Typescript Compiler API
// ts-morph
// 浏览器运行时？
The compiler API has a few main components:
- A `Program` which is the TypeScript terminology for your whole application
- A `CompilerHost` which represents the users' system, with an API for reading files, checking directories and case sensitivity etc.
- Many `SourceFiles` which represent each source file in the application, hosting both the text and TypeScript AST
createProgram
createWatchProgram
createSourceFile
使用工厂函数创建 AST，使用工厂函数从 AST 输出 ts 文件
transpileModule // 直接输出 js