Comment Directives
The comment directives are single-line comments that serve as inline configuration for the test runner.
This feature is available since TSTyche 4.0.
Usage
Only a single-line comment is considered to be a directive if its text starts with @tstyche
namespace followed by the directive keyword. An argument must be provided if a directive requires it. Optionally, a note can be added after two or more hyphens.
// @tstyche if { target: [">=5.7"] } -- Only when TypeScript 5.7 or above is used
The argument text is parsed as a JSON string, but unquoted keys, single quotes or trailing commas are allowed. This means you can style the arguments just like the rest of the code.
Directives
The scope of a directive can be:
- the whole test file (use it at the top of the file),
- a single assertion or a test helper (place it above any
expect()
,test()
ordescribe()
), - or both of the above.
When a comment directive is used in the wrong scope, it holds no special meaning.
// @tstyche if
- Scope: a single assertion or a test helper, or the whole test file
- Argument type:
{ target: Array<string> }
Run an expect()
, test()
or describe()
only when the specified condition matches.
import { , } from "tstyche";
function (: unknown): is {
return instanceof ;
}
("isUint8Array", () => {
const : <unknown> = [];
// @tstyche if { target: [">=5.7"] } -- Before TypeScript 5.7, 'Uint8Array' was not generic
(.())..<<<>>>();
// @tstyche if { target: ["<5.7"] }
(.())..<<>>();
});
If this directive is used at the top of the file, the whole test file would run only when the specified condition matches.
// @tstyche template
- Scope: the whole test file
Marks a test file as a template. When the directive is found, the default export of a file is interpreted as a type test text.
For example, the following:
// @tstyche template -- For documentation, see: https://tstyche.org/guides/template-test-files
let = `import { expect, test } from "tstyche";
`;
for (const of ["string", "number"]) {
+= `test("is ${} a string?", () => {
expect<${}>().type.toBe<string>();
});
`;
}
export default ;
is interpreted as:
import { , } from "tstyche";
("is string a string?", () => {
<string>()..<string>();
});
("is number a string?", () => {
<number>()..<string>();
});
To learn more, see the Template Test Files page.