the first part of typescript analyze process.

tiny-tsc-intro.ts

import {
	createCompilerHost,
	createProgram,
	Diagnostic,
	formatDiagnostic,
	FormatDiagnosticsHost,
	getParsedCommandLineOfConfigFile,
	ParseConfigFileHost,
	ParsedCommandLine,
	Program,
	sys,
} from 'typescript';
import { normalize } from 'path';

const program = createProgramConfigByTsConfig('./src/tsconfig.json');

for (const file of program.getSourceFiles()) {
	console.log(file.fileName);
}

function createProgramConfigByTsConfig(tsconfigPath: string): Program {
	const myFormatDiagnosticsHost: FormatDiagnosticsHost = {
		getCurrentDirectory : sys.getCurrentDirectory,
		getCanonicalFileName: normalize,
		getNewLine(): string {
			return sys.newLine;
		},
	};

	const createConfigFileHost: ParseConfigFileHost = {
		onUnRecoverableConfigFileDiagnostic(diagnostic: Diagnostic) {
			console.error(formatDiagnostic(diagnostic, myFormatDiagnosticsHost));
		},
		useCaseSensitiveFileNames: false,
		readDirectory            : sys.readDirectory,
		fileExists               : sys.fileExists,
		readFile                 : sys.readFile,
		getCurrentDirectory      : sys.getCurrentDirectory,
	};

	const configParseResult: ParsedCommandLine = getParsedCommandLineOfConfigFile(tsconfigPath, {}, createConfigFileHost);

	const host = createCompilerHost(configParseResult.options, true);
	return createProgram(configParseResult.fileNames, configParseResult.options, host);
}