Release Notes

This page lists breaking changes and notable new features. Please be sure to read the release notes before upgrading from previous version.

TSTyche 7.0

TSTyche 7.0 ships with the new .toBeInstantiableWith() matcher and redesigned tsconfig option.

npm add -D tstyche@next

yarn add -D tstyche@next

pnpm add -D tstyche@next

Matchers

.toBeInstantiableWith()

The .toBeInstantiableWith() matcher checks if a generic is instantiable with the given type arguments.

import { type _, expect } from "tstyche";
 
interface Matchers<R, T = unknown> {
  [key: string]: (expected: T) => R;
}
 
expect<Matchers<_>>().type.toBeInstantiableWith<[void]>();
expect<Matchers<_>>().type.toBeInstantiableWith<[void, string]>();
 
expect<Matchers<_>>().type.not.toBeInstantiableWith<[]>();

This matcher works with generic interfaces, type aliases, classes and functions:

import { expect } from "tstyche";
 
function map<T, U>(array: Array<T>, transform: (item: T) => U): Array<U> {
  return array.map(transform);
}
 
expect(map).type.toBeInstantiableWith<[string, number]>();
expect(map).type.not.toBeInstantiableWith<[string]>();

Configuration

checkSuppressedErrors

Checking for errors suppressed by @ts-expect-error directives in multi-line comments is now enabled.

This is useful in contexts where single line comments are not supported. For example, in TSX files:

function ProfileCard(props: { userName: string }) {
  return <>{props.userName}</>;
}
 
<>
  {/* @ts-expect-error  Type 'boolean' is not assignable to type 'string'. */}
  <ProfileCard userName={true} />
</>;

rootPath

Now the root directory is always set to the current directory. Or, when the --root command line option is set, to the provided path.

tsconfig

baseline is the new name of ignore.

{
- "tsconfig": "ignore"
+ "tsconfig": "baseline"
}

Inline JSON

TSConfig can be provided as an inline JSON string. The implementation creates a synthetic TSConfig file in the root directory.

Configuration file:

{
  "tsconfig": "{\"extends\":\"./tsconfig.json\",\"compilerOptions\":{\"lib\":[\"es2020\"]},\"include\":[\"**/*\"]}"
}

Command line:

tstyche --tsconfig '{"extends":"./tsconfig.json","compilerOptions":{"lib":["es2020"]},"include":["**/*"]}'

Programmatic Usage