Stringify content option

The stringifyContentPathRegex option has been kept for backward compatibility of __HTML_TRANSFORM__ It's a regular expression pattern used to match the path of file to be transformed. If it matches, the file will be exported as a module exporting its content.

Let's say for example that you have a file foo.ts which contains export default "bar", and your stringifyContentPathRegex is set to foo\\.ts$, the resulting module won't be the result of compiling foo.ts source, but instead it'll be a module which exports the string "export default \"bar\"".

CAUTION: Whatever file(s) you want to match with stringifyContentPathRegex pattern, you must ensure the Jest transform option pointing to ts-jest matches them. You may also have to add the extension(s) of this/those file(s) to moduleFileExtensions Jest option.

Example

In the jest.config.js version, you could do as in the package.json version of the config, but extending from the preset will ensure more compatibility without any changes when updating.

JavaScript

// jest.config.js
const { defaults: tsjPreset } = require('ts-jest/presets')

/** @type {import('ts-jest').JestConfigWithTsJest} */
module.exports = {
  // [...]
  moduleFileExtensions: [...tsjPreset.moduleFileExtensions, 'html'],
  transform: {
    ...tsjPreset.transform,
    '\\.html$': [
      'ts-jest',
      {
        stringifyContentPathRegex: /\.html$/,
      },
    ],
  },
}

TypeScript

// jest.config.ts
import type { JestConfigWithTsJest } from 'ts-jest'
import tsJestPresets from 'ts-jest/presets'

const jestConfig: JestConfigWithTsJest = {
  // [...]
  moduleFileExtensions: [...tsJestPresets.defaults.moduleFileExtensions, 'html'],
  transform: {
    ...tsJestPresets.defaults.transform,
    '\\.html$': [
      'ts-jest',
      {
        stringifyContentPathRegex: /\.html$/,
      },
    ],
  },
}

JSON

// package.json
{
  // [...]
  "jest": {
    "moduleFileExtensions": ["js", "ts", "html"],
    "transform": {
      "\\.(html|ts|js)$": [
        "ts-jest",
        {
          "stringifyContentPathRegex": "\\.html$"
        }
      ]
    }
  }
}