# ❌ Running build in parallel with no dependency declaration
turbo run build --parallel

# If packages/ui hasn't finished compiling when apps/checkout starts,
# apps/checkout imports stale or missing type declarations.
# The build "succeeds" but produces broken output artifacts.

{
  "$schema": "https://turbo.build/schema.json",
  "tasks": {
    "build": {
      "dependsOn": ["^build"],
      "inputs": ["src/**", "package.json", "tsconfig.json"],
      "outputs": ["dist/**", ".next/**"]
    },
    "test": {
      "dependsOn": ["build"],
      "inputs": ["src/**", "tests/**", "package.json"],
      "outputs": []
    },
    "lint": {
      "dependsOn": [],
      "inputs": ["src/**", ".eslintrc*", "package.json"],
      "outputs": []
    },
    "type-check": {
      "dependsOn": ["^build"],
      "inputs": ["src/**", "tsconfig.json"],
      "outputs": []
    }
  }
}

// nx.json
{
  "targetDefaults": {
    "build": {
      "dependsOn": ["^build"],
      "inputs": ["production", "^production"],
      "outputs": ["{projectRoot}/dist"]
    },
    "test": {
      "dependsOn": ["build"],
      "inputs": ["default", "^production", "{workspaceRoot}/jest.config.ts"],
      "outputs": ["{projectRoot}/coverage"]
    }
  },
  "namedInputs": {
    "default": ["{projectRoot}/**/*", "sharedGlobals"],
    "production": ["default", "!{projectRoot}/**/*.spec.ts", "!{projectRoot}/jest.config.ts"],
    "sharedGlobals": ["{workspaceRoot}/.eslintrc.json"]
  }
}

Cache Key = SHA(
  source files (matched by inputs glob),
  package.json dependencies (resolved versions),
  global environment variables (declared in globalEnv),
  task name + CLI flags
)

// turbo.json
{
  "globalEnv": ["NODE_ENV", "CI", "DATABASE_URL"],
  "tasks": {
    "build": {
      "env": ["NEXT_PUBLIC_API_URL", "NEXT_PUBLIC_SENTRY_DSN"]
    }
  }
}

// nx.json
{
  "namedInputs": {
    "sharedGlobals": [
      { "env": "NODE_ENV" },
      { "env": "CI" }
    ]
  }
}

# Local cache — default, stored in .turbo/ on your machine
turbo run build

# Remote cache — Turborepo Cloud (Vercel)
turbo run build --remote-only

# Self-hosted remote cache (S3/R2/GCS compatible)
# Set in turbo.json:

{
  "remoteCache": {
    "enabled": true,
    "apiUrl": "https://your-turbo-cache.example.com"
  }
}

# Turborepo — run build only for packages changed since origin/main
turbo run build --filter=...[origin/main]

# Turborepo — run test only for packages that depend on changed packages (transitive)
turbo run test --filter=...[origin/main]...

# Nx — compute affected projects and run build
nx affected --target=build --base=origin/main --head=HEAD

# Nx — run test on all affected
nx affected --target=test --base=origin/main

# .github/workflows/ci.yml
name: CI

on:
  push:
    branches: [main]
  pull_request:
    branches: [main]

jobs:
  ci:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
        with:
          fetch-depth: 0  # Required for git history — affected analysis needs base branch

      - uses: pnpm/action-setup@v4
        with:
          version: 9

      - uses: actions/setup-node@v4
        with:
          node-version: 22
          cache: 'pnpm'

      - run: pnpm install --frozen-lockfile

      - name: Build & Test Affected
        run: pnpm turbo run build test lint --filter=...[origin/main]
        env:
          TURBO_TOKEN: ${{ secrets.TURBO_TOKEN }}  # Remote cache auth
          TURBO_TEAM: ${{ vars.TURBO_TEAM }}

// ❌ apps/checkout importing from apps/dashboard — a direct app-to-app import
import { UserSession } from '../../dashboard/src/auth/session'

// ❌ packages/ui importing from apps/checkout — a UI library depending on an app
import { CheckoutContext } from '../../apps/checkout/src/context'

// packages/ui/project.json
{
  "name": "@company/ui",
  "tags": ["scope:shared", "type:ui-library"]
}

// apps/checkout/project.json
{
  "name": "checkout",
  "tags": ["scope:checkout", "type:app"]
}

// packages/utils/project.json
{
  "name": "@company/utils",
  "tags": ["scope:shared", "type:utility"]
}

// .eslintrc.json (root)
{
  "rules": {
    "@nx/enforce-module-boundaries": [
      "error",
      {
        "enforceBuildableLibDependency": true,
        "allow": [],
        "depConstraints": [
          {
            "sourceTag": "type:app",
            "onlyDependOn": ["type:ui-library", "type:utility", "type:data-access"]
          },
          {
            "sourceTag": "type:ui-library",
            "onlyDependOn": ["type:utility"]
          },
          {
            "sourceTag": "scope:checkout",
            "notDependOn": ["scope:dashboard"]
          }
        ]
      }
    ]
  }
}

pnpm add -D eslint-plugin-boundaries -w

// .eslintrc.json
{
  "plugins": ["boundaries"],
  "settings": {
    "boundaries/elements": [
      { "type": "app",     "pattern": "apps/*" },
      { "type": "library", "pattern": "packages/ui" },
      { "type": "utility", "pattern": "packages/utils" },
      { "type": "types",   "pattern": "packages/types" }
    ]
  },
  "rules": {
    "boundaries/element-types": [
      "error",
      {
        "default": "disallow",
        "rules": [
          { "from": "app",     "allow": ["library", "utility", "types"] },
          { "from": "library", "allow": ["utility", "types"] },
          { "from": "utility", "allow": ["types"] }
        ]
      }
    ]
  }
}

# .github/workflows/ci.yml — add lint step
- name: Lint (includes boundary checks)
  run: pnpm turbo run lint --filter=...[origin/main]

ERROR  apps/checkout/src/OrderSummary.tsx
  Boundary violation: "app" cannot import from "app".
  Rule: sourceTag "type:app" cannot depend on "scope:dashboard".
  @nx/enforce-module-boundaries