compiler.ts

import * as ts from 'typescript';
import * as chalk from 'chalk';

import { TransformFactoryFactory } from '.';

/**
 * Compile and return result TypeScript
 * @param filePath Path to file to compile
 */
export function compile(filePath: string, factoryFactories: TransformFactoryFactory[]) {
    const compilerOptions: ts.CompilerOptions = {
        target: ts.ScriptTarget.ES2017,
        module: ts.ModuleKind.ES2015,
    };

    const program = ts.createProgram([filePath], compilerOptions);
    const sourceFiles = program.getSourceFiles().filter(sf => !sf.isDeclarationFile);
    const typeChecker = program.getTypeChecker();

    const result = ts.transform(
        sourceFiles,
        factoryFactories.map(factoryFactory => factoryFactory(typeChecker), compilerOptions),
    );


    if (result.diagnostics && result.diagnostics.length) {
        console.log(chalk.yellow(`
        ======================= Diagnostics for ${filePath} =======================
        `));
        for (const diag of result.diagnostics) {
            if (diag.file && diag.start) {
                const pos = diag.file.getLineAndCharacterOfPosition(diag.start);
                console.log(`(${pos.line}, ${pos.character}) ${diag.messageText}`)
            }
        }
    }

    const printer = ts.createPrinter()

    // TODO: fix the index 0 access... What if program have multiple source files?
    return printer.printNode(ts.EmitHint.SourceFile, result.transformed[0], sourceFiles[0]);
}