TypeScript 6 Skill
Build and operate TypeScript 6+ projects with modern tsconfig patterns, compiler diagnostics, and release-note-grounded guidance.
| Status | Active |
| Version | 1.0.0 |
| Last Updated | 2026-04-12 |
| Confidence | 4/5 |
| Primary Source | https://www.typescriptlang.org/docs/handbook/release-notes/typescript-6-0.html |
What This Skill Does
Provides expert assistance for TypeScript 6+ development and configuration work. It focuses on the compiler changes and workflows that most often break or confuse real projects: explicit types, explicit rootDir, deprecated resolution/module settings, #/ imports, newer ES library typings surfaced in TS 6, and the TS 6→TS 7 bridge tools such as ignoreDeprecations and stableTypeOrdering. It also includes practical compiler-verification workflow and TS-safe type-pattern guidance that fit TypeScript 6+ projects without pretending older generic advice is TS 6-specific.
Core Capabilities
- Configure
tsconfig.jsonintentionally for TypeScript 6+ projects - Choose between
bundlerandnodenextmodule-resolution strategies without falling back to deprecatednode/node10 - Fix common regressions caused by
typesandrootDirchanges - Migrate deprecated
baseUrl, ES5-era targets, and legacy module settings to forward-looking replacements - Explain and apply TypeScript 6-era library typings and patterns such as
#/subpath imports,RegExp.escape,Temporal, andMap.getOrInsert - Use compiler diagnostics like
--showConfig,--explainFiles, and--traceResolutionbefore changing source code blindly - Apply TS-safe patterns such as
satisfies, exhaustive unions, and assertion functions when the codebase reveals type ambiguity - Use
--stableTypeOrderingand TS 7 preview context responsibly during migration work
Auto-Trigger Keywords
Primary Keywords
- typescript 6
- ts 6
- ignoreDeprecations
- stableTypeOrdering
- types array
- noUncheckedSideEffectImports
- moduleResolution node is deprecated
- baseUrl is deprecated
- tsc --showConfig
- tsc --traceResolution
- tsc --explainFiles
Secondary Keywords
- subpath imports
- #/ imports
- RegExp.escape
- Temporal API
- getOrInsert
- baseUrl migration
- downlevelIteration
- es2025
Error-Based Keywords
- "Cannot find name 'process'"
- "Cannot find name 'describe'"
- "moduleResolution node is deprecated"
- "output is going to dist/src"
- "baseUrl is deprecated"
- "stableTypeOrdering"
Known Issues Prevention
| Issue | Root Cause | Solution |
|---|---|---|
| Node or test globals disappear | The project relied on ambient type discovery that is no longer safe to assume during TS 6 migration work | Add explicit types entries |
Emit path shifts into dist/src/... |
The project relied on inferred source-root behavior that TS 6 migration work often needs to replace with explicit config | Set rootDir explicitly |
| TS 6 upgrade floods logs with warnings | Deprecated options survived from older configs | Replace them or temporarily gate them with ignoreDeprecations: "6.0" |
| Aliases do not work across environments | Bundler-only and Node-native alias strategies got mixed together | Pick paths, imports, and module resolution consistently |
| New ES APIs compile but break in runtime | Type-level support was mistaken for runtime support | Verify the runtime separately |
When to Use
Use This Skill For
- Building or maintaining a TypeScript 6+ codebase
- Fixing
tsconfig.jsonin an active TypeScript 6+ project - Choosing modern module resolution for bundlers or Node.js
- Migrating deprecated options such as
baseUrlandmoduleResolution: "node" - Adopting TS 6-era standard-library types and platform APIs
Don't Use This Skill For
- Generic TypeScript language tutoring unrelated to TS 6 changes
- Framework-specific runtime behavior that belongs to Next.js, Vite, Tauri, etc.
- TypeScript compiler API migration work for TS 7-native internals beyond high-level context
Version Policy
[!NOTE] This skill targets TypeScript 6+ with special attention to the TypeScript 6.0 default/deprecation changes. It includes TS 7 context only as comparison guidance, not as the primary implementation target. When exact feature timing or runtime availability matters, verify it against the official release notes and TSConfig docs.
Quick Usage
# Check the current project with an explicit TS 6 compiler
npx tsc --noEmit
# Compare type ordering behavior for TS 6 vs TS 7 migration work
npx tsc --noEmit --stableTypeOrdering
# Temporary migration shield while you remove deprecated options
# (do not keep this forever)
# "ignoreDeprecations": "6.0"Token Efficiency
| Approach | Estimated Tokens | Time |
|---|---|---|
| Manual TS 6+ docs diffing | ~12,000 | 60-90 min |
| With This Skill | ~6,000 | 20-30 min |
| Savings | 50% | ~40 min |
Reference Documentation
For deeper guidance on the most failure-prone areas, see:
| Topic | Reference File | Purpose |
|---|---|---|
| TS 6 Migration | migration-v6-reference.md |
Handle the highest-impact changes when moving into TS 6 |
| Defaults & Configuration | defaults-migration-reference.md |
Fix types, rootDir, and other TS 6+ configuration behavior |
| Deprecations | deprecations-reference.md |
Replace deprecated TS 6 options with durable alternatives |
| Module Resolution & Imports | module-resolution-imports-reference.md |
Choose bundler vs nodenext, and use #/ imports correctly |
| Standard Library Types | stdlib-types-reference.md |
Use es2025, Temporal, RegExp.escape, and upsert methods responsibly |
| Workflow & Diagnostics | workflow-diagnostics-reference.md |
Use compiler commands to verify config, file inclusion, and module resolution |
| Type Patterns | type-patterns-reference.md |
Apply satisfies, exhaustive unions, assertions, and typed results in TS 6+ code |
| TS 6→7 Migration Context | stable-ordering-ts7-reference.md |
Apply stableTypeOrdering, preview TS 7 differences, and avoid false assumptions |
See the References Index for navigation.
File Structure
typescript-v6/
├── SKILL.md # Quick-start patterns, critical rules, and upgrade guidance
├── README.md # This file - discovery and quick reference
└── references/
├── README.md # Reference index
├── migration-v6-reference.md # Dedicated TypeScript 6 migration guide
├── defaults-migration-reference.md # TS 6+ defaults and configuration behavior
├── deprecations-reference.md # Deprecated options and replacements
├── module-resolution-imports-reference.md # bundler/nodenext and `#/` imports
├── stdlib-types-reference.md # New platform/library types in TS 6
├── workflow-diagnostics-reference.md # Compiler commands for migration debugging
├── type-patterns-reference.md # TS-safe patterns for TS 6+ code
└── stable-ordering-ts7-reference.md # `stableTypeOrdering` and TS 7 contextDependencies
| Package | Version | Verified |
|---|---|---|
typescript |
^6 | 2026-04-12 |
node |
>=20 recommended for modern TS 6 + native subpath-import workflows | 2026-04-12 |
Official Documentation
- TypeScript 6.0 Release Notes
- TypeScript Docs
- TSConfig Reference
- Compiler Options Reference
- Choosing Compiler Options
Related Skills
vite-v8- Useful when TypeScript 6 config changes live inside a Vite 8 projectvitest-v4- Useful when TS 6 upgrades affect test globals, coverage config, orvitest.config.tsgithub-actions- CI workflow updates whentsc --noEmitor migration checks run in GitHub Actions
License: MIT