This document outlines our focused tasks for TypeScript 3.6, 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.

Note that this release shifts TypeScript from a 2-month release cycle to a 3-month release cycle.

Dates

• 3.5 ships (May 29th)
• TypeScript 3.6 Beta
  • Snap on July 12th
    • Kick off build for CTI
  • Release on July 16th
• First VS Code Insiders Build: August 1st?
• TypeScript 3.6 RC
  • Snap on August 9th
    • Kick off build for CTI
    • Kick off insiders for VS Code
  • Release on August 13th
• TypeScript 3.6 Final
  • Snap on August 23rd
    • Kick off build for CTI
    • Kick off insiders for VS Code
  • Release on August 27th 🚀

Work Items

Expected Work Items

• Bugs bugs bugs
• Language
  • Strongly typed iterators and generators
  • Stricter types for IteratorResult
  • ECMAScript private instance fields
• Compiler
  • APIs for --incremental builds and project references
  • More accurate array spread
  • UX on Promises
  • Investigate TypeScript plugin APIs
  • --declaration and --allowJs
• Infrastructure
  • Automated testing infrastructure for language service on real world code and DefinitelyTyped
  • Test tiering - faster local tests, longer CI runs
  • Release process overhaul
    • Need to enable automated cherry-picking.
    • Enable experimental feature branching
    • Must document the process here.
    • typescript-bot commenting that PRs don't have associated issues with a milestone
  • Migrate repo to ESLint
• Editor Features
  • Await feedback for more completion priority improvements
  • Automatic Semicolon Deletion for auto-imports/refactors
  • Auto-completion on Promises
  • Call hierarchy
  • TSServer diagnostics command

Deferred Work Items

None from planning meeting

Planning Meeting Notes

Motivations

• Bug backlog
• Goals and current 6-month roadmap
• GitHub user feedback (👍s)
• Feedback from customer interviews, social media, past iteration plans
• Visual Studio and Visual Studio Code feedback, as well as new functionality demands
• Actionable PRs (need to make a call)

General (compiler/infrastructure/reliability)

• Bugs bugs bugs
  • We simply haven't caught up with these from 3.4/3.5.
  • Committed ✅
• Strongly typed iterators and generators
  • PR out ✅
• Stricter types for IteratorResult
  • PR out. ✅
• ECMAScript private instance fields
  • PR out. ✅
• APIs for composite projects (--build mode)
  • PR out. ✅
• More accurate array spread.
  • PR out. ✅
• UX on Promises
  • High value for all users, useful to partner teams.
  • Committed ✅
• Investigate TypeScript plugin APIs 🏃
  • Ongoing.
• --declaration and --allowJs
  • Concerns with edge cases.
  • Can use the GitHub crawler to see how stable it is.
  • Do the work and let the crawler find the tail of bugs before we're ready to commit. ✅
• Testing infra
  • Automated testing infrastructure for language service on real world code and DefinitelyTyped
  • Test tiering - faster local tests, longer CI runs
  • Release process overhaul
    • Need to enable automated cherry-picking.
    • Enable experimental feature branching
    • Must document the process here.
    • typescript-bot commenting that PRs don't have associated issues with a milestone.
  • All of these, yes ✅
• Migrate repo to ESLint
  • ✅ Seems doable, @a-tarasyuk seems interested in helping!

Productivity

• Editor Features
  • Await feedback for more completion priority improvements
  • Automatic Semicolon Deletion for auto-imports/refactors
    • One of the most-demanded set of items
    • Committed ✅
  • Auto-completion on Promises
    • Seems useful for partner teams as well as JS users
    • Committed ✅
  • Call hierarchy
    • Ask from VS Code
    • Committed ✅
  • Diagnostics command
    • Seems like it would provide a low-cost high-value way for users to diagnose "TypeScript is slow in my editor."
    • Committed ✅