Function createVirtualProgram

src/transpilation/index.ts:45–87

(input: Record<string, string>, options: CompilerOptions = {})

/** @internal */
export function createVirtualProgram(input: Record<string, string>, options: CompilerOptions = {}): ts.Program {
    const normalizedFiles: Record<string, string> = {};
    for (const [path, file] of Object.entries(input)) {
        normalizedFiles[normalizeSlashes(path)] = file;
    }
    const compilerHost: ts.CompilerHost = {
        fileExists: fileName => fileName in normalizedFiles || ts.sys.fileExists(fileName),
        getCanonicalFileName: fileName => fileName,
        getCurrentDirectory: () => "",
        getDefaultLibFileName: ts.getDefaultLibFileName,
        readFile: () => "",
        getNewLine: () => "\n",
        useCaseSensitiveFileNames: () => false,
        writeFile() {},

        getSourceFile(fileName) {
            if (fileName in normalizedFiles) {
                return ts.createSourceFile(fileName, normalizedFiles[fileName], ts.ScriptTarget.Latest, false);
            }

            let filePath: string | undefined;

            if (fileName.startsWith("lib.")) {
                const typeScriptDir = path.dirname(require.resolve("typescript"));
                filePath = path.join(typeScriptDir, fileName);
            }

            if (fileName.includes("language-extensions")) {
                const dtsName = fileName.replace(/(\.d)?(\.ts)$/, ".d.ts");
                filePath = path.resolve(dtsName);
            }

            if (filePath !== undefined) {
                if (libCache[fileName]) return libCache[fileName];
                const content = fs.readFileSync(filePath, "utf8");
                libCache[fileName] = ts.createSourceFile(filePath, content, ts.ScriptTarget.Latest, false);
                return libCache[fileName];
            }
        },
    };

    return ts.createProgram(Object.keys(normalizedFiles), options, compilerHost);
}

export interface TranspileVirtualProjectResult {
    diagnostics: ts.Diagnostic[];