github.com/microsoft/deoptexplorer-vscode ↗
A VS Code extension to visualize deoptimizations in your JavaScript and TypeScript code running in V8 (i.e., NodeJS, Edge, Chrome, etc.).
An animated visualization of microsoft/deoptexplorer-vscode's Git history from February 2022 to May 2023, built by 3 contributors. The codebase reached 478 lines, mostly TypeScript. The video runs 20 seconds.
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Language
TypeScript
Contributors
3
Lines of Code
478
From
2022-02-22
To
2023-05-12
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About microsoft/deoptexplorer-vscode
Deopt Explorer is a VS Code extension that helps developers understand and analyze performance characteristics of JavaScript and TypeScript code running in V8 environments like Node.js, Chrome, and Edge. The tool parses V8 trace logs generated with specific command-line flags and visualizes deoptimization events, inline cache evolution, function optimization states, V8 maps, and CPU profiling data directly within the editor.
The extension provides multiple views for analyzing V8 internals, including CPU profile trees similar to Chrome DevTools with top-down, bottom-up, and flat views. Developers can inspect how inline caches evolve as different data types are encountered, view deoptimization events that cause the compiler to fall back to interpretation, track whether functions are optimized or interpreted, and examine V8's internal object maps to investigate polymorphism issues. The tool adds editor highlighting and diagnostics to show optimization hints directly in source code.
Users generate V8 logs using Node.js command-line options or the npm package dexnode, then open the log files in VS Code via the extension's command. The extension is designed for advanced users with V8 knowledge who want to investigate performance regressions through low-level compiler behavior rather than receive automated optimization recommendations.
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