`testcontainers@12.0.2` (patch) pulls in ESM-only `archiver@8`, breaking CommonJS/Jest consumers

[dh-seanmurphy]

Summary

The patch release 12.0.1 → 12.0.2 bumped the archiver dependency from ^7 to ^8.0.0. archiver@8.0.0 is an ESM-only major release ("type": "module", single "exports": "./index.js" with no require condition, CJS build dropped).

testcontainers is itself compiled to CommonJS and consumes archiver via require("archiver"). require()-ing an ESM-only package is not supported by Jest's CommonJS module runtime, so any consumer running testcontainers under Jest now fails to even load the module.

Introducing an ESM-only major of a dependency is a breaking change for CommonJS consumers and shouldn't ship in a patch release. Jest's runtime does not honor Node's require(esm) interop, so this breaks Jest test suites that use testcontainers — independent of Node version.

Reproduction

repro fails at module load time (require("testcontainers") → require("archiver")), before any container is created.

package.json

{
  "name": "tc-esm-repro",
  "devDependencies": {
    "jest": "30.4.2",
    "testcontainers": "12.0.2"
  }
}

repro.test.js

// Fails to even load the module — no Docker required.
require("testcontainers");

test("testcontainers loads under Jest", () => {});

Run:

npm install
npx jest

Result:

SyntaxError: Cannot use import statement outside a module

  .../node_modules/archiver/index.js:1
  import Archiver from "./lib/core.js";
  ^^^^^^
  at .../testcontainers/build/generic-container/started-generic-container.js:7

Changing only "testcontainers": "12.0.2" → "12.0.1" and re-running npx jest makes the suite pass. The sole difference is archiver@8 (ESM-only) vs archiver@7 (CJS).

Environment

• testcontainers: 12.0.2
• archiver: 8.0.0 (ESM-only)
• Jest: 30.4.2
• node: 24.16.0

Suggested resolution

• Revert to archiver@^7 in a 12.0.x patch and ship the archiver@8 upgrade as a minor or major instead

Extra information

Issue report generated with assistance from Claude.

[cristianrgreco]

Thanks for raising @dh-seanmurphy. This was indeed a miss from me. We have smoke tests for CJS/ESM as part of every build which passed but I was unaware that Jest has its own CJS runtime that behaves differently.

The linked PR reverts the archiver upgrade and adds Jest/Vitest specific smoke tests to avoid this happening again in future.

Will look at getting this merged/released ASAP.

[cristianrgreco]

@dh-seanmurphy Fix released in 12.0.3. Thanks again for raising.

[dh-seanmurphy]

Thanks for reacting so quickly @cristianrgreco - great job!