debugging-strategies

Configure a launch.json file with type 'node', request 'launch', and point the program field to your entry file. You can then set breakpoints, inspect variables, and step through code directly in the editor.

Use git bisect: mark the current commit as bad and a known working commit as good, then git checks out middle commits for you to test. Marking each as good or bad narrows the range until the offending commit is found.

Use the built-in breakpoint() function or pdb for interactive debugging, and cProfile with pstats to profile performance and identify the slowest functions. The ipdb package provides an enhanced debugger interface.

Take heap snapshots in Chrome DevTools before and after the suspected action, then compare them to find retained objects. In Node.js, monitor process.memoryUsage() and generate heap dumps with v8.writeHeapSnapshot().

Intermittent bugs usually stem from race conditions, timing dependencies, or uncontrolled external state. Add extensive timing and state-transition logging, then stress test with varied timing and load to make the failure reproducible.

Use a debugger when you need to inspect complex state, step through execution flow, or examine call stacks without modifying code. Console logging works for quick value checks but becomes unwieldy for multi-layered logic.