Function getConfig

packages/ttypescript/src/patchCreateProgram.ts:115–138

(
    tsm: typeof ts,
    compilerOptions: ts.CompilerOptions,
    rootFileNames: ReadonlyArray<string>,
    defaultDir: string
)

}

function getConfig(
    tsm: typeof ts,
    compilerOptions: ts.CompilerOptions,
    rootFileNames: ReadonlyArray<string>,
    defaultDir: string
) {
    if (compilerOptions.configFilePath === undefined) {
        const dir = rootFileNames.length > 0 ? dirname(rootFileNames[0]) : defaultDir;
        const tsconfigPath = tsm.findConfigFile(dir, tsm.sys.fileExists);
        if (tsconfigPath) {
            const projectDir = dirname(tsconfigPath);
            const config = readConfig(tsm, tsconfigPath, dirname(tsconfigPath));
            compilerOptions = { ...config.options, ...compilerOptions };
            return {
                projectDir,
                compilerOptions,
            };
        }
    }
    return {
        projectDir: dirname(compilerOptions.configFilePath as string),
        compilerOptions,
    };
}

function readConfig(tsm: typeof ts, configFileNamePath: string, projectDir: string) {
    const result = tsm.readConfigFile(configFileNamePath, tsm.sys.readFile);