[BUG]: dd-trace appears to initialize before call to init()

[ronjouch]

Tracer Version(s)

5.33.0, 5.35.0

Node.js Version(s)

22.13.1

Bug Report

Documentation says that there are 2 options to Import and initialize the tracer:

1. In-JS, const tracer = require('dd-trace').init();
2. Cmdline flag, node --require dd-trace/init app.js

However, I observe that dd-trace instrumentation is initialized even when I do not call .init(). Is this expected? Am I doing something wrong?

Reproduction Code

With this first listing, I observe that dd-trace instrumentation unexpectedly happens even when DD_TRACE_ENABLED is unset:

const { tracer } = require('dd-trace');
if (process.env.NODE_ENV === 'production' && process.env.DD_TRACE_ENABLED === 'true') {
  tracer.init();
}
export const DD_TRACER = tracer;

---

However, with this second listing below, I observe that dd-trace instrumentation satisfyingly does not happen when DD_TRACE_ENABLED is unset:

export let DD_TRACER;
if (process.env.NODE_ENV === 'production' && process.env.DD_TRACE_ENABLED === 'true') {
  const { tracer } = require('dd-trace');
  tracer.init();

  DD_TRACER = tracer;
}

---

It follows that it looks like instrumentation happens at import/require time. But this contradicts your documentation, which says that instrumentation happens at .init() time. Right? Or is it “auto-initialized” because of something I do? Or am I missing something?

Also, regarding “what makes you say that instrumentation happens?” : I believe instrumentation happens because dd-trace causes a crashes in the app test suite (where of course dd-trace shouldn't run, because process.env.NODE_ENV !== 'production') since this change of dd-trace 5.33.0 in packages/datadog-instrumentations/src/aws-sdk.js, where name = name.replaceAll(' ', '') legit crashes on name being undefined (“legit” because dd-trace shouldn't be running when running tests!).

To reformulate, this change made me realize that dd-trace instrumentation was unexpectedly happening when running the tests, and here I am trying to understand why.

Thanks for the halp 🙂.

Error Logs

No response

Tracer Config

No response

Operating System

Debian 6.12.12-1 x86_64

Bundling

No Bundling