build/lib/tsb/transpiler.ts/SwcTranspiler/transpile
class SwcTranspiler:	transpile(file: Vinyl): void {
		if (this._cmdLine.options.noEmit) {
			// not doing ANYTHING here
			return;
		}

		const tsSrc = String(file.contents);
		const t1 = Date.now();

		let options: swc.Options = SwcTranspiler._swcrcEsm;
		if (this._cmdLine.options.module === ts.ModuleKind.AMD) {
			const isAmd = /\n(import|export)/m.test(tsSrc);
			if (isAmd) {
				options = SwcTranspiler._swcrcAmd;
			}
		} else if (this._cmdLine.options.module === ts.ModuleKind.CommonJS) {
			options = SwcTranspiler._swcrcCommonJS;
		}

		this._jobs.push(swc.transform(tsSrc, options).then(output => {

			// check if output of a DTS-files isn't just "empty" and iff so
			// skip this file
			if (file.path.endsWith('.d.ts') && _isDefaultEmpty(output.code)) {
				return;
			}

			const outBase = this._cmdLine.options.outDir ?? file.base;
			const outPath = this._outputFileNames.getOutputFileName(file.path);

			this.onOutfile!(new Vinyl({
				path: outPath,
				base: outBase,
				contents: Buffer.from(output.code),
			}));

			this._logFn('Transpile', `swc took ${Date.now() - t1}ms for ${file.path}`);

		}).catch(err => {
			this._onError(err);
		}));
	}