Variable configConst

Type Declaration

• tsconfig: { description: string; type: string }

  Path to the tsconfig.json file containing project settings provided to ts-node when running tests.

  Similar to the --project option to ts-node. Sets the TS_NODE_PROJECT environment variable.

  If this is a relative directory, then it is resolved against the project root directory.

  Defaults to the first of these files that are found in the project root directory:

  • tsconfig.tap.json
  • tsconfig.test.json
  • tsconfig.spec.json
  • tsconfig.json

• type-strip-only: { description: string; type: string }

  flag

  Do not compile OR typecheck test files, and instead, opt into Node's built-in type stripping behavior.

  Note that this limits the TypeScript features that can be used, but it is the fastest and most responsive approach, because it does not require a build step of any kind.

  This flag supercedes typecheck and tsconfig, because no compilation is performed.

  Only supported on Node 22 and higher.

  On Node 22, adds the --experimental-strip-types flag. On Node 23 and higher, this is supported by default.

  Adds a --no-warnings flag on all Node versions, to avoid the prevalance of warnings about type stripping being an experimental feature.

• typecheck: { description: string; type: string }

  flag

  Type-check test files, in addition to transpiling and running them.

  This defaults to false, even though type checking your tests is generally a good idea. Unfortunately, it is also often considerably slower, adding as much as 500-750ms to each test suite file, which can be painful if you have a lot of tests. In large project folders, the effect can be even more pronounced.

  It is a good idea to enable this in CI environments, where test speed is less of an ergonomic drawback.

  The "skipLibCheck": true option in tsconfig will also speed things up a bit, at the expense of some type safety.

  Note that even if you pre-compile your tests, they will still be subject to type checking if "allowJs": true is set in your tsconfig.