@swizzyweb/swerve-manager/src/utils/getFullImportPath.ts

swizzy-swerve is a bootstrapper for swizzy web services. This package will bootstrap and run independent swizzy web services.

// cross-runtime getFullImportPath.ts
import { promises as fs } from "node:fs";
import { pathToFileURL } from "node:url";

// Runtime detection
// @ts-ignore
const isDeno = typeof Deno !== "undefined" && "cwd" in Deno;
// @ts-ignore
const isBun = typeof Bun !== "undefined";
// @ts-ignore
const isNode = !isDeno && !isBun;

let join: (a: string, b: string) => string;
let cwd: () => string;
let fromFileUrl: (url: string) => string;

// --- Runtime-specific shims ---
if (isDeno) {
  // @ts-ignore
  // const path = await import("https://deno.land/std@0.203.0/path/mod.ts");

  const path = await import("node:path");
  join = path.join;
  const url = await import("node:url");
  // @ts-ignore
  cwd = Deno.cwd;
  fromFileUrl = url.fileURLToPath;
  //  fromFileUrl = path.fromFileUrl;
} else if (isNode) {
  const path = await import("node:path");
  const processMod = await import("node:process");
  const url = await import("node:url");
  join = path.join;
  cwd = processMod.cwd;
  fromFileUrl = url.fileURLToPath;
} else if (isBun) {
  const path = await import("path");
  join = path.join;
  cwd = () => process.cwd();
  fromFileUrl = (u: string) => new URL(u).pathname; // Bun auto normalizes
}

// --- Universal function ---
export async function getFullImportPath(
  importPathOrName: string,
): Promise<string> {
  let importPath: string;

  if (importPathOrName.startsWith(".")) {
    importPath = join(cwd(), importPathOrName);
  } else {
    importPath = importPathOrName;
  }

  if (importPathOrName === importPath) {
    // Turn into a full absolute path
    const fullUrl = new URL(importPath, import.meta.url).href;
    return fromFileUrl(fullUrl);
  }

  return importPath;
}

export async function resolvePackageEntry(pkgDir: string): Promise<string> {
  const pkgJsonPath = join(pkgDir, "package.json");
  let entry: string | undefined;

  try {
    const pkgJsonRaw = await fs.readFile(pkgJsonPath, "utf-8");
    const pkgJson = JSON.parse(pkgJsonRaw);

    if (pkgJson.exports && typeof pkgJson.exports === "string") {
      // Simple "exports": "./esm/index.js"
      entry = pkgJson.exports;
    } else if (pkgJson.module) {
      entry = pkgJson.module;
    } else if (pkgJson.main) {
      entry = pkgJson.main;
    }
  } catch {
    // no package.json, fallback below
  }

  if (!entry) {
    // fallback to index.js
    entry = "index.js";
  }

  const absPath = join(pkgDir, entry);
  return pathToFileURL(absPath).href; // usable in await import()
}