This page outlines specific features and fixes that are scheduled or planned for given releases. The current 6-month roadmap that outlines focus areas of work can be viewed here.
- Feature already available in
typescript@next
- Variadic types
- Investigate nominal typing support
- Flattening declarations
- Implement ES Decorator proposal
- Implement ES Private Fields
- Investigate Ambient, Deprecated, and Conditional decorators
- Investigate partial type argument inference
- Quick fix to Scaffold local
@typespackages - Investigate error messages in haiku or iambic pentameter
- Decorators for function expressions/arrow functions
See the 3.5 Iteration Plan for more details.
- Negated types
- The
Omithelper type -
--allowUmdGlobalAccessto use UMD globals from modules -
globalThisexpressivity fixes - Strongly typed iterators and generators
- Stricter types for
IteratorResult -
--declarationand--allowJs -
--declarationand--isolatedModules - APIs for composite projects (
--buildmode) - Smart Select API
- Sorted/prioritized completions
- Refactoring to extract type
See the 3.4 Iteration Plan for more details.
- Higher order function type inference
-
--incrementalbuilds with.tsbuildinfofiles - Improved support for read-only arrays and tuples
- Const contexts for literal expressions
-
globalThis - Refactorings to...
- Relaxed rules on methods of union types
- File-incremental builds in
--build --watchmode for composite projects
- Strict bind, call, and apply methods on functions
- Allow non-unit types in union discriminants
- Generic spread expressions in object literals
- Generic object rest variables and parameters
- Type-checking support for
BigInt - Configuration inheritance through node packages
- Supporting
Object.definePropertyproperty assignments in JS - Support printing the implied configuration object to the console with
--showConfig - Improved formatting and indentation for lists and chained calls
- Quick fixes to...
- Mapped tuple and array types
- Property assignments on function declarations
-
typesVersionsredirects - Error UX improvements
- Refactorings to...
- Support for project references/composite projects
- Tuples in rest parameters and spread expressions
- New
unknowntop type -
/// <reference lib="..." />reference directives - Support for
defaultPropsandpropTypesin React JSX elements - Error UX improvements
- Refactors to...
- Quick fixes to...
- Outlining spans for JSX expressions
- Auto-closing JSX tags
- Support number and symbol named properties with keyof and mapped types
- Support for passing generics to JSX elements
- Support for passing generics to tagged template calls
- Allow
import(...)-ing types at any location -
--prettyerror output by default - Support for
import.meta - New
--resolveJsonModule - Declaration source maps and code navigation via them
- Show suggestion diagnostics for open files
- Show unused declarations as suggestions
- Support setting quote style in quick fixes and refactorings
- New Rename File command
- Refactors to...
- Quick fix to...
- Conditional types
- Type inference in conditional types
- Predefined conditional types in
lib.d.ts - Improved control over mapped type modifiers
- Improved
keyofwith intersection types - New
--emitDeclarationOnly - Better handling for namespace-patterns in .js files
- Support for per-file JSX pragmas
- New Organize imports command
- Quick fix for uninitialized class properties
- Support for properties named with
const-declared symbols - Strict property initialization checks in classes
- Definite assignment assertions
- Improved type inference for object literals
- Improved handling of structurally identical classes
- Fixed length tuples
- Type guards inferred from
inoperator - Numeric separators
- Support for
import d from "cjs"form CommonJS modules with--esModuleInterop - Apply all quick fixes in a file
- Refactors to convert CommonJS module to ES6 module
- Support for incremental builder compiler API
- Quick fix to add missing
asynckeyword - Completion list preselects suggested item based on context
- Completion list includes
this., brackets, and curlies for JSX
- Strict function types
- Support for JSX Fragments
- Cached tagged template objects in modules
- Include localized diagnostics in npm
- Suppress errors in .ts files using
// @ts-ignorecomments - Speed improvements to
--watch - Automatic imports from completion lists
- Refactors to...
- Quick fixes to...
- Support outlining for
// #regions
- Assertion/cast JSDoc syntax in
checkJsmode - Refactoring to extract functions & methods
- Optional
catchbinding - Quick fixes to...
- Infer from generic function return types
- Contextual generic function types
- Stricter generic signature checks
- Covariant checking for callback parameters
- String valued members in enums
- Weak type detection
- ES dynamic
import()expressions - Refactoring support in Language Service API
- Suggestions and quick fixes for spelling corrections in error messages
- Generator support for ES3/ES5
- Asynchronous iterators
- Generic defaults
- Controlling
thisin methods of object literals through contextual type - JSX stateless components overload resolution
- JSX
childrenchecking - New
--strictmaster option - Report errors in .js files with new
--checkJs - Enhanced
tsc --initoutput - Language Service Extensibility
- Mixin classes
- Allow deriving from object and intersection types
- Support for
new.target - Improved checking of nullable operands in expressions
- Update
__extendsto useObject.setPrototypeOf - Allow property (dotted) access for types with string index signatures
- Support for JSX spread children
- New
--jsx react-native - Support for the
objecttype. - More Quick Fixes!
- Switch to a transformation-based emitter
-
async/awaitsupport for ES5/ES3 - Support for external helpers library
- Static types for dynamically named properties (
keyof TandT[K]) - Mapped types (e.g.
{ [P in K]: T[P] }) - Support ESNext object property spread and rest
- Better inference for literal types
- Use returned values from super calls as 'this'
- Control flow analysis for implicit any variables
- Control flow analysis for array construction
- Narrow string and number types in literal equality checks
- Contextual typing of partially annotated signatures
- Normalize union/intersection type combinations
- New
--jsxFactory - New
--alwaysStrict - Support for
--target ES2016,--target ES2017and--target ESNext - Configuration inheritance
- Go to implementation support
- Completions in imports and triple-slash reference paths
- Quick fixes support in language service API
- Untyped (implicit-any) imports
- Non-nullable types
- Control flow based type analysis
- Discriminated union types
- Improved definition file acquisition
- Specifying
thistypes for functions - Type guards on property access
- Readonly properties and index signatures
- Use path mappings in module resolution
- Shorthand ambient module declarations and wildcard matching in module names
- Implicit index signatures
- Support private and protected constructors
- Support
abstractproperties - Optional properties in classes
- The
nevertype -
--skipLibCheckcompiler option - Support for declaration output folder using
--declarationDir - Glob support in tsconfig.json
- Improve lib.d.ts modularity and new
--libsupport - Support for UMD module definitions
- Trailing Commas in Function Param Lists
- Support for jsdoc
@typedeffor JS files - Completion lists for string literals
- Module name in imports allow .js extension
- Support 'target:es5' with 'module:es6'
- Flag unused declarations with
--noUnusedLocalsand--noUnusedParameters - Number, boolean, and Enum literal types
- Allow JavaScript in TypeScript compilations with
--allowjs - Allow captured
let/constin loops - Flag unreachable code
- Concatenate module output with
--outFile - Accept comments in tsconfig.json
- Stylize error messages in terminal output with
--pretty - Support for
--outFilewith named pipes, sockets, and special devices - Support computed property with literal names
- String literal types
- Stateless Functional Components in JSX
- Improved union/intersection type inference
- Support for F-Bounded Polymorphism
- Support full path for
-project/-pparameter - Extract type information from JSDoc in js files
- Support for
defaultimport interop with SystemJS using--allowSyntheticDefaultImports - Recognize prototype assignments in JavaScript files
- Augmenting global/module scope from other modules
- Use tsconfig.json as higher priority source of configuration in Visual Studio
-
this-based type guards - Support for custom JSX factories using
--reactNamespace - Improved checking of for-in statements
- Colorization of JSX code in VS 2015
- Publish official TypeScript NuGet packages
- ES7 exponentiation operator
- Polymorphic
thistype - Support
--modulewith--target es6 - Support for decorators when targeting ES3
-
async/awaitsupport for ES6 (Node v4) - Improved checking of destructuring with literal initializers
- ES6 Generators
- Local types
- Generic type aliases
- Expressions in class extends clauses
- Class expressions
-
excludeproperty in tsconfig.json - User defined type guard functions
- External module resolution enhancements
- JSX support
- Intersection types
-
abstractclasses and methods - Strict object literal assignment checking
- Declaration merging for classes and interfaces
- New --init
- Support for Destructuring
- Support for Spread Operator
- Support for ES6 Modules
- Support for for..of
- Support for ES6 Unicode specification
- Support for Symbols
- Support for Computed properties
- Support for tsconfig.json files
- Support for let and const in ES3/ES5
- Support for tagged templates in ES3/ES5
- Expose a new editor interface through TS Server
- Support for ES7 Decorators proposal
- Support for Decorator type metadata
- New --rootDir
- New ts.transpile API
- Support --module umd
- Support --module system
- New --noEmitHelpers
- New --inlineSourceMap
- New --inlineSources
- New --newLine
- New --isolatedModules
- Support for new
namespacekeyword - Support for tsconfig.json in Visual Studio 2015
- Improved template literal highlighting in Visual Studio 2013
- Support for Union Types and Type Guards
- New --noEmitOnError
- New --target ES6
- Support for Let and Const
- Support for Template Literals
- Library typings for ES6
- Support for Const enums
- Export Language Service public API
- Language service re-write to target new compiler
- Support for protected members in classes
- Support for Tuple Types