Project structure

O3 consists of both monorepos and standalone repositories. Monorepos are used to group domain-specific packages that are related to each other. For example, patient management concerns such as registration and search live in the Patient Management (opens in a new tab) monorepo. Standalone repositories are used for single-purpose packages that are not related to other packages. For example, the Form Builder (opens in a new tab) package is a standalone repository that contains functionality for building and managing form schemas.

Monorepos should contain domain-specific packages that are related to each other. For example, patient management concerns such as registration and search live in the openmrs-esm-patient-management monorepo.
Shared configuration files should generally exist at the root of the monorepo directory. These include:
- .eslintignore - ESLint ignore file
- .eslintrc - ESLint configuration file
- .prettier.config.js - Prettier configuration file
- .prettierignore - Prettier ignore file
- .yarnrc.yml - Yarn configuration file
- tsconfig.json - Root TypeScript configuration file
- turbo.json - Turbo configuration file
- package.json - Root package manifest file. This:
  - Defines workspace-level scripts for the monorepo
  - Sets the private: true property which prevents the monorepo from accidentally being published to the npm registry.
  - Declares shared dependencies for the monorepo in the peerDependencies and dependencies properties.
  - Defines the workspaces property which tells Yarn how to find the workspaces in the monorepo.
A typical convention is to place configuration files for the i18next parser, test utilities, and the Jest test setup file in a tools directory at the root of the monorepo:
- tools/i18next-parser.config.js - i18next parser configuration file
- tools/setupTests.ts - Jest test setup file
- tools/test-utils.tsx - Test utilities
Configuration files you'd expect to find at the root of each package in the monorepo include:
- package.json - Manifest file for the package. This is where you should put scripts for the package. Importantly, this file doesn't have the private property, meaning the package can be published to the npm registry.
- tsconfig.json - TypeScript configuration file that extends the root TypeScript configuration file.
- jest.config.ts - Jest configuration file that extends the root Jest configuration file.
- webpack.config.js - Webpack configuration file that extends the root Webpack configuration file.
Place e2e tests in the e2e/specs directory at the root of your repository.
Place test mocks in the top level __mocks__ directory at the root of your repository. Mocks should be named after the module they are mocking. For example, if you have a mock with data for the @openmrs/esm-patient-allergies module, your mock should be named allergies.mock.ts. The root-level Typescript configuration file will automatically pick up any mocks in the __mocks__ directory courtesy of the paths configuration in the root tsconfig.json file:
```
"paths": {
  "__mocks__": ["./__mocks__"],
  "tools": ["./tools"]
},
```
This means you can import the mock in your tests using a path alias:
```
// TypeScript will automatically resolve the path to the mock
import { mockAllergy } from '__mocks__';
```
TypeScript automatically resolves the path to the top-level tools directory using the same mechanism. This means you can also import test utilities from the tools directory using a path alias:
```
// TypeScript will automatically resolve the path to the tools directory
import { waitForLoadingToFinish } from 'tools';
```

Introduction Code organization