BiteSizedChunks.comLearn one small thing at a time.

Course contentsShow

944The Bottom Type Concept
945Functions That Never Return
946never vs void Distinction
947Empty Union Resolution
948Assignability Rules for never
949never in Intersection Types
950Array and Object with never
951Generic Constraints and never
952Control Flow and Unreachable Code
953never as a Signal in Type Logic
954What Is an Exhaustive Check?
955The Basic Exhaustive Check Pattern
956Creating an assertNever Helper
957Exhaustiveness in Switch Statements
958Exhaustiveness in If-Else Chains
959Exhaustiveness with Discriminated Unions
960Compiler Errors When Adding New Union Members
961Exhaustiveness Without Runtime Code
962Exhaustiveness in Pattern Matching Libraries
963When to Skip Exhaustiveness Checks
964Functions That Never Return
965Typing throw Functions
966never in Control Flow Analysis
967Assertion Helper Functions
968Process Exit and Terminal Functions
969Unreachable Code After never
970never as the Empty Type in Conditionals
971Filtering Union Members with never
972Building Exclude with never
973Building Extract with never
974Building NonNullable with never
975never in Mapped Type Filters
976Conditional never for Key Remapping
977never vs undefined in Conditionals
978Distribution and never Propagation
979Practical Filtering Patterns with never

944The Bottom Type Concept
945Functions That Never Return
946never vs void Distinction
947Empty Union Resolution
948Assignability Rules for never
949never in Intersection Types
950Array and Object with never
951Generic Constraints and never
952Control Flow and Unreachable Code
953never as a Signal in Type Logic
954What Is an Exhaustive Check?
955The Basic Exhaustive Check Pattern
956Creating an assertNever Helper
957Exhaustiveness in Switch Statements
958Exhaustiveness in If-Else Chains
959Exhaustiveness with Discriminated Unions
960Compiler Errors When Adding New Union Members
961Exhaustiveness Without Runtime Code
962Exhaustiveness in Pattern Matching Libraries
963When to Skip Exhaustiveness Checks
964Functions That Never Return
965Typing throw Functions
966never in Control Flow Analysis
967Assertion Helper Functions
968Process Exit and Terminal Functions
969Unreachable Code After never
970never as the Empty Type in Conditionals
971Filtering Union Members with never
972Building Exclude with never
973Building Extract with never
974Building NonNullable with never
975never in Mapped Type Filters
976Conditional never for Key Remapping
977never vs undefined in Conditionals
978Distribution and never Propagation
979Practical Filtering Patterns with never

Lesson 952 of 1,796·22. The never TypePro lesson

Control Flow and Unreachable Code

How TypeScript uses never to mark code paths that can never execute after narrowing.

This lesson is for subscribers

You've completed the free preview. Subscribe to unlock every lesson in every course.

See pricing Back to course