getProjectRoot.ts

const __dirname = (() => {
    const { url: urlStr } = import.meta;
    const url = new URL(urlStr);
    const __filename = (url.protocol === "file:" ? url.pathname : urlStr)
        .replace(/[/][^/]*$/, '');

    const isWindows = (() => {

        let NATIVE_OS: typeof Deno.build.os = "linux";
        // eslint-disable-next-line @typescript-eslint/no-explicit-any
        const navigator = (globalThis as any).navigator;
        if (globalThis.Deno != null) {
            NATIVE_OS = Deno.build.os;
        } else if (navigator?.appVersion?.includes?.("Win") ?? false) {
            NATIVE_OS = "windows";
        }

        return NATIVE_OS == "windows";

    })();

    return isWindows ?
        __filename.split("/").join("\\").substring(1) :
        __filename;
})();

import * as fs from "node:fs";
import * as path from "node:path";

function getProjectRootRec(dirPath: string): string {
    if (fs.existsSync(path.join(dirPath, "package.json"))) {
        return dirPath;
    }
    return getProjectRootRec(path.join(dirPath, ".."));
}

let result: string | undefined = undefined;

export function getProjectRoot(): string {
    if (result !== undefined) {
        return result;
    }

    return (result = getProjectRootRec(__dirname));
}