TypeScript new features on each version

Jul 13, 2020

Announcing TypeScript 3.9 May 12th, 2020
- Improvements in Inference and Promise.all
- Speed Improvements
- // @ts-expect-error Comments
- Uncalled Function Checks in Conditional Expressions
- Editor Improvements
- Breaking Changes
Announcing TypeScript 3.8 February 20th, 2020
- Type-Only Imports and Exports
- ECMAScript Private Fields
- export * as ns Syntax
- Top-Level await
- JSDoc Property Modifiers
- Better Directory Watching on Linux and watchOptions
- “Fast and Loose” Incremental Checking
- Editor Features
  - Convert to Template String
  - Call Hierarchy
- Breaking Changes
Announcing TypeScript 3.7 November 5th, 2019
- Optional Chaining
- Nullish Coalescing
- Assertion Functions
- Better Support for never-Returning Functions
- –declaration and –allowJs
- (More) Recursive Type Aliases
- The useDefineForClassFields Flag and The declare Property Modifier
- Build-Free Editing with Project References
- Uncalled Function Checks
- Flatter Error Reporting
- // @ts-nocheck in TypeScript Files
- Semicolon Formatter Option
- Website and Playground Updates
- Breaking Changes
Announcing TypeScript 3.6 August 28th, 2019
- Language and Compiler
- New TypeScript Playground
- Editor Features
  - Semicolon-Aware Code Edits
  - Smarter Auto-Imports
- Breaking Changes
- What’s Next?
Announcing TypeScript 3.5 May 29th, 2019
- Compiler and Language
- Editor Tooling
  - Smart Select
  - Extract to type alias
- Breaking changes
- What’s next
Announcing TypeScript 3.4 March 29th, 2019
- Faster subsequent builds with the –incremental flag
- Higher order type inference from generic functions
- Improvements for ReadonlyArray and readonly tuples
- const assertions
- Type-checking for globalThis
- Convert parameters to destructured object
- Breaking changes
Announcing TypeScript 3.3 January 31st, 2019
Announcing TypeScript 3.2 November 29th, 2018
- strictBindCallApply
- Object spread on generic types
- Object rest on generic types
- Node.js-based resolution for tsconfig.json inheritance
- Diagnosing tsconfig.json with –showConfig
- BigInt
- Object.defineProperty declarations in JavaScript
- Error message improvements
- Improved narrowing for tagged unions
- Editing improvements
- Breaking changes and deprecations
  - A note for NuGet and Visual Studio 2015 users
- What’s next
Announcing TypeScript 3.1 October 8th, 2018
- Mappable tuple and array types
- Easier properties on function declarations
- Version redirects for TypeScript via typesVersions
- Refactor from .then() to await
- Breaking changes
Announcing TypeScript 3.0 July 30th, 2018
- Project references
- Extracting and spreading parameter lists with tuples
- Richer tuple types
- The unknown type
- Improved errors and UX
  - Related error spans
  - Improved messages and elaboration
- Support for defaultProps in JSX
- /// directives
- Editor Productivity
- Breaking changes
Announcing TypeScript 2.9 May 31st, 2018
- Rename file and move declaration to new file
- Unused span reporting
- Convert property to getter/setter
- import() types
- –pretty by default
- Support for well-typed JSON imports
- Type arguments for tagged template strings
- Support for symbols and numeric literals in keyof and mapped object types
Announcing TypeScript 2.8 March 27th, 2018
- Conditional types
- Declaration-only emit
- @jsx pragma comments
- JSX now resolved within factory functions
- Granular control on mapped type modifiers
- Organize imports
- Fixing uninitialized properties
Announcing TypeScript 2.7 January 31st, 2018
Announcing TypeScript 2.6 October 31st, 2017
Announcing TypeScript 2.5 August 31st, 2017
Announcing TypeScript 2.4 June 27th, 2017
Announcing TypeScript 2.3 April 27th, 2017
Announcing TypeScript 2.2 February 22nd, 2017
Announcing TypeScript 2.1 December 7th, 2016
Announcing TypeScript 1.8 February 22nd, 2016
Announcing TypeScript 1.7 November 30th, 2015
Announcing TypeScript 1.6 September 16th, 2015
Announcing TypeScript 1.6 Beta: React/JSX, better error checking, and more September 2nd, 2015
Announcing TypeScript 1.5 July 20th, 2015
Announcing TypeScript 1.4 January 16th, 2015
Announcing TypeScript 1.3 November 12th, 2014
Announcing TypeScript 1.0.1 May 13th, 2014
Announcing TypeScript 1.0 April 2nd, 2014
Announcing TypeScript 0.9.5 December 5th, 2013
Announcing TypeScript 0.9.1.1 August 21st, 2013
Announcing TypeScript 0.9.0.1 June 28th, 2013
Announcing TypeScript 0.9 June 18th, 2013
Announcing TypeScript 0.8.3.1 April 1st, 2013
Announcing TypeScript 0.8.3 February 27th, 2013
Announcing TypeScript 0.8.2 January 21st, 2013
Announcing TypeScript 0.8.1.1 December 5th, 2012
Announcing TypeScript 0.8.1 November 15th, 2012