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TypeScript Developer Tutorials Roadmap

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Section 1: Foundations - Setting Up and Getting Started

• Understanding the Problem TypeScript Solves:
  • Challenges of large-scale JavaScript applications.
  • The benefits of static typing.
  • What is TypeScript? (A superset of JavaScript).
  • How TypeScript relates to JavaScript (compilation).
• Setting Up Your Development Environment:
  • Installing Node.js and npm/yarn/pnpm.
  • Installing TypeScript globally or locally (`npm install -g typescript`).
  • Choosing a code editor (VS Code is highly recommended with excellent TypeScript support).
  • Basic `tsconfig.json` setup:
    • `target`: The JavaScript version to compile to.
    • `module`: The module system to use (CommonJS, ESNext, etc.).
    • `outDir`: The output directory for compiled JavaScript files.
    • `rootDir`: The root directory of your TypeScript source files.
    • `strict`: Enabling strict type-checking options (highly recommended).
  • Compiling TypeScript: Using the `tsc` command.
  • Setting up a simple project with `tsc --init`.
• Basic Types:
  • `boolean`: True or false.
  • `number`: Integers and floating-point numbers.
  • `string`: Textual data.
  • `array`: Arrays of a specific type (`number[]`, `string[]`, `Array`).
  • `tuple`: Arrays with a fixed number of elements of known types.
  • `enum`: Named constants.
  • `any`: Opting out of type checking (use sparingly).
  • `void`: For functions that don't return a value.
  • `null` and `undefined`: Representing absence of a value.
  • `never`: For functions that never return (e.g., throwing an error).
  • `unknown`: A safer alternative to `any` (requires type checking before use).
• Type Annotations:
  • Explicitly specifying types for variables, function parameters, and return values.
  • Type inference: How TypeScript infers types automatically.
• Functions:
  • Typing function parameters and return values.
  • Optional and default parameters.
  • Rest parameters.
  • Function overloads.

Section 2: Working with Complex Types and Structures

• Interfaces:
  • Defining the shape of objects.
  • Optional and read-only properties.
  • Extending interfaces.
  • Implementing interfaces with classes.
• Type Aliases:
  • Creating custom names for types.
  • Union types (`|`): Allowing a variable to be one of several types.
  • Intersection types (`&`): Combining multiple types into one.
  • Literal types: Specifying exact values (`'hello'`, `123`, `true`).
  • Type aliases vs. Interfaces: Understanding the differences and when to use each.
• Classes:
  • Defining classes with properties and methods.
  • Access modifiers (`public`, `private`, `protected`).
  • Constructors.
  • Inheritance.
  • Abstract classes.
  • Implementing interfaces.
• Generics:
  • Writing reusable code that works with multiple types.
  • Generic functions.
  • Generic interfaces.
  • Generic classes.
  • Generic constraints.
• Type Assertions:
  • Telling the compiler about the type of a variable when it cannot infer it (`as type` or ``).
  • Understanding the risks of type assertions.
• Type Narrowing:
  • Using control flow analysis (if/else, switch, `typeof`, `instanceof`, `in`, equality checks) to determine a more specific type within a code block.
  • Discriminant Unions.

Section 3: Modules and Advanced Concepts

• Modules:
  • Understanding ES Modules (`import`/`export`) in TypeScript.
  • Importing and exporting types, interfaces, classes, and values.
  • Default and named exports.
  • Module resolution strategies.
• Declaration Files (`.d.ts`):
  • Understanding the purpose of declaration files (providing type information for existing JavaScript code).
  • Writing declaration files for libraries that don't have them.
  • Using `@types` from npm.
• Decorators (Experimental):
  • Understanding the concept of decorators (adding metadata or modifying classes/methods/properties).
  • Using decorators (requires enabling in `tsconfig.json`).
• Utility Types:
  • Exploring built-in utility types (e.g., `Partial`, `Required`, `ReadOnly`, `Pick`, `Omit`, `Exclude`, `Extract`).
• Conditional Types:
  • Defining types that depend on a condition (`T extends U ? X : Y`).
• Mapped Types:
  • Creating new types by transforming properties of existing types.
• Index Signatures:
  • Defining the type of properties when the property names are not known in advance (e.g., for objects used as dictionaries).

Section 4: Integration with Frameworks and Libraries

• Using TypeScript with React:
  • Typing function components.
  • Typing class components.
  • Typing props and state.
  • Typing hooks.
  • Typing event handlers.
• Using TypeScript with Vue.js:
  • Using TypeScript with the Options API (using `defineComponent`).
  • Using TypeScript with the Composition API (recommended).
  • Typing props, data, computed properties, and methods.
  • Typing Vuex store.
  • Typing Vue Router.
• Using TypeScript with Node.js/Express:
  • Setting up a Node.js project with TypeScript.
  • Typing Express request and response objects.
  • Typing database interactions.
• Integrating with other popular libraries:
  • Axios, Lodash, etc. (using `@types`).

Section 5: Tooling, Configuration, and Best Practices

• Advanced `tsconfig.json` Options:
  • `noImplicitAny`, `noImplicitThis`, `strictNullChecks`, `strictFunctionTypes`, `strictPropertyInitialization`.
  • `esModuleInterop`, `allowSyntheticDefaultImports`.
  • `paths` for module aliases.
  • Excluding files and directories.
• Linting and Formatting:
  • Using ESLint with TypeScript.
  • Using Prettier with TypeScript.
  • Integrating with VS Code extensions.
• Testing TypeScript Code:
  • Setting up testing frameworks (Jest, Mocha, Vitest) with TypeScript.
  • Writing tests for TypeScript code.
• Debugging TypeScript Code:
  • Setting up debugging in VS Code.
  • Using source maps.
• Best Practices for Writing TypeScript:
  • Writing clear and maintainable types.
  • Avoiding `any` as much as possible.
  • Using strict mode.
  • Structuring your project.

Section 6: Practice and Building Projects

• Convert a small JavaScript project to TypeScript.
• Build a simple API with Node.js and Express using TypeScript.
• Build a small frontend application with a framework (React or Vue) using TypeScript.
• Implement a data structure (e.g., linked list, stack, queue) using TypeScript classes and generics.
• Explore and contribute to open-source TypeScript projects.
• Build a simple command-line tool using TypeScript.

Section 7: Staying Updated and Advanced Topics

• Following the TypeScript Community:
  • Official TypeScript documentation and blog.
  • TypeScript conferences and talks.
  • TypeScript social media channels and forums.
• Exploring New TypeScript Features:
  • Keeping up with new releases and features.
• Deep Dive into Type System:
  • Understanding advanced type inference.
  • Exploring the nuances of the type system.

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