JavaScript Forensics

Something terrible happened here. Traces of errors litter the floor; memory leaking from cracks in the ceiling. Someone lost their object context in the corner. Everything reeks of jank. In this session, a JavaScript error tracking expert breaks down a series of common and complex crimes against web applications. You’ll leave the session armed with techniques and tools to detect, diagnose, and fix your JavaScript web applications. Bring your bugs and let’s fix up our web.

Code examples:
https://github.com/toddhgardner/soliloquy

Checkout TrackJS Error Monitoring:
https://trackjs.com/javascript?utm_source=slides&utm_medium=speakerdeck&utm_term=forensics

Transcript

1. WANTED JavaScript Forensics Todd H Gardner @toddhgardner
2. Wild Wild Web
3. WANTED @toddhgardner JavaScript Outlaws
4. Soliloquy
5. {Track:js} https://trackjs.com JavaScript Error Monitoring
6. Scripty Joe WANTED Characteristics: Script Error Impact: Unknown Reward $5,00
8. Soliloquy
9. Scripty “Line 1” Joe Place of Origin: Characteristics: Associates: Browser Obfuscation Noisy 3rd party domains Apprehend with CORS and crossorigin attributes Remarks:
10. Jane Adsy WANTED Characteristics: getRandomAds is not defined Impact: global Reward $5,00
12. Soliloquy
13. Jane “3rd Party” Adsy Place of Origin: Characteristics: Associates: Unplanned Changes Sudden bursts of violence SaaS, Analytics, CDN Weigh risk vs value of 3rd party dependencies Remarks:
14. Clara Context WANTED Characteristics: Cannot read propert of undefined Impact: major Reward $5,00
15. Error Cannot read property ‘destroy’ of undefined User Click <button class=“js-delete-statement”>
16. Soliloquy
17. Clara “This&That” Context Place of Origin: Characteristics: Associates: Functional Args Not Defined Callbacks, Promises Can usually be discovered through test Remarks:
18. Dolly Data WANTED Characteristics: Substr is not a function Impact: isolated Reward $5,00
19. a.text.substr is not a function
20. Soliloquy
21. Dolly “Bad Shape” Data Place of Origin: Characteristics: Associates: Contract Changes Production Faults Separated Dev Teams Difficult to prevent with test Remarks:
22. Logan Noloaden WANTED Characteristics: INLINE_ADS is not a function Impact: major Reward $5,00
24. Soliloquy
25. Logan “404” Noloaden Place of Origin: Characteristics: Associates: Flaky Infrastructre 404, is undefined The Internet Verify load before invoking external functions. Remarks:
26. Mabrowser Crashin WANTED Characteristics: Slow perf, browser crash Impact: catastrophic Reward $5,00
28. Soliloquy
29. Mabrowser Crashin Place of Origin: Characteristics: Associates: Detached Elements Slow Perf, Crashing Clientside Rendering Periodic scanning for memory leaks. Remarks:
30. CAPTURED @toddhgardner JavaScript Outlaws Scripty Joe Jane Adsy Clara Context Dolly Data Logan Noloaden Mabrowser Crashi
31. {Track:js} https://trackjs.com JavaScript Error Monitoring
32. User Activity AJAX History Console Logs Browser Info Inline Source Async Traces
33. WANTED JavaScript Forensics Todd H Gardner @toddhgardner todd@trackjs.com