Finding tests

bun test decides which files to run as tests by matching their paths against a set of patterns.

Default Discovery Logic

By default, bun test recursively searches the project directory for files that match these patterns:

*.test.{js|jsx|ts|tsx|mjs|cjs|mts|cts} - Files ending with .test.js, .test.jsx, .test.ts, .test.tsx, .test.mjs, .test.cjs, .test.mts, or .test.cts
*_test.{js|jsx|ts|tsx|mjs|cjs|mts|cts} - Files ending with _test.js, _test.jsx, _test.ts, _test.tsx, _test.mjs, _test.cjs, _test.mts, or _test.cts
*.spec.{js|jsx|ts|tsx|mjs|cjs|mts|cts} - Files ending with .spec.js, .spec.jsx, .spec.ts, .spec.tsx, .spec.mjs, .spec.cjs, .spec.mts, or .spec.cts
*_spec.{js|jsx|ts|tsx|mjs|cjs|mts|cts} - Files ending with _spec.js, _spec.jsx, _spec.ts, _spec.tsx, _spec.mjs, _spec.cjs, _spec.mts, or _spec.cts

Exclusions

By default, bun test ignores:

node_modules directories
Hidden directories (those starting with a period .)
Files that don’t have JavaScript-like extensions (based on available loaders)

Customizing Test Discovery

Position Arguments as Filters

To filter which test files run, pass additional positional arguments to bun test:

terminal

bun test <filter> <filter> ...

Any test file with a path that contains one of the filters runs. Filters are substring matches, not glob patterns. For example, to run all tests in a utils directory:

terminal

bun test utils

This matches files like src/utils/string.test.ts and lib/utils/array_test.js.

Specifying Exact File Paths

To run a specific file in the test runner, make sure the path starts with ./ or / to distinguish it from a filter name:

terminal

bun test ./test/specific-file.test.ts

Filter by Test Name

To filter tests by name rather than file path, use the -t/--test-name-pattern flag with a regex pattern:

terminal

# run all tests with "addition" in the name
bun test --test-name-pattern addition

bun test matches the pattern against the test name prefixed with the labels of all its parent describe blocks, separated by spaces. For example, a test defined as:

math.test.ts

describe("Math", () => {
  describe("operations", () => {
    test("should add correctly", () => {
      // ...
    });
  });
});

For this test, bun test matches the pattern against the string “Math operations should add correctly”.

Changing the Root Directory

By default, Bun looks for test files starting from the current working directory. Change this with the root option in bunfig.toml:

bunfig.toml

[test]
root = "src"  # Only scan for tests in the src directory

Execution Order

Tests run in the following order:

Test files run sequentially, or across worker processes with --parallel
Within each file, tests run sequentially in definition order

Getting Started

Test Execution

Test Features

Specialized Testing

Reporting

Finding tests

Default Discovery Logic

Exclusions

Customizing Test Discovery

Position Arguments as Filters

Specifying Exact File Paths

Filter by Test Name

Changing the Root Directory

Execution Order

​Default Discovery Logic

​Exclusions

​Customizing Test Discovery

​Position Arguments as Filters

​Specifying Exact File Paths

​Filter by Test Name

​Changing the Root Directory

​Execution Order

Default Discovery Logic

Exclusions

Customizing Test Discovery

Position Arguments as Filters

Specifying Exact File Paths

Filter by Test Name

Changing the Root Directory

Execution Order