TypeScript — Complete Learning Roadmap

Phase 1: Foundations (Topics 1–5)

#	Topic	Key Concepts
01	Setup & Configuration	tsc, tsconfig.json, strict mode, target/module, watch mode
02	Primitive Types & Special Types	string, number, boolean, any, unknown, void, never, null, undefined, bigint, symbol
03	Arrays, Tuples & Enums	typed arrays, readonly arrays, tuples, labeled tuples, numeric/string/const enums
04	Type Inference & Annotations	implicit inference, contextual typing, const assertions, satisfies operator
05	Union & Intersection Types	union narrowing, literal types, intersection merging, distributive behavior

Phase 2: Functions & Objects (Topics 6–10)

#	Topic	Key Concepts
06	Functions & Overloads	parameter types, return types, optional/default params, rest params, overloads, this parameter
07	Objects & Interfaces	object types, optional properties, readonly, index signatures, extending interfaces, interface merging
08	Type Aliases vs Interfaces	when to use each, computed properties, mapped types, declaration merging, practical guidelines
09	Type Assertions & Narrowing	as keyword, non-null assertion, typeof guards, instanceof, in operator, custom type guards, assertion functions
10	Classes & Access Modifiers	public, private, protected, readonly, abstract classes, implements, static members, parameter properties

Phase 3: Generics & Advanced Types (Topics 11–15)

#	Topic	Key Concepts
11	Generics	generic functions, generic interfaces, generic classes, constraints (extends), default type params, multiple type params
12	Utility Types	Partial, Required, Readonly, Pick, Omit, Record, Exclude, Extract, NonNullable, ReturnType, Parameters, Awaited
13	Mapped Types & Template Literal Types	key remapping, modifier removal, template literal unions, intrinsic string types, recursive types
14	Conditional Types & infer	extends keyword, infer extraction, distributive conditionals, nested conditionals, type-level programming
15	Discriminated Unions & Exhaustive Checks	tagged unions, switch narrowing, never for exhaustiveness, pattern matching, state machines

Phase 4: Modules & Declarations (Topics 16–18)

#	Topic	Key Concepts
16	Modules & Namespaces	ESM import/export, re-exports, barrel files, dynamic import, namespaces, module augmentation
17	Declaration Files & Ambient Types	.d.ts files, declare keyword, @types packages, global augmentation, module declarations, triple-slash directives
18	Decorators	class decorators, method decorators, property decorators, parameter decorators, decorator factories, metadata

Phase 5: Real-World Patterns (Topics 19–20)

#	Topic	Key Concepts
19	Error Handling Patterns	Result/Either type, custom error classes, type-safe try/catch, error hierarchies, exhaustive error handling
20	Advanced Patterns	branded/opaque types, builder pattern, type-safe event emitter, phantom types, variance, recursive types, HKT simulation

Suggested Learning Path

Phase 1 (Foundations) ──▶ Phase 2 (Functions & Objects) ──▶ Phase 3 (Generics & Advanced)
                                                                       │
                                            Phase 4 (Modules) ◀───────┘
                                                    │
                                            Phase 5 (Patterns) ◀───────┘

Format: Each topic folder contains a README.md (concepts + notes) and a .ts code file (10–15+ commented examples).

01 — Setup & Configuration