repo-context

name	repo-context
description	Provides tech stack, package layout, conventions, and build commands for the iTwin/presentation monorepo. Use when: working on any package or app in this repo, planning changes, implementing features, reviewing code.

iTwin/presentation Repository Context

Overview

This is a pnpm monorepo orchestrated with Lage and versioned with Changesets.

Tech Stack

Area	Technology
Language	TypeScript (strict, ES2022, dual CJS/ESM builds)
UI	React 18, iTwinUI components, SCSS
Testing	Vitest
Linting	ESLint 9 (flat config), oxfmt for formatting
Platform	iTwin.js (iModels, ECSQL, Presentation APIs)
Reactive	RxJS
API docs	@itwin/build-tools (extract-api, docs)
Node	^24, pnpm 11

Packages

Package	Path	Purpose
@itwin/presentation-shared	packages/shared	Shared utilities and types
@itwin/presentation-core-interop	packages/core-interop	Interop layer with iTwin.js Core
@itwin/presentation-hierarchies	packages/hierarchies	Hierarchy building from iModels and other sources
@itwin/presentation-hierarchies-react	packages/hierarchies-react	React bindings for hierarchies
@itwin/presentation-components	packages/components	React components (lists, property grids, tables)
@itwin/unified-selection	packages/unified-selection	Unified selection storage
@itwin/unified-selection-react	packages/unified-selection-react	React bindings for unified selection
@itwin/presentation-opentelemetry	packages/opentelemetry	OpenTelemetry diagnostics integration
@itwin/presentation-models-tree	packages/models-tree	Models tree widget for internal testing
@itwin/presentation-test-utilities	packages/test-utilities	Internal test utilities

Apps

App	Path	Purpose
full-stack-tests	apps/full-stack-tests	Integration tests
test-app	apps/test-app	Sample app (frontend + backend)
performance-tests	apps/performance-tests	Benchmarks for hierarchies and unified selection
load-tests	apps/load-tests	Load testing

Key Conventions

• Packages produce dual CJS/ESM output via tsconfig.cjs.json / tsconfig.esm.json
• Public API is tracked via extract-api and .api.md report files in api/ folders
• Copyright headers are required on all source files (enforced by copyrightLinter.js):

  /*---------------------------------------------------------------------------------------------
   * Copyright (c) Bentley Systems, Incorporated. All rights reserved.
   * See LICENSE.md in the project root for license terms and full copyright notice.
   *--------------------------------------------------------------------------------------------*/
  

• User-visible changes to released packages require a changeset (pnpm change); packages with "private": true do not require a changeset.
• Build order is managed by Lage (lage build, dependencies via ^build)

Common Commands

Scope	Build	Test	Lint	Format
All (repo root)	pnpm build:all	pnpm cover:all	pnpm lint:all	pnpm format
Single package	pnpm build	pnpm test	pnpm lint	pnpm -w exec oxfmt --check .
Scoped build	pnpm lage build --to <package>	—	—	—
Format fix	pnpm format:fix	—	—	—