Step 3 / Select topic TypeScript Types Hard

What this bank covers

• Distributive conditional type over a union
• Blocking distribution with tuple wrapping
• Distributing over never
• Conditional types applied to any
• infer with a variadic tuple pattern
• Multiple infer candidates in covariant positions
• Returning a deferred conditional type
• A reliable never check
• Inferring a parameter list tuple
• Assignability between distributive and non-distributive results
• Multiple inference candidates in covariant positions
• UnionToIntersection with disjoint literals
• Constrained infer that fails its constraint
• Template literal inference is non-greedy at the front
• Inferring return types and the never fallback
• Inferring from an overloaded function type
• Multiple covariant infer candidates
• infer with a failing constraint
• Contravariant infer candidates intersect
• Filtering keys with `as ... never`
• Homomorphic vs non-homomorphic mapping
• Template literal key remapping
• Stripping `readonly` with `-readonly`
• Homomorphic mapped types distribute over unions
• Omit-style key removal
• Optionality survives a homomorphic copy
• Stripping readonly with a mapped type modifier
• Non-homomorphic mapped types drop modifiers
• Template literal inference is left-to-right and non-greedy
• Intrinsic string types inside template literal types
• Constrained inference in template literal patterns
• Recursive template literal splitting
• Template literal key remapping in mapped types
• Distribution over a template literal pattern test
• Template literal types distribute, so `never` absorbs
• Assigning string literals to a template literal type
• Recursive trimming with template literal patterns
• Recursive template literal inference with Capitalize
• Tuple wrapping disables distribution
• boolean distributes as false | true
• Distribution powers Exclude
• Distribution needs a naked type parameter
• infer inside a distributed conditional
• Comparing a member against the saved union
• Distribution correlates the two tuple slots
• Only type parameters distribute
• Blocked distribution can collapse to never
• Distributing keyof over a union
• readonly arrays are a one-way street
• readonly property modifiers and assignability
• keyof reverses the subtype direction
• return-type void swallows any return type
• parameter counts in function assignability
• method bivariance makes Box covariant
• top and bottom types in the assignability lattice
• freshness adds excess property checking on top of assignability
• structural subtyping is directional
• index signatures are not interchangeable with declared properties
• Overload resolution order
• Overloads do not distribute over unions
• Arity and optional parameters in overload picking
• satisfies still runs full assignability checks
• satisfies supplies a contextual type
• satisfies keeps the inferred type
• Assigning to an overloaded call-signature type
• satisfies does not preserve literals by itself
• satisfies checks return types
• The implementation signature is not callable
• keyof over a discriminated union
• Extract with a union of discriminant values
• Assigning object literals to a discriminated union
• Non-distributive conditional over a union
• Filtering union members by the presence of a property
• Exhaustiveness checking with never
• Boolean literal types as discriminants
• A non-literal discriminant blocks narrowing
• Union to member assignability
• Narrowing a union with the in operator
• Multiple infer candidates in contravariant positions
• The `-?` modifier removes `undefined`, not `null`
• Indexed access through an array constraint
• Constraint checking on call arguments
• keyof constraint with indexed access return
• Multiple inference candidates under a primitive constraint
• Constraints referring to another type parameter
• Structural constraint satisfied by string and tuple
• Constraints and literal widening
• One type parameter, two inference sites
• Which type arguments satisfy a constraint
• Generic defaults versus constraints
• Recursive element-type flattening
• Recursive tuple-to-template-literal join
• Counting with a recursive accumulator tuple
• Self-referencing type aliases
• A recursive JSON union type
• Key remapping plus indexed access
• Recursive dotted path union as a constraint
• Recursive tuple reversal with indexed access
• Recursive deep lookup by string path
• Inferring the last tuple element