SmartTest Install SmartTest

Only the testsa change reaches

SmartTest follows each change through a dependency graph of your TypeScript or JavaScript repository, down to the method, and runs only the tests it reaches with Jest, Vitest, node --test, Playwright, Cypress or Angular. Python and PHP are in preview.

Install SmartTest How it decides
◇ git · HEAD…working tree · 1 changed file · mode balanced · analysis complete
modified src/modules/auth/TokenManager.ts implementation
SELECTED 3
SKIPPED 4 · not run
□tests/unit/modules/auth/AuthController.test.ts
□tests/unit/modules/catalog/CatalogService.test.ts
□tests/unit/modules/users/UserService.test.ts
□tests/unit/shared/validators/EmailValidator.test.ts

3 of 7 test files run

Switch the edits above the panel on and off. The panel shows what SmartTest selects in the example project from this repository, computed by SmartTest itself.

Select a test to see the path from the change to it.

Balanced mode

The default for pull requests and hooks. Every change counts, and a test behind an import SmartTest cannot resolve is selected on its own instead of being ruled out.

Rules can only make the mode stricter. A file marked critical upgrades the whole decision to SAFE.

Safety mode

What happens on a commit

  1. First, the change. SmartTest reads what changed from Git: the staged files in a pre-commit hook, the working tree, a branch against its merge-base, or any commit range. Without Git it compares local snapshots of the project.

    ◇ git · HEAD…index (staged) · 1 changed file(s) · mode balanced
    modified src/modules/auth/TokenManager.ts implementation

  2. Then, the declarations. Each changed line is mapped to the method, function or class around it and classified as comment, formatting, implementation, signature or exported API. An edit inside verify is a change to TokenManager.verify, not to every user of the file.

    changed unit src/modules/auth/TokenManager.ts#TokenManager.verify
    not changed TokenManager.issue · the class shell · the file's module code

  3. Then, the graph. From the changed method SmartTest walks backwards to every test that can reach it, through imports, re-exports, barrels, inheritance, CommonJS, path aliases and workspace packages. Environment keys, Prisma models, translation keys and files read with fs are nodes too, so a change to one key reaches only the code that reads it.

    TokenManager.verify → AuthService.validateToken → authenticate → protectedRoute → test/routes/ProtectedRoutes.test.ts
    i18n:greeting → src/greet.ts#greet → tests/greet.test.ts

  4. Then, what it cannot see. An import it cannot resolve is never treated as unrelated: the tests behind it run. When smarttest trace has recorded which functions each test ran, a test that can reach the change on paper but never ran the changed code is skipped, with the date of the trace as its reason.

    SKIPPED (not run) tests/price.test.ts
    • Reachable statically, but its trace (2026-10-29) never ran the changed code

  5. Last, your runner. The selected tests run through the project's own runner and its configuration: Jest, Vitest, node --test, Playwright, Cypress, Angular, pytest or PHPUnit. The report lists every skipped test as not run, never as passed.

    SmartTest HTML report: 1 of 15 test files selected, the translation test failed on the changed key, 14 test files skipped by selection and not run.
    The HTML report after a translation key changed in the edges-vitest fixture: one test selected, its failure caught, fourteen not run.

Works with what you have

No plugin in your test runner and no change to your tests. SmartTest asks each runner which files it collects and runs them with your config.

Jestwith your jest.config
Vitestcustom config names too
node --testdirectories and globs
Playwrightprojects, setup and live specs
Cypressspecs mapped to pages
Angulartemplates, styles, ng test
pytest, PHPUnitPython and PHP, in preview
Gitor local snapshots
TypeScriptpath aliases, project references
CommonJSmodule.exports per symbol
pnpm, npm, Yarnworkspaces, or none at all
Prismamodels and enums
Waspoperations in main.wasp.ts
react-i18nextkeys per namespace

Measured ona real repository

LeadsIt has six projects, no root manifest and three runners. It replaced its pre-commit test steps with smarttest run --staged. These are its numbers with SmartTest 0.5.0.

SmartTest HTML report for LeadsIt: 100 of 100 test files selected after a lockfile change, 706 tests passed, 0 failed, 7.7 seconds.
A lockfile change runs everything by design: 706 passed in 7.7 s.
706
tests, the same results through SmartTest as through the three runners
0
missed failures in 52 replayed commits, every miss re-checked on the parent commit
17
percent of test files run over 40 commits sampled from the last 200
63
percent of full-run time saved on the same commits, analysis included
23
seconds to trace all 100 test files across Jest, Vitest and node --test
7
.7
seconds for the full suite through SmartTest

Documentation

Start with getting started, then read how selection works. Every page is also in the repository under documentation/.

Start

Guides

Concepts

Reference

Results

Project

SmartTest HTML report in the light theme: one failing test selected and fourteen not run. SmartTest HTML report in the light theme for LeadsIt: 706 tests passed.

Try it on your repository

SmartTest is not on npm yet. These commands build it from the repository, install it in your project and preview the setup. Nothing is written until you run init --yes.

Set up SmartTest

Node.js 22.12 or newer · Jest, Vitest, node --test, Playwright, Cypress, Angular · Python and PHP in preview

cd ~/code/my-app
npm install -D @tkmremi/smarttest
npx smarttest init --dry-run
npx smarttest init --yes