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TS-Pattern

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TS-Pattern — express TypeScript branching with patterns and exhaustiveness checks

OSS scale score 202.8OSS health 73Update pace 0 commits/30d
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Stars
15,167
Primary language
TypeScript
License
MIT
Repository last updated
Sep 11, 2026

Overview

TS-Pattern matches TypeScript unions, objects, arrays, tuples, and primitive values through declarative patterns. Cases are added with `.with()`, and `.exhaustive()` can detect missing branches at compile time.

Features and best fit

Based on official documentation; not hands-on tested · Content checked:

Match directly on object and union shapes

Patterns can describe nested objects, tuples, and primitive values while handlers receive appropriately narrowed input types.

Sources: [2]

Use `.exhaustive()` to catch missing cases during type checking

Discriminated unions can be checked so every variant is handled, including when new variants are added later.

Sources: [2][3]

For complex state-machine and union branching

It fits reducers, API-result handling, and domain models where nested switch or if/else logic becomes difficult to maintain.

Sources: [2]

Measure compile-time cost of advanced type inference

Runtime output is small, but pattern inference is handled by TypeScript. Large numbers of complex patterns may justify monitoring type-check performance.

Sources: [2][3]

Official sources

  1. [1]gvergnaud/ts-pattern repository(2026-09-21)
  2. [2]TS-Pattern README(2026-09-21)
  3. [3]ts-pattern package(2026-09-21)
  4. [4]TS-Pattern MIT license(2026-09-21)
Supplemental curator note

The current package is 5.9.0. TS-Pattern is more than switch syntax: it matches nested objects, tuples, and unions while using TypeScript narrowing and exhaustiveness checks. Because it relies on advanced type-level computation, very large pattern-heavy codebases should also monitor type-check performance.

Try it in 3 steps

  1. 1

    Install TS-Pattern

    Add the package using the npm command from the README.

    npm install ts-pattern
  2. 2

    Match a discriminated union

    Express union branches as structural patterns.

    match(result).with({ type: 'error' }, handleError).with({ type: 'ok' }, handleOk)
  3. 3

    Enable exhaustiveness checking

    Verify that TypeScript reports any unhandled union case.

    .exhaustive()
Check the official README

Growth

Growth trends · Last 30 days

15,167 Stars

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Development activity

Last 90 days · weekly

Commits (last 30 days)
0
Open PRs
24

Development activity is still being collected.

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GitHub data

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GitHub Topics

  • pattern-matching
  • typescript
  • ts
  • pattern
  • matching
  • inference
  • type-inference
  • exhaustive
  • conditions
  • branching
  • javascript
Stars
15,167
Forks
172
Watchers
31
Open issues
53
Contributors
26
Primary language
TypeScript
License
MIT
Repository last updated
Sep 11, 2026
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