index.ts

import * as ts from 'typescript';

let options = {
	stripInternal: true,
	target: ts.ScriptTarget.ES5,
	experimentalDecorators: true,
	listEmittedFiles: true
};

function transform(ctx: ts.TransformationContext): ts.Transformer<ts.SourceFile> {
	return (rootNode): ts.SourceFile => {
		const visitChildren: ts.Visitor = (node: ts.Node): ts.VisitResult<ts.Node> => {
			console.log('Node kind=', ts.SyntaxKind[node.kind]);
			node = ts.visitEachChild(node, visitChildren, ctx);
			if (ts.isMethodDeclaration(node)) {
				let methodDecl: ts.MethodDeclaration = <ts.MethodDeclaration> node;
				if (methodDecl && methodDecl.name) {
					let name = <ts.Identifier> methodDecl.name;
					let text = name.text;
					if (text === 'getFoo') {
						let newName: ts.Identifier = ts.createIdentifier('getFooBar');
						return ts.updateMethod(
							methodDecl,
							methodDecl.decorators,
							methodDecl.modifiers,
							methodDecl.asteriskToken,
							newName,
							methodDecl.questionToken,
							methodDecl.typeParameters,
							methodDecl.parameters,
							methodDecl.type,
							methodDecl.body
						);
					}
				}
			}
			return node;
		}
		return ts.visitNode(rootNode, visitChildren);
	}
}


const filePath = '/Users/keithstrickland/RedPill/NPM/ts-compiler-experiment/src/data/sample.ts';
const newFilePath = '/Users/keithstrickland/RedPill/NPM/ts-compiler-experiment/src/data/sample_transformed.ts';
const program = ts.createProgram(
	[filePath],
	options
);
const sourceFile = program.getSourceFile(filePath);
const result: ts.TransformationResult<ts.SourceFile> = ts.transform(sourceFile, [transform], options);
const transformedSourceFile: ts.SourceFile = result.transformed[0];
const newSource: ts.SourceFile = ts.createSourceFile(
	newFilePath,
	transformedSourceFile.getText(),
	ts.ScriptTarget.ES5,
	false,
	ts.ScriptKind.TS);
const printer: ts.Printer = ts.createPrinter({newLine: ts.NewLineKind.LineFeed});
printer.printFile(newSource);

sample.ts

export class foo {
	private _bar: string;

	get bar() {
		return this._bar;
	}

	set bar(bar) {
		this._bar = bar;
	}

	getFoo() { // Expect this method name to be changed to getFooBar
		return 'foo';
	}

	getBar() {
		return 'foo';
	}
}