Nexus/scripts/db-target-guard.mjs

import { URL } from "node:url";

export function formatDatabaseTarget(parsedUrl, databaseName) {
  return `${parsedUrl.protocol}//${decodeURIComponent(parsedUrl.username)}@${parsedUrl.hostname}${parsedUrl.port ? `:${parsedUrl.port}` : ""}/${databaseName}`;
}

export function inspectDatabaseUrl(rawUrl, expectedDatabase = "nexus") {
  if (!rawUrl) {
    throw new Error("DATABASE_URL is not configured.");
  }

  let parsedUrl;
  try {
    parsedUrl = new URL(rawUrl);
  } catch (error) {
    throw new Error(`DATABASE_URL is invalid: ${error instanceof Error ? error.message : String(error)}`);
  }

  const databaseName = parsedUrl.pathname.replace(/^\/+/, "");
  const target = formatDatabaseTarget(parsedUrl, databaseName);

  if (!databaseName) {
    throw new Error(`DATABASE_URL does not contain a database name. Target=${target}`);
  }

  if (databaseName !== expectedDatabase) {
    throw new Error(`Unexpected database target '${databaseName}'. Expected '${expectedDatabase}'. Target=${target}`);
  }

  return {
    databaseName,
    expectedDatabase,
    target,
  };
}

function collectPrismaCommandTokens(args) {
  const tokens = [];

  for (let index = 0; index < args.length; index += 1) {
    const arg = args[index];

    if (arg === "--") {
      break;
    }

    if (arg === "--schema" || arg === "--url" || arg === "--telemetry-information") {
      index += 1;
      continue;
    }

    if (arg.startsWith("-")) {
      continue;
    }

    tokens.push(arg);
  }

  return tokens;
}

export function shouldGuardPrismaCommand(args) {
  if (args.includes("--help") || args.includes("-h")) {
    return false;
  }

  const [command, subcommand] = collectPrismaCommandTokens(args);

  if (!command) {
    return false;
  }

  if (command === "db") {
    return subcommand === "push" || subcommand === "pull" || subcommand === "execute";
  }

  if (command === "migrate") {
    return true;
  }

  return command === "studio" || command === "introspect";
}

export function getExpectedDatabaseName() {
  return process.env.NEXUS_EXPECTED_DB_NAME?.trim() || "nexus";
}