message: docs(config): explains paths mapping
diff: @@ -50,6 +50,75 @@ module.exports = {
  }
  ```
  +## Paths mapping
  +
  +If you use ["baseUrl" asn "paths" options](https://www.typescriptlang.org/docs/handbook/module-resolution.html) in your `tsconfig` file, you should make sure the ["moduleNameMapper"](https://facebook.github.io/jest/docs/en/configuration.html#modulenamemapper-object-string-string) option in your Jest config is setup accordingly.
  +
  +TSJest provides a helper to transform the mapping from `tsconfig` to Jest config format, but it needs the `.js` version of the config.
  +
  +### Example:
  +
  +#### TypeScript config
  +
  +With the below config in your `tsconfig`:
  +```js
  +{
  + "compilerOptions": {
  + "paths": {
  + "@App/*": ["src/*"],
  + "lib/*": ["common/*"]
  + }
  + }
  +}
  +```
  +
  +#### Jest config (without helper):
  +
  +<div class="row"><div class="col-md-6" markdown="block">
  +
  +```js
  +// jest.config.js
  +module.exports = {
  + // [...]
  + moduleNameMapper: {
  + '^@App/(.*)$': '<rootDir>/src/$1',
  + '^lib/(.*)$': '<rootDir>/common/$1'
  + }
  +};
  +```
  +
  +</div><div class="col-md-6" markdown="block">
  +
  +```js
  +// OR package.json
  +{
  + // [...]
  + "jest": {
  + "moduleNameMapper": {
  + "^@App/(.*)$": "<rootDir>/src/$1",
  + "^lib/(.*)$": "<rootDir>/common/$1"
  + }
  + }
  +}
  +```
  +
  +</div></div>
  +
  +#### Jest config (with helper):
  +
  +```js
  +// jest.config.js
  +const { pathsToModuleNameMapper } = require('ts-jest');
  +// In the following statement, replace `./tsconfig` with the path to your `tsconfig` file
  +// which contains the path mapping (ie the `compilerOptions.paths` option):
  +const { compilerOptions } = require('./tsconfig');
  +
  +module.exports = {
  + // [...]
  + moduleNameMapper: pathsToModuleNameMapper(compilerOptions.paths /*, { prefix: '<rootDir>/' } */ )
  +};
  +```
  +
  ## TSJest options
  ### Introduction
  