TypeScript 4.0 Iteration Plan

[DanielRosenwasser]

This document outlines our focused tasks for TypeScript 4.0, as well as some of the discussion that explains how/why we prioritized certain work items. Nothing is set in stone, but we will strive to complete them in a reasonable timeframe.

Date	Event
May 12th	TypeScript 3.9 Release (past)
June 22nd	Create 4.0 Beta (4.0.0) Build for Testing
June 25th	TypeScript 4.0 Beta Release
July 31st	Create 4.0 RC (4.0.1) Build for Testing
August 6th	TypeScript 4.0 RC Release
August 14th	Create 4.0 Final (4.0.2) Build for Testing
August 20th	TypeScript 4.0 Final Release 🚀

Language Features

• Short-Circuiting Assignment Operators
• Labeled Tuple Elements
• Class Property Inference from Constructors
• Forward Declarations
• Investigate the awaited Type
• JSX Factory Updates
• unknown on catch Clause Bindings
• Variadic Tuples

Editor Productivity

• Refactorings
  • Convert to Optional Chaining and Coalescing
• Discoverability in Refactoring (ideas)
• Lightweight Navigation
• Improved Auto-Import
• Editor support for /** @deprecated */ tags
• Editor support for /** @see */ tags
• Semantic Highlighting

Performance

• More Type-Checking Optimizations
• Investigate Bottlenecks in Larger Apps

Infrastructure

• Migrate TypeScript to Modules
• Expand Commands Tested in TSServer Crawler
• GitHub Crawler Infrastructure to Find Breaking Changes

Investigate High-Demand Bug Fixes

• Don't Widen Computed Property Keys
• Cleaning Files Under --watch
• Higher Order Component Issues
• Remove --declaration Emit Error
• Inference for Proxies
• change events on <input type="file">have no files field
• Poor Error for isolatedModules

[DanielRosenwasser]

@typescript-bot bump release-4.0

[typescript-bot]

Heya @DanielRosenwasser, I've started to update the version number on release-4.0 to 4.0.2 for you. Here's the link to my best guess at the log.

[Aravin]

it's Aug 20 :)

[DanielRosenwasser]

Heh, it's still August 19th here, and even 20 minutes from now I think you'll have to wait a bit more. We have nightly releases on npm if you can't take another minute! 😄

[Ayfri]

Waiting for the release, already out in npm :)

[DanielRosenwasser]

@typescript-bot bump release-4.0

[typescript-bot]

Heya @DanielRosenwasser, I've started to update the version number on release-4.0 to 4.0.3 for you. Here's the link to my best guess at the log.

[DanielRosenwasser]

@typescript-bot bump release-4.1

[typescript-bot]

Heya @DanielRosenwasser, I've started to update the version number on release-4.1 to 4.1.1-rc for you. Here's the link to my best guess at the log.

[DanielRosenwasser]

Oh no

[DanielRosenwasser]

@typescript-bot bump release-4.0

[typescript-bot]

Heya @DanielRosenwasser, I've started to update the version number on release-4.0 to 4.0.4 for you. Here's the link to my best guess at the log.

[DanielRosenwasser]

@typescript-bot bump release-4.0

[typescript-bot]

Heya @DanielRosenwasser, I've started to update the version number on release-4.0 to 4.0.5 for you. Here's the link to my best guess at the log.

[DanielRosenwasser]

@typescript-bot bump release-4.0

[typescript-bot]

Heya @DanielRosenwasser, I've started to update the version number on release-4.0 to 4.0.8 for you. Here's the link to my best guess at the log.