This page outlines specific features and fixes that are scheduled or planned for given releases. The 6-month roadmaps that outlines focus areas of work can be viewed for

• January to June 2021 (current)
• January to December 2020
• July to December 2019
• January to June 2019

• Feature already available in typescript@next

• Investigate nominal typing support
• Flattening declarations
• Implement ES Decorator proposal
• Investigate Ambient, Deprecated, and Conditional decorators
• Investigate partial type argument inference
• Quick fix to Scaffold local @types packages
• Investigate error messages in haiku or iambic pentameter
• Decorators for function expressions/arrow functions

See the 5.0 Iteration Plan for more details.

• Standard ECMAScript Decorators
• const Type Parameters
• --moduleResolution bundler
• extends Support for Multiple tsconfig.json Files
• Declaration Files for non-JavaScript Files with --allowArbitraryExtensions
• export type *
• --verbatimModuleSyntax
• @satisfies JSDoc Tag in JavaScript
• @overload JSDoc Tag in JavaScript
• Unification Between Numeric and Literal enums
• Toggling Certain Compiler-Specific Flags Under --build
• Flag Deprecations
• Improved in Checks Under --noUncheckedIndexedAccess
• Editor Support for Case-Sensitive Import Sorting
• Editor Support for Exhaustive switch/case Snippet Completions
• Virtual File System Support for TSServer
• Optimizations
  • Migrate to Modules
  • Node Monomorphization
  • Symbol Monomorphization
  • Identifier Size Reduction
  • Printer Caching
  • Limited TDZ Avoidance

See the 4.9 Iteration Plan for more details.

• Narrowing Checks for Unknown Properties with the in Operator
• satisfies operator
• Auto-accessors in classes
• Forbidden Equality Checks Against NaN
• File Watching Defaults Using to File-System Events
• "Remove Imports" Command for Editors
• Go-to-Definition on return Keywords
• Optimizations
  • forEachChild as a Jump Table
  • visitEachChild as a Jump Table
  • Lazily Intersect and Normalize Substitution Type Constraints

See the 4.8 Iteration Plan for more details.

• Improved Narrowing on Generics and Intersection Reduction
• Improved Inference for infer Types in Template String Types
• --build, --watch, and --incremental Performance Improvements
• Errors When Comparing Object and Array Literals
• Improved Inference from Binding Patterns
• Resilient File-Watching During Large File Changes
• Find-All-References Performance Improvements

See the 4.7 Iteration Plan for more details.

• --module and --moduleResolution options node16 and nodenext
• Control Flow and Class Initialization Checks for Computed Properties
• Instantiation Expressions
• Improved Inference Between Function-Initialized Properties and Methods
• extends Constraints on infer Type Variables
• Optional Variance Annotations
• moduleSuffixes Option For Resolution
• resolution-mode for /// <reference types="..." /> Directives
• resolution-mode for import type
• Allow typeof on #private Fields
• Object Method Snippet Completions
• Grouping-Aware Organize Imports
• Go to Source Definition/JavaScript Implementation

See the 4.6 Iteration Plan for more details.

• Narrowing for Variables Destructured from Discriminated Unions
• Relaxed Checks on Code Before super()
• Improved Recursion Depth Checks
• Indexed Access Inference Improvements
• --target es2022
• Syntax and Binding Errors in JavaScript Files
• Release of @typescript/analyze-trace

See the 4.5 Iteration Plan for more details.

• lib Overrides from node_modules
• Awaited and Promise Function Improvements
• Tail Recursive Evaluation of Conditional Types
• Template String Discriminants
• --module es2022
• Controls for Import Elision via --preserveValueImports
• type Modifiers on Import Names
• in Checks on #private Fields
• Import Assertions
• Speed Improvements on Windows/Mac via realpathSync.native
• Snippet Completions for Subclass Methods
• Snippet Completions for JSX Attributes
• Better Editor Support for Unresolved Types

See the 4.4 Iteration Plan for more details.

• Control Flow Analysis of Aliased Conditions
• Generalized index signatures
• Strict optional property checks with --strictOptionalProperties
• Use unknown for try/