TypeScript 5.8 Iteration Plan

[DanielRosenwasser]

This document outlines our focused tasks for TypeScript 5.8. It minimally indicates intent to investigate tasks or contribute to an implementation. Nothing is set in stone, but we will strive to complete these tasks in a reasonable timeframe.

Date	Event
2024-11-22	TypeScript 5.7 Release
2025-01-24	Create 5.8 Beta (5.8.0) Build for Testing
2025-01-28	TypeScript 5.8 Beta Release
2025-02-07	Create 5.8 RC (5.8.1) Build for Testing
2025-02-11	TypeScript 5.8 RC Release
2025-02-21	Create 5.8 Final (5.8.2) Build for Testing
2025-02-25	TypeScript 5.8 Final Release 🚀

gantt
    dateFormat  YYYY-MM-DD
    TypeScript 5.7 Stabilization Period : 2024-11-18, 2024-11-22
    TypeScript 5.8 Beta Development : 2024-11-18, 2025-01-24
    TypeScript 5.8 RC Development : 2025-01-25, 2025-02-07
    TypeScript 5.8 Stabilization Period : 2025-02-08, 2025-06-21
todayMarker stroke-width:5px,stroke:#0f0,opacity:0.5

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Compiler and Language

• Checked Return Statements for Conditional and Indexed Access Types
• --module node18 and --module node20
• --erasableSyntaxOnly Option
• Investigate Preserving Computed Properties with Entity Names for Declaration Emit
• Introduce --libReplacement
• lib.d.ts Updates

Editor and Language Service

• Iterate on Expandable Hovers

Performance

• Normalize Paths with Fewer Allocations
• Skip tsconfig.json Checks on Program Updates

Website and Docs

• Simplify and Refactor Website for Faster Builds

[RyanCavanaugh]

@typescript-bot create release-5.8

[typescript-bot]

Starting jobs; this comment will be updated as builds start and complete.

Command	Status	Results
create release-5.8	✅ Started	✅ Results

[typescript-bot]

Hey, @RyanCavanaugh! I've created release-5.8 with version 5.8.0-beta for you.

[DanielRosenwasser]

FWIW we'll probably go out with the beta tomorrow morning.

[DanielRosenwasser]

@typescript-bot sync release-5.8

[typescript-bot]

Starting jobs; this comment will be updated as builds start and complete.

Command	Status	Results
sync release-5.8	✅ Started	✅ Results

[typescript-bot]

Hey, @DanielRosenwasser! I've pulled main into release-5.8 for you.

[DanielRosenwasser]

@typescript-bot sync release-5.8

[typescript-bot]

Starting jobs; this comment will be updated as builds start and complete.

Command	Status	Results
sync release-5.8	✅ Started	✅ Results

[typescript-bot]

Hey, @DanielRosenwasser! I've pulled main into release-5.8 for you.

[DanielRosenwasser]

@typescript-bot bump release-5.8

[typescript-bot]

Starting jobs; this comment will be updated as builds start and complete.

Command	Status	Results
bump release-5.8	✅ Started	✅ Results