest.shell" setting to either pass the path of another shell (e.g. "/bin/zsh") or a LoginShell config, e.g. {"path": "/bin/bash", "args": ["--login"]})

Note the LoginShell is only applicable for non-windows platform and could cause a bit more overhead.

<a id="auto-recovery-login-shell"></a> Auto recovery with login shell Since v5, if detected shell env issue, such as node: command not found or npm: no such file or directory, the extension will fallback to a login shell to ensure tests can run correctly. If will try to auto generate a login shell configuration based on the jest.shell setting, otherwise, it will use the default bash login-shell. Currently supported auto-fallback shells are bash, zsh, fish.


monitorLongRun

monitorLongRun = number | 'off'

Default is "jest.monitorLongRun":60000 (1 minute)


autoRevealOutput

[!WARNING] As of v6.1.0, this setting has been folded into <a href="#outputconfig">outputConfig</a>. For transition details, please refer to the <a href="#outputconfig-migration">outputConfig migration</a>.

autoRevealOutput = "on-run" | "on-exec-error" | "off"

parserPluginOptions

parserPluginOptions = { decorators?: 
  | 'legacy' 
  | {
      decoratorsBeforeExport?: boolean;
      allowCallParenthesized?: boolean;
    }
  }

This extension uses babel to parse the test files. For decorators plugin options, it uses 'decorators', {decoratorsBeforeExport: true} by default, which can be customized with this setting. Examples:

"jest.parserPluginOptions": {"decorators": "legacy"}

"jest.parserPluginOptions": {"decorators": {"decoratorsBeforeExport": false}}

<a id="virtual-folders"></a>

virtualFolders

Much like a vscode workspace folder, which manages a runtime environment for a specific folder, a virtualFolder manages a custom Jest runtime environment. Each virtualFolder can have its own resource-level settings, such as jestCommandLine and rootPath.

You can configure multiple virtual folders within any given vscode workspace folder using the jest.virtualFolders setting. Here are a few common use cases and examples:

  1. Your project contains multiple jest configurations, such as unit test and integration test. While they run on the same set of source files, you want to run them separately and with different frequency: for instance, unit tests should always run automatically ("runMode": "watch") while the integration tests should only run on-demand ("runMode": "on-demand"):

    // settings.json for unit and integration test environments under the root folder:
    {
      "jest.virtualFolders": [
        {"name": "unit-tests", "jestCommandLine": "yarn test --config jest.unit.config.js", "runMode": "watch"},
        {"name": "integration-tests", "jestCommandLine": "yarn test --config jest.integration.config.js", "runMode": "on-demand"}
      ]
    }
    
  2. Your project is a monorepo and you want to run tests for each package separately. You can configure a virtual folder for each package:

    // settings.json for a monorepo project under the root folder:
    {
      "jest.virtualFolders": [
        {"name": "package1", "rootPath": "packages/package1"},
        {"name": "package2", "rootPath": "packages/package2"}
      ]
    }
    

Virtual Folders Inherit and Override Workspace Folder Settings Virtual folders inherit settings from the parent workspace but can override these settings as needed. For instance, you can set the runMode to "watch" in the workspace, but set it to "on-demand" for the virtual folders with many or expensive tests. This flexibility allows for granular control over the testing environments within a single workspace folder.

// settings.json in the "project" folder
{
  ...
  "jest.runMode": "watch",
  "jest.jestCommandLine": "yarn test",
  "jest.virtualFolders": [
    {"name": "unit-tests"},
    {"name": "integration-tests", , "runMode": "on-demand", "jestCommandLine": "yarn test --config=jest.integration.config.js"}
  ]
}

In this scenario, the "project" workspace will not run its own Jest environment but will instead spawn two separate Jest environments for "unit-tests" and "integration-tests".

<details> <summary> 🤔 VirtualFolders vs. Multi-root Workspace?</summary>

VirtualFolders vs. Multi-root Workspace While virtual folders are primarily designed to address the gap of supporting multiple test configurations for the same set of source files, they are also capable of supporting monorepo projects. Some developers might prefer this approach over traditional multi-root workspaces due to the simplified and centralized settings over individual package settings.

However, there are some key differences between virtual folders and multi-root workspaces to consider:

  1. Debug configurations for all virtual folders will appear in the same launch.json or debug configuration dropdown menu, each marked with the folder name for differentiation.
  2. Any changes to settings within the same VSCode folder will trigger a refresh or relaunch of all virtual folders within that folder.
  3. The StatusBar might display the status of multiple Jest runtime environments if the active editor document is shared by multiple virtual folders, such as a source code file that both unit and integration tests depend on.
  4. You might receive additional prompts to select target folders when running commands for shared files.
  5. virtualFolders only contains jest settings. If your project require non-jest settings from the package's own .vscode/settings.json (like in a multi-root workspace), then you are probably better off continue with multi-root workspace.
</details>

Debug Config

This extension looks for jest specific debug config ("vscode-jest-tests.[folder-name]" or "vscode-jest-tests.v2.[folder-name]") in the following order:

  1. workspace folder .vscode/launch.json.
  2. workspace xxx.code-workspace, if exists
  3. if none found, generated a debug config

The generated config should work for most standard jest or projects bootstrapped by create-react-app, however it might fall short for more sophisticated projects. Please use the setup tool to help you configure or edit the launch.json file manually.

There are many information online about how to setup vscode debug config for specific environments/frameworks, you might find the following helpful:

Debug Config v2

v4.3 introduces a "variable substitution" based config with name "vscode-jest-tests.v2.[folder-name]". The extension will merely substitute the jest variables in the config, without adding/removing anything else.

Currently supported variables:

<details> <summary>Examples</summary> </details>

Commands

This extension contributes the following commands and can be accessed via Command Palette:

commanddescriptionavailability
Jest: Start All Runnersstart or restart all jest runnersalways
Jest: Stop All Runnersstop all jest runnersalways
Jest: Toggle Coveragetoggle coverage mode for all runnersalways
Jest: Start Runner (Select Workspace)start or restart the jest runner for the selected workspacemulti-root workspace
Jest: Stop Runner (Select Workspace)stop jest runner for the selected workspacemulti-root workspace
Jest: Toggle Coverage (Select Workspace)toggle coverage mode for the selected workspacemulti-root workspace
Jest: Run All Testsrun all tests for all the workspacesalways
Jest: Run All Tests (Select Workspace)run all tests for the selected workspacemulti-root workspace
Jest: Run All Tests in Current Workspacerun all tests for the current workspace based on the active editoralways
Jest: Toggle Coverage for Current Workspacetoggle coverage mode for the current workspace based on the active editoralways
Jest: Save Current RunModeupdate "jest.runMode" in settings.json based on the current valuealways (>= 6.1.0)
Jest: Save Current Output Configupdate "jest.outputConfig" in settings.json based on the current valuealways (>= 6.1.0)
Jest: Setup Extensionstart the setup toolalways

In addition, TestExplorer also exposed many handy commands, see the full list by searching for testing in vscode keyboard shortcuts editor. One can assign/change keyboard shortcut to any of these commands, see vscode Key Bindings for more details.

Menu

User can trigger the following action from the text editor context-menu

menudescriptionkeyboard shortcut
Jest: Run Related Testsif in test file, run all tests in the file; if in source file, run all tests with dependency to the fileCtrl-Option-t (Mac) or Ctrl-Alt-t

Please see vscode Key Bindings if you want to change the keyboard shortcut.

Troubleshooting

Sorry you are having trouble with the extension. If your issue did not get resolved after checking out the how-to section and the tips below, feel free to ask the community, chances are some one else had a similar experience and could help resolving it.

Jest failed to run

If you can't run jest in the terminal, please reference jest configuration to setup accordingly.

If you can run jest manually in the terminal but the extension showed error like "xxx ended unexpectedly", following are the most common causes (see self-diagnosis if you need more debug info):

Feel free to try the quick-fix chooser, or check out the customization section to manually adjust the extension.

A few known failure scenarios:

Performance issue?

The extension should be a thin wrapper on top of the jest process, i.e., it shouldn't use much more resources than the jest process itself.

Having said that, we have definitely seen sluggish performance for some projects/users. The short answer is try changing runMode in the explorer, which should usually show noticeable improvement.

The long answer is a bit more complicated:

Intermittent errors for (npm/yarn/node) command not found during test run or debugging

This should only happen in Linux or MacOS, and is due to vscode not able to fully initialize the shell env when it starts up (more details here).

Alternatively, you can try the following methods if you prefer a non-login-shell solution:

I don't see "Jest" in the bottom status bar

This means the extension is not activated.

vscode will automatically activate the extension upon detecting any of the following patterns:

If none of the auto activation criteria is met, you can do the following to manually activate the extension:

What to do with "Long Running Tests Warning"

The extension monitor excessive test run with "jest.monitorLongRun" setting. By default if any runs exceed 60 seconds, a warning message will be shown.

You can also turn off the monitor or change the threshold with "jest.monitorLongRun" to meet your needs.

The tests and status do not match or some tests showing question marks unexpectedly?

If your test file happen to have parameterized tests, i.e. test.each variations, please make sure you have jest version >= 26.5.

If the above did not resolve your issue, please see the self-diagnosis to show more insight of why the test and result could not be matched.

Want to Contribute?

Thanks for considering! Check here for useful tips and guidelines.

License

vscode-jest is MIT licensed.