False positive pushstate warnings with SvelteKit

[AliTahir-101]

Is there an existing issue for this?

• I have checked for existing issues https://github.com/getsentry/sentry-javascript/issues
• I have reviewed the documentation https://docs.sentry.io/
• I am using the latest SDK release https://github.com/getsentry/sentry-javascript/releases

How do you use Sentry?

Sentry Saas (sentry.io)

Which SDK are you using?

@sentry/sveltekit

SDK Version

8.32.0

Framework Version

sveltekit 2.5.28

Link to Sentry event

No response

Reproduction Example/SDK Setup

sveltejs/kit#12177

Steps to Reproduce

Just start a sveltekit app with sentry and on first page load you will see the warning.

seems like initiating here // node_modules/@sentry-internal/browser-utils/build/esm/instrument/history.js

[Warning] Avoid using history.pushState(...)andhistory.replaceState(...)as these will conflict with SvelteKit's router. Use thepushStateandreplaceStateimports from$app/navigation instead. (client.js, line xxx)

Expected Result

No wanning while using svelte app navigation.

Actual Result

[Warning] Avoid using history.pushState(...)andhistory.replaceState(...)as these will conflict with SvelteKit's router. Use thepushStateandreplaceStateimports from$app/navigation instead. (client.js, line xxx)

[AliTahir-101]

Possible fix: // node_modules/@sentry-internal/browser-utils/build/esm/instrument/history.js

import { addHandler, maybeInstrument, supportsHistory, triggerHandlers, fill } from '@sentry/utils';
import { WINDOW } from '../types.js';

let lastHref;

// Check if SvelteKit is in the environment
const isSvelteKit = (() => {
  try {
    return typeof window !== 'undefined' && window.__sveltekit_dev !== undefined;
  } catch {
    return false;
  }
})();

/**
 * Add an instrumentation handler for when a fetch request happens.
 * The handler function is called once when the request starts and once when it ends,
 * which can be identified by checking if it has an `endTimestamp`.
 *
 * Use at your own risk, this might break without changelog notice, only used internally.
 * @hidden
 */
function addHistoryInstrumentationHandler(handler) {
  const type = 'history';
  addHandler(type, handler);
  maybeInstrument(type, instrumentHistory);
}

function instrumentHistory() {
  if (!supportsHistory()) {
    return;
  }

  const oldOnPopState = WINDOW.onpopstate;
  WINDOW.onpopstate = function ( ...args) {
    const to = WINDOW.location.href;
    // keep track of the current URL state, as we always receive only the updated state
    const from = lastHref;
    lastHref = to;
    const handlerData = { from, to };
    triggerHandlers('history', handlerData);
    if (oldOnPopState) {
      // Apparently this can throw in Firefox when incorrectly implemented plugin is installed.
      // https://github.com/getsentry/sentry-javascript/issues/3344
      // https://github.com/bugsnag/bugsnag-js/issues/469
      try {
        return oldOnPopState.apply(this, args);
      } catch (_oO) {
        // no-empty
      }
    }
  };

  function historyReplacementFunction(originalHistoryFunction) {
    return function ( ...args) {
      const url = args.length > 2 ? args[2] : undefined;
      if (url) {
        // coerce to string (this is what pushState does)
        const from = lastHref;
        const to = String(url);
        // keep track of the current URL state, as we always receive only the updated state
        lastHref = to;
        const handlerData = { from, to };
        triggerHandlers('history', handlerData);
      }

      // Use SvelteKit navigation if in SvelteKit environment
      if (isSvelteKit) {
        try {
          if (originalHistoryFunction.name === 'pushState') {
            import('$app/navigation')
              .then(({ pushState }) => pushState(url))
              .catch(err => console.error('Failed to push state:', err));
            return; // Ensure to exit after calling pushState
          } else if (originalHistoryFunction.name === 'replaceState') {
            import('$app/navigation')
              .then(({ replaceState }) => replaceState(url))
              .catch(err => console.error('Failed to replace state:', err));
            return; // Ensure to exit after calling replaceState
          }
        } catch (err) {
          console.error(`Failed to import SvelteKit navigation for ${originalHistoryFunction.name}:`, err);
        }
      }


      // Fallback to native behavior
      return originalHistoryFunction.apply(this, args);
    };
  }

  fill(WINDOW.history, 'pushState', historyReplacementFunction);
  fill(WINDOW.history, 'replaceState', historyReplacementFunction);
}

export { addHistoryInstrumentationHandler };
//# sourceMappingURL=history.js.map

[Lms24]

Hi @AliTahir-101 thanks for writing in! I noticed this in a side project of mine also recently and wanted to follow up on it. I'll look into SvelteKit code to understand where this warning is triggered. Ideally, we find a way to work around this within the @sentry/sveltekit package. The suggested fix would increase bundle size for all browser SDKs so ideally we avoid that :)

[AliTahir-101]

Hi @AliTahir-101 thanks for writing in! I noticed this in a side project of mine also recently and wanted to follow up on it. I'll look into SvelteKit code to understand where this warning is triggered. Ideally, we find a way to work around this within the @sentry/sveltekit package. The suggested fix would increase bundle size for all browser SDKs so ideally we avoid that :)

Hey! My suggestion was meant to provide a quick workaround based on my observations, but I recognize that a more optimal solution would involve adjustments within the sentry/sveltekit package itself.

I’m currently focused on my project, so I haven’t had the time to dive deep into debugging the Sentry integration. I appreciate your efforts in finding a more suitable resolution, and I look forward to any updates you may have. Thank you!

[Lms24]

Can you confirm for me that this is only a problem in dev mode? From reading the sveltekit code around it, I think it should be limited to dev but I'd like to make sure that's the case

[AliTahir-101]

Can you confirm for me that this is only a problem in dev mode? From reading the sveltekit code around it, I think it should be limited to dev but I'd like to make sure that's the case

Yes brother it seems like it only shows the warning when NODE_ENV is not prod.

[Lms24]

Hey, so I found out why this is happening. The good news: This shouldn't impact any functionality. The bad news: I can't fix this in the SDK without degrading functionality. I think we need to make the check in sveltekit a bit more robust. Let me try if I get somewhere with this. I'll post my findings in the SvelteKit issue you linked.

[AliTahir-101]

Thank you for taking the time to look into this. I appreciate your efforts and look forward to any updates you may have!

[getsantry]

This issue has gone three weeks without activity. In another week, I will close it.

But! If you comment or otherwise update it, I will reset the clock, and if you remove the label Waiting for: Community, I will leave it alone ... forever!

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"A weed is but an unloved flower." ― Ella Wheeler Wilcox 🥀