name: nx-monorepo-generator
description: Use when adding Jest testing configuration to Nx projects, running nx g @nx/jest:configuration, setting up testing infrastructure, or troubleshooting tests that fail after running the Jest generator. Ensures proper TypeScript moduleResolution (nodenext), testing enhancement libraries (jest-dom, user-event, MSW), and monorepo pattern adherence. Triggers: "add tests", "setup Jest", "configure testing", "Jest not working", "moduleResolution error", "tests failing after generator"
Nx Monorepo Generator - Jest Configuration Workflow
The Nx Jest generator produces defaults that conflict with this workspace's standards. This skill ensures all mandatory post-generation fixes are applied.
Phase 1: Determine Project Type
Identify the project type before generating:
| Type |
Examples |
Testing Needs |
| UI |
web apps, mobile |
Full stack: jest-dom, user-event, MSW |
| Node |
server, APIs |
jest-dom + conditional MSW |
| Logic |
schemas, utils |
Basic Jest only |
How to identify:
- Check
project.json executors (React/Next.js = UI, Node = server)
- Schema/utility libraries = Logic
- When uncertain, ask the user
Phase 2: Generate Configuration
pnpm exec nx g @nx/jest:configuration <project-name>
Creates: jest.config.ts, tsconfig.spec.json, updates project.json
Warning: Generated config has incorrect defaults - proceed to Phase 3.
Phase 3: Post-Generation Fixes
Execute ALL applicable steps. See references/post-gen-checklist.md for full details.
| Step |
UI |
Node |
Logic |
Script |
| Install testing libs |
✅ |
✅ |
❌ |
scripts/install-testing-libs.sh |
| Create jest.setup.ts |
✅ |
❌ |
❌ |
Manual |
| Update jest.config.ts |
✅ |
❌ |
❌ |
Manual |
| Fix moduleResolution |
✅ |
✅ |
✅ |
scripts/fix-tsconfig-spec.sh |
| Verify Jest types |
✅ |
✅ |
✅ |
scripts/validate-jest-config.sh |
| Clean production config |
✅ |
✅ |
✅ |
scripts/validate-jest-config.sh |
Critical Fix: TypeScript moduleResolution
In tsconfig.spec.json, change:
"module": "commonjs" → "module": "nodenext""moduleResolution": "node10" → "moduleResolution": "nodenext"
Why: Workspace uses customConditions requiring modern module resolution.
Phase 4: Validation
# Automated validation
scripts/validate-jest-config.sh <project-path>
# Run tests
pnpm exec nx run <project-name>:test
Success indicators:
- ✅ Tests run without TypeScript errors
- ✅ No module resolution warnings
- ✅ Coverage reports generate correctly
References
references/post-gen-checklist.md - Step-by-step checklist with code examplesreferences/jest-config-patterns.md - Configuration structure and rationalereferences/testing-standards.md - user-event, MSW, jest-dom patterns
Scripts
scripts/validate-jest-config.sh <path> - Validate configuration against standardsscripts/install-testing-libs.sh <type> <path> - Install testing packages by project typescripts/fix-tsconfig-spec.sh <path> - Auto-fix moduleResolution settings
Key Principle
Generated code rarely matches monorepo patterns. Post-generation fixes are MANDATORY. This skill ensures consistency and prevents pattern drift that causes mysterious failures.
1---2name: nx-monorepo-generator3description: Use when adding Jest testing configuration to Nx projects, running `nx g @nx/jest:configuration`, setting up testing infrastructure, or troubleshooting tests that fail after running the Jest generator4---5
6---
7name: nx-monorepo-generator
8description: Use when adding Jest testing configuration to Nx projects, running `nx g @nx/jest:configuration`, setting up testing infrastructure, or troubleshooting tests that fail after running the Jest generator. Ensures proper TypeScript moduleResolution (nodenext), testing enhancement libraries (jest-dom, user-event, MSW), and monorepo pattern adherence. Triggers: "add tests", "setup Jest", "configure testing", "Jest not working", "moduleResolution error", "tests failing after generator"
9---
10
11# Nx Monorepo Generator - Jest Configuration Workflow
12
13The Nx Jest generator produces defaults that conflict with this workspace's standards. This skill ensures all mandatory post-generation fixes are applied.
14
15## Phase 1: Determine Project Type
16
17Identify the project type before generating:
18
19| Type | Examples | Testing Needs |
20|------|----------|---------------|
21| **UI** | web apps, mobile | Full stack: jest-dom, user-event, MSW |
22| **Node** | server, APIs | jest-dom + conditional MSW |
23| **Logic** | schemas, utils | Basic Jest only |
24
25**How to identify**:
26- Check `project.json` executors (React/Next.js = UI, Node = server)
27- Schema/utility libraries = Logic
28- When uncertain, ask the user
29
30## Phase 2: Generate Configuration
31
32```bash
33pnpm exec nx g @nx/jest:configuration <project-name>
34```
35
36Creates: `jest.config.ts`, `tsconfig.spec.json`, updates `project.json`
37
38**Warning**: Generated config has incorrect defaults - proceed to Phase 3.
39
40## Phase 3: Post-Generation Fixes
41
42Execute ALL applicable steps. See `references/post-gen-checklist.md` for full details.
43
44| Step | UI | Node | Logic | Script |
45|------|:--:|:----:|:-----:|--------|
46| Install testing libs | ✅ | ✅ | ❌ | `scripts/install-testing-libs.sh` |
47| Create jest.setup.ts | ✅ | ❌ | ❌ | Manual |
48| Update jest.config.ts | ✅ | ❌ | ❌ | Manual |
49| Fix moduleResolution | ✅ | ✅ | ✅ | `scripts/fix-tsconfig-spec.sh` |
50| Verify Jest types | ✅ | ✅ | ✅ | `scripts/validate-jest-config.sh` |
51| Clean production config | ✅ | ✅ | ✅ | `scripts/validate-jest-config.sh` |
52
53### Critical Fix: TypeScript moduleResolution
54
55In `tsconfig.spec.json`, change:
56- `"module": "commonjs"` → `"module": "nodenext"`
57- `"moduleResolution": "node10"` → `"moduleResolution": "nodenext"`
58
59**Why**: Workspace uses `customConditions` requiring modern module resolution.
60
61## Phase 4: Validation
62
63```bash
64# Automated validation
65scripts/validate-jest-config.sh <project-path>
66
67# Run tests
68pnpm exec nx run <project-name>:test
69```
70
71**Success indicators**:
72- ✅ Tests run without TypeScript errors
73- ✅ No module resolution warnings
74- ✅ Coverage reports generate correctly
75
76## References
77
78- `references/post-gen-checklist.md` - Step-by-step checklist with code examples
79- `references/jest-config-patterns.md` - Configuration structure and rationale
80- `references/testing-standards.md` - user-event, MSW, jest-dom patterns
81
82## Scripts
83
84- `scripts/validate-jest-config.sh <path>` - Validate configuration against standards
85- `scripts/install-testing-libs.sh <type> <path>` - Install testing packages by project type
86- `scripts/fix-tsconfig-spec.sh <path>` - Auto-fix moduleResolution settings
87
88## Key Principle
89
90**Generated code rarely matches monorepo patterns.** Post-generation fixes are MANDATORY. This skill ensures consistency and prevents pattern drift that causes mysterious failures.
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