TypeScript 3.7 Iteration Plan

[DanielRosenwasser]

This document outlines our focused tasks for TypeScript 3.7, 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.

Dates

Date	Event
August 28th	TypeScript 3.6 Release
September 27th	Create 3.7 Beta (3.7.0) Build for Testing
October 1st	TypeScript 3.7 Beta Release
October 18th	Create 3.7 RC (3.7.1) Build for Testing
October 22nd	TypeScript 3.7 RC Release
November 1st	Create 3.7 Final (3.7.2) Build for Testing
November 5th	TypeScript 3.7 Final Release 🚀

Work Items

Expected Work Items

• Language
  • Optional Chaining
  • Nullish Coalescing
  • Assertion Signatures
  • Recursive Type References
  • ECMAScript Private Fields
  • Top-Level await
  • Compiler
  • --declaration and --allowJs
  • --declaration and --isolatedModules
• Editor Features
  • Call hierarchy
  • Polishing auto-import functionality (fixing issues, adding functionality)
  • Project references improvements
    • Opening unbuilt project reference solutions (for fresh git clone scenarios)
    • Delayed loading of projects (improving performance and memory consumption)
• Performance
  • Rolling Issues
  • Experiments in Perf
  • Customer Development/Investigation
  • Get performance data from TSServer crawler work.
• Infrastructure
  • Automated testing infrastructure for the language service on real world code
  • Migrate repo to ESLint
  • Investigate smaller package publish
  • Dual-publishing @types on GitHub package registry
• Website and Documentation
  • New Handbook
  • Redesign

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)

• Language

  • Type System Innovation
    • Assertion Signatures
    • Recursive Type References
  • Standards Conformance
    • ECMAScript Private Fields
    • Nullish Coalescing
    • Optional Chaining
    • Top level await
    • Transition plan for class fields

• Compiler

  • --declaration and --allowJs
  • --declaration and --isolatedModules
  • Investigate compiler plugin API

• Infrastructure

  • Migrate repo to ESLint
  • Investigate smaller package publish
    • Might have ideas for removing unnecessary files.
  • Dual-publishing @types on GitHub package registry
    • Today, types packages are automatically fetched to power IntelliSense in VS and VS Code.
    • GitHub now provides its own registry.
    • We want to ensure that there is some level of redundancy.

• Editor Productivity

  • Call hierarchy
  • Polishing auto-import functionality (fixing issues, adding functionality)
    • Just expect more to come in.
  • Project references improvements
    • Opening unbuilt project reference solutions (git clone scenarios)
    • Delayed loading of projects (improving performance and memory consumption)

• Website and Documentation

  • New Handbook
    • Finishing up chapters (Enums and Modules) in core handbook
  • Redesign
    • Core messaging
    • Samples
    • New community page for meetups/conferences
    • Integrating the new handbook into the site
    • Ensure full accessibility

• Stability

  • TSServer crawler
    • Currently takes a fixed set of repos
      • That's fine.

• Performance

  • Rolling Issues
  • Experiments in Perf
    • Can we incrementally bind, reuse checking results, etc.?
  • Customer Development/Investigation
    • Establish hypotheses
    • Validate/invalidate
    • Concept/value testing
    • Implementation
  • Get performance data from TSServer crawler work.

[AnyhowStep]

Nullish Coalescing

Links to "Top Level Await" issue

[ahejlsberg]

@DanielRosenwasser Fixed link to Nullish Coalescing and added Recursive Type References.

[DanielRosenwasser]

Thanks @AnyhowStep and @ahejlsberg. Additionally, I've made a change to the schedule. We will be reducing the feature period given that there's a convenient opportunity to align with Visual Studio, and we feel like the planned features are all individually in a good place.

[j-oliveras]

Someone should move --declaration and --isolatedModules on roadmap to version 3.7 (currently on 3.6).