How to Extract AST of given Typescript code using the open source Typescript compiler code?

Question

As it is known that Typescript is completely opensource now. which is available at Tyescript. I am building an application that will get Typescript code as input and give output the AST of the given code. Provide me a proper way to extract this AST(Abstract Syntax Tree) of input Typescript code rather than comppliling it and converting it into Javascript.

Answer 1

Basic code:

const fileNames = ["C:\\MyFile.ts"];
const compilerOptions: ts.CompilerOptions = {
    // compiler options go here if any...
    // look at ts.CompilerOptions to see what's available
};
const program = ts.createProgram(fileNames, compilerOptions);
const typeChecker = program.getTypeChecker();
const sourceFiles = program.getSourceFiles();

sourceFiles.filter(f => /MyFile\.ts$/.test(f.fileName)).forEach(sourceFile => {
    ts.forEachChild(sourceFile, node => {
        const declaration = node as ts.Declaration;
        if (declaration.name) {
            console.log(declaration.name.getText());
        }
    });
});

So if you provided that with a C:\MyFile.ts like:

class MyClass {}
interface MyInterface {}

It would output MyClass and MyInterface.

Figuring out everything beyond what I've just shown is a lot of work. It might be more beneficial for you to look at and/or help contribute to this work in progress.