TypeScript compiler API basics - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the main purpose of the TypeScript Compiler API?

It allows developers to programmatically interact with the TypeScript compiler to parse, analyze, and transform TypeScript code.

beginner

Which TypeScript module do you import to use the Compiler API?

You import the 'typescript' module, usually as <code>import * as ts from 'typescript';</code>.

intermediate

What does the ts.createSourceFile function do?

It creates a SourceFile object by parsing TypeScript code text, which represents the code's structure for analysis or transformation.

intermediate

How can you traverse the syntax tree created by the TypeScript compiler API?

You use recursive functions with ts.forEachChild to visit each node in the syntax tree.

advanced

What is the role of ts.createProgram in the Compiler API?

It creates a program that represents a complete compilation context, including multiple source files and compiler options.

Which function is used to parse TypeScript code into a syntax tree?

A ts.createProgram

B ts.compile

C ts.forEachChild

D ts.createSourceFile

ts.createSourceFile parses code text into a syntax tree representation.

What does ts.forEachChild help you do?

A Compile TypeScript code to JavaScript

B Traverse each child node of a syntax tree node

C Create a new source file

D Set compiler options

ts.forEachChild is used to visit each child node in the syntax tree.

Which object represents a full compilation context in the TypeScript Compiler API?

A Node

B SourceFile

C Program

D CompilerHost

Program represents the entire compilation including multiple files and options.

How do you import the TypeScript Compiler API in your code?

A import * as ts from 'typescript';

B const ts = require('typescript');

C import ts from 'ts';

D import typescript from 'ts-api';

The standard way is import * as ts from 'typescript';.

What is the first step to analyze TypeScript code using the Compiler API?

A Parse code with createSourceFile

B Emit JavaScript output

C Traverse nodes with forEachChild

D Create a Program

Parsing code with createSourceFile gives you the syntax tree to analyze.

Explain how to parse and traverse TypeScript code using the Compiler API.

Think about how you read a book page by page and word by word.

Describe the role of a Program in the TypeScript Compiler API.

Imagine a Program as the whole project, not just one file.