feat(node): Add ignoreLayers and ignoreLayersType options to express instrumentation

[AbhiPrasad]

This PR adds two new options to the Express integration: ignoreLayers and ignoreLayersType, bringing it to feature parity with the underlying OpenTelemetry instrumentation.

resolves #16555

Changes

• Added ignoreLayers option to ignore specific Express layers based on their path
• Added ignoreLayersType option to ignore specific Express layers based on their type
• Added comprehensive tests for both options
• Updated JSDoc documentation with usage examples

Usage

Ignore layers by path

The ignoreLayers option accepts an array of elements that can be:

• string for full match of the path
• RegExp for partial match of the path
• function in the form of (path) => boolean for custom logic

const Sentry = require('@sentry/node');

Sentry.init({
  integrations: [
    Sentry.expressIntegration({
      ignoreLayers: [
        '/health',              // Ignore exact path
        /^\/internal/,          // Ignore paths starting with /internal
        (path) => path.includes('admin') // Custom logic
      ]
    })
  ],
});

Ignore layers by type

The ignoreLayersType option accepts an array of the following strings:

• router - for express.Router()
• middleware - for middleware functions
• request_handler - for request handlers (anything that's not a router or middleware)

const Sentry = require('@sentry/node');

Sentry.init({
  integrations: [
    Sentry.expressIntegration({
      ignoreLayersType: ['middleware'] // Ignore all middleware spans
    })
  ],
});

Combining both options

Both options can be used together:

const Sentry = require('@sentry/node');

Sentry.init({
  integrations: [
    Sentry.expressIntegration({
      ignoreLayers: ['/health', '/metrics', /^\/internal/],
      ignoreLayersType: ['middleware']
    })
  ],
});

[github-actions]

size-limit report 📦

Path	Size	% Change	Change
@sentry/browser	23.88 kB	-	-
@sentry/browser - with treeshaking flags	22.35 kB	-	-
@sentry/browser (incl. Tracing)	39.75 kB	-	-
@sentry/browser (incl. Tracing, Replay)	77.88 kB	-	-
@sentry/browser (incl. Tracing, Replay) - with treeshaking flags	67.61 kB	-	-
@sentry/browser (incl. Tracing, Replay with Canvas)	82.58 kB	-	-
@sentry/browser (incl. Tracing, Replay, Feedback)	94.68 kB	-	-
@sentry/browser (incl. Feedback)	40.58 kB	-	-
@sentry/browser (incl. sendFeedback)	28.56 kB	-	-
@sentry/browser (incl. FeedbackAsync)	33.46 kB	-	-
@sentry/react	25.61 kB	-	-
@sentry/react (incl. Tracing)	41.72 kB	-	-
@sentry/vue	28.31 kB	-	-
@sentry/vue (incl. Tracing)	41.53 kB	-	-
@sentry/svelte	23.9 kB	-	-
CDN Bundle	25.18 kB	-	-
CDN Bundle (incl. Tracing)	39.44 kB	-	-
CDN Bundle (incl. Tracing, Replay)	75.44 kB	-	-
CDN Bundle (incl. Tracing, Replay, Feedback)	80.91 kB	-	-
CDN Bundle - uncompressed	73.54 kB	-	-
CDN Bundle (incl. Tracing) - uncompressed	116.99 kB	-	-
CDN Bundle (incl. Tracing, Replay) - uncompressed	231.18 kB	-	-
CDN Bundle (incl. Tracing, Replay, Feedback) - uncompressed	243.99 kB	-	-
@sentry/nextjs (client)	43.32 kB	-	-
@sentry/sveltekit (client)	40.2 kB	-	-
@sentry/node	167.62 kB	+0.02%	+21 B 🔺
@sentry/node - without tracing	100.3 kB	-	-
@sentry/aws-serverless	128.41 kB	-	-

View base workflow run

[eliliam]

Until this is merged, is there any workaround to disable the Express middlewares from the default list while keeping all other default middlewares?

[AbhiPrasad]

@eliliam you can use our new ignoreSpans config introduced with 10.2.0: https://github.com/getsentry/sentry-javascript/releases/tag/10.2.0