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menu_book Course Curriculum (Bun) expand_more

Runtime Basics

Run JavaScript file Run TypeScript file bun --watch bun --hot Environment variables Bun.version Bun.main process compatibility Import ES modules CommonJS compatibility

Package Manager

bun install bun add bun remove bun update bun pm ls bun.lock Workspaces Overrides and resolutions Trusted dependencies Global packages

Scripts & Tooling

bun run Package scripts bunx Shell scripts with Bun bun init bun create bun upgrade bun --bun Preload modules CLI arguments

Files & Streams

Bun.file File text File json File arrayBuffer Bun.write ReadableStream Blob handling File exists check stdin reading stdout writing

HTTP & Web APIs

Bun.serve Request routing Response JSON URL parsing FormData handling Cookies WebSocket upgrade Server WebSocket AbortSignal Fetch API

SQLite & Data

bun:sqlite Database Prepare statement Run statement Query all rows Query single row Transactions Named parameters SQLite pragmas Serialize access Close database

Testing

bun test expect equality Async tests Test hooks Mock functions Spy functions Snapshots Test timeouts Parameterized tests Coverage

Bundler & Advanced

bun build Build entrypoints Build target Minification Source maps Loaders Plugins Workers FFI basics Production deployment

Bun / Files & Streams

File exists check

Learn File exists check in Bun with a focused explanation, a topic-specific example, edge guidance, and a mastery check.

12 min read • Intermediate

bun-038.ts

ts

console.log(await Bun.file("./settings.json").exists());

What to watch

Content source & attribution

Original Syntaxis Content · Original Syntaxis Content

Lesson quizzes

File exists check Mastery Check →