// Compile `ts` files using transformer

// Originally comes from https://github.com/longlho/ts-transform-img

import ts from "typescript";

import fs from "fs";

import { createTransformerFactory } from "./src/transformer";

function formatDiagnostics(diagnostics: ReadonlyArray<ts.Diagnostic>) {

const messages: Array<string> = [];

for (const diagnostic of diagnostics) {

let signature: string;

if (diagnostic.file) {

const { line, character } = diagnostic.file.getLineAndCharacterOfPosition(

diagnostic.start!

);

signature = `${diagnostic.file!.fileName} (${line + 1},${character + 1})`;

} else {

signature = "(unknown)";

}

const message = ts.flattenDiagnosticMessageText(

diagnostic.messageText,

"\n"

);

messages.push(`[compile.ts] ${signature}: ${message}`);

}

return messages;

}

function readTsConfig(filename = "./tsconfig.json"): ts.CompilerOptions {

const tsConfig = ts.readConfigFile(filename, path =>

fs.readFileSync(path).toString()

);

if (tsConfig.error) {

throw new Error(formatDiagnostics([tsConfig.error]).join("\n"));

}

const basePath = __dirname;

const result = ts.convertCompilerOptionsFromJson(

tsConfig.config.compilerOptions,

basePath,

filename

);

if (result.errors.length > 0) {

throw new Error(formatDiagnostics(result.errors).join("\n"));

}

return result.options;

}

export function compile(

files: ReadonlyArray<string>,

options: ts.CompilerOptions = readTsConfig()

) {

const compilerHost = ts.createCompilerHost(options);

const program = ts.createProgram(files, options, compilerHost);

const emitResult = program.emit(undefined, undefined, undefined, undefined, {

before: [createTransformerFactory(program)]

});

const diagnostics = ts

.getPreEmitDiagnostics(program)

.concat(emitResult.diagnostics);

if (diagnostics.length > 0) {

throw new Error(formatDiagnostics(diagnostics).join("\n"));

}

}

if (require.main === module) {

const [_nodejs, _compiler_ts, ...args] = process.argv;

compile(args);

}