javascript: Page 1

07 POSTS

Javascript 1

#web-performance#javascript#browser
I Grew Never-Executed JavaScript to 10MiB
How much do you lose when 10MiB of functions you never call ships to the browser? I ran 855 measurements to separate the cost created by bytes from the cost created by the shape of the code. Uncalled declarations cost about 21ms per MiB and did not grow when I slowed the CPU by 4x, while initialization code that runs the moment the file is read added 201ms per MiB to the main thread. With real libraries, merely importing a module was enough to evaluate it.
2026-09-1632 min read
#debugging#bundler#nextjs
Next.js Turbopack Turned One Singleton into Two: A Scope Hoisting Bug and a Circular Import
In a Next.js 16 Turbopack production build, a module-scope singleton became two live instances at runtime. Inside the same synchronous block, one condition contradicted the other, and responses that arrived in 30ms still timed out. This is the record of tracing the cause through the bundle output: a partial scope hoisting merge, a circular import, an upstream bug that had already been fixed, and the single-variable experiment I ran too late.
2026-08-1916 min read
#nodejs#security#javascript
The Pitfalls of Node.js vm Module: Why It's Not a Sandbox
A preview of section 5.2 (Pitfalls of the vm Module) from the upcoming Node.js Deep Dive book.
2026-02-2714 min read
#memory#web-performance#design-patterns
Preventing Memory Leaks with IntersectionObserver Singleton Pattern and WeakMap
How to efficiently observe hundreds of elements while preventing memory leaks
2026-01-1713 min read
#web-performance#memory#async
How to Efficiently Process Massive JSON Responses
How to survive when JSON.parse() becomes overwhelming
2026-01-1118 min read
#error-handling#javascript#async
Handling Uncaught Async Errors in JavaScript Correctly
Why try...catch misses errors thrown in async functions, and how to handle every case: IIFEs, forEach, promise chains, constructors, event listeners, and global safety nets.
2021-08-2312 min read
#compiler#javascript
Understanding AST for JavaScript Developers (2026 Update)
A comprehensive guide covering AST concepts, parsing process, key node types, and practical usage in tools like Babel and ESLint.
2021-05-1013 min read

07 POSTS

Javascript 1

#web-performance#javascript#browser
I Grew Never-Executed JavaScript to 10MiB
How much do you lose when 10MiB of functions you never call ships to the browser? I ran 855 measurements to separate the cost created by bytes from the cost created by the shape of the code. Uncalled declarations cost about 21ms per MiB and did not grow when I slowed the CPU by 4x, while initialization code that runs the moment the file is read added 201ms per MiB to the main thread. With real libraries, merely importing a module was enough to evaluate it.
2026-09-1632 min read
#debugging#bundler#nextjs
Next.js Turbopack Turned One Singleton into Two: A Scope Hoisting Bug and a Circular Import
In a Next.js 16 Turbopack production build, a module-scope singleton became two live instances at runtime. Inside the same synchronous block, one condition contradicted the other, and responses that arrived in 30ms still timed out. This is the record of tracing the cause through the bundle output: a partial scope hoisting merge, a circular import, an upstream bug that had already been fixed, and the single-variable experiment I ran too late.
2026-08-1916 min read
#nodejs#security#javascript
The Pitfalls of Node.js vm Module: Why It's Not a Sandbox
A preview of section 5.2 (Pitfalls of the vm Module) from the upcoming Node.js Deep Dive book.
2026-02-2714 min read
#memory#web-performance#design-patterns
Preventing Memory Leaks with IntersectionObserver Singleton Pattern and WeakMap
How to efficiently observe hundreds of elements while preventing memory leaks
2026-01-1713 min read
#web-performance#memory#async
How to Efficiently Process Massive JSON Responses
How to survive when JSON.parse() becomes overwhelming
2026-01-1118 min read
#error-handling#javascript#async
Handling Uncaught Async Errors in JavaScript Correctly
Why try...catch misses errors thrown in async functions, and how to handle every case: IIFEs, forEach, promise chains, constructors, event listeners, and global safety nets.
2021-08-2312 min read
#compiler#javascript
Understanding AST for JavaScript Developers (2026 Update)
A comprehensive guide covering AST concepts, parsing process, key node types, and practical usage in tools like Babel and ESLint.
2021-05-1013 min read

Tweaks

Javascript 1

I Grew Never-Executed JavaScript to 10MiB

Next.js Turbopack Turned One Singleton into Two: A Scope Hoisting Bug and a Circular Import

The Pitfalls of Node.js vm Module: Why It's Not a Sandbox

Preventing Memory Leaks with IntersectionObserver Singleton Pattern and WeakMap

How to Efficiently Process Massive JSON Responses

Handling Uncaught Async Errors in JavaScript Correctly

Understanding AST for JavaScript Developers (2026 Update)

Tweaks

Javascript 1

I Grew Never-Executed JavaScript to 10MiB

Next.js Turbopack Turned One Singleton into Two: A Scope Hoisting Bug and a Circular Import

The Pitfalls of Node.js vm Module: Why It's Not a Sandbox

Preventing Memory Leaks with IntersectionObserver Singleton Pattern and WeakMap

How to Efficiently Process Massive JSON Responses

Handling Uncaught Async Errors in JavaScript Correctly

Understanding AST for JavaScript Developers (2026 Update)