handbook: https://www.typescriptlang.org/docs/handbook/intro.html
4.3[2021.5.26]
- Separate Write Types on Properties
overrideand the--noImplicitOverrideFlag- Template String Type Improvements
- ECMAScript
#privateClass Elements ConstructorParametersWorks on Abstract Classes- Contextual Narrowing for Generics
- Always-Truthy Promise Checks
staticIndex Signatures.tsbuildinfoSize Improvements- Lazier Calculations in
--incrementaland--watchCompilations - Import Statement Completions
- Editor Support for
@linkTags - Go-to-Definition on Non-JavaScript File Paths
- Breaking Changes
- What’s Next?
4.2[2021.02.23]
- Smarter Type Alias Preservation
- Leading/Middle Rest Elements in Tuple Types
- Stricter Checks For The
inOperator --noPropertyAccessFromIndexSignatureabstractConstruct Signatures- The
--explainFilesFlag - Improved Uncalled Function Checks in Logical Expressions
- Destructured Variables Can Be Explicitly Marked as Unused
- Relaxed Rules Between Optional Properties and String Index Signatures
- Declare Missing Helper Function
- Breaking Changes