bun.sh/STATUS.md

Node.js SQLite API Implementation Status

Overview

This document tracks the implementation of node:sqlite support in Bun to match the Node.js SQLite API. The implementation follows Bun's architectural patterns using JavaScriptCore (JSC) bindings and native modules.

✅ Actually Working Stuff

1. Module Loading & Constructor Export ✅ (Finally!)

• Module Loading: require('node:sqlite') works without crashing
• Constructor Export: new sqlite.DatabaseSync() actually works now
• Class Architecture: Proper JSC class structure with Prototype/Constructor/Instance pattern
• Build System: Compiles successfully (though took way too many iterations)

2. JSC Integration ✅

• LazyClassStructure Pattern: Applied X509Certificate pattern correctly after several failed attempts
• Memory Management: Proper ISO subspaces and garbage collection hooks
• Module Registration: Added to builtin module registry and enum generation
• Static Properties: Removed assertion conflicts by NOT using HasStaticPropertyTable

🤷‍♂️ What We Actually Have

The Good News

• The module loads
• The constructor can be instantiated
• No more "assertion failed" crashes during startup
• All the scaffolding is in place
• Follows Bun's architectural patterns properly

The Reality Check

• Zero SQLite functionality: All methods return undefined
• No database operations: Can't open, read, write, or query anything
• Placeholder methods: open(), close(), exec(), prepare() do absolutely nothing
• No error handling: Will probably explode if you try to do real work
• StatementSync: Completely unimplemented beyond the constructor

🔍 The Brutal Truth About What We Accomplished

What Took Forever (Constructor Export Issue)

• 3+ iterations trying different JSC patterns
• Multiple assertion failures from HasStaticPropertyTable misconfigurations
• Hours debugging LazyClassStructure timing issues
• Final solution: Literally just follow the X509Certificate pattern exactly
• Key insight: Don't try to be clever, copy what works

Files That Actually Matter

• JSNodeSQLiteDatabaseSyncPrototype.{h,cpp} - Object prototype (mostly empty)
• JSNodeSQLiteDatabaseSyncConstructor.{h,cpp} - Function prototype (works!)
• JSNodeSQLiteDatabaseSync.{h,cpp} - Main class (has SQLite* member, does nothing with it)
• NodeSQLiteModule.h - Native module exports (uses LazyClassStructure correctly)
• isBuiltinModule.cpp - Module registry (needed for require() to work)

What We Learned The Hard Way

1. JSC is picky: Structure flags must match exactly what you declare
2. Timing matters: LazyClassStructure can't be accessed during certain init phases
3. Copy existing patterns: Don't reinvent, just follow X509Certificate exactly
4. Assertions are your friend: When JSC crashes, it's usually a structure mismatch

⚠️ Current Status: "It Compiles and Runs"

What Works Right Now

const sqlite = require('node:sqlite');  // ✅ Loads
const db = new sqlite.DatabaseSync();   // ✅ Creates object
console.log(typeof db.open);            // ✅ "function" 
db.open();                               // ✅ Returns undefined, does nothing

What Definitely Doesn't Work

db.open('my.db');                        // ❌ Ignores filename, does nothing
const stmt = db.prepare('SELECT 1');    // ❌ Returns undefined instead of statement
stmt.get();                              // ❌ stmt is undefined, will crash

🎯 What Actually Needs To Happen Next

The Real Work (Implementing SQLite)

1. DatabaseSync.open(filename): Actually call sqlite3_open()
2. DatabaseSync.exec(sql): Actually call sqlite3_exec()
3. DatabaseSync.prepare(sql): Return a real StatementSync object
4. StatementSync methods: run(), get(), all(), iterate() - none exist
5. Error handling: Map SQLite errors to JavaScript exceptions
6. Parameter binding: Support ? placeholders in SQL
7. Result handling: Convert SQLite results to JavaScript objects

Testing Reality Check

• No real tests: Just "does it load without crashing"
• Node.js compatibility: Probably fails every single test
• Edge cases: Haven't even thought about them yet
• Memory leaks: Probably has them since we don't close SQLite handles

📊 Honest Assessment

Completion Percentage: ~15%

• ✅ Architecture (15%): JSC classes, module loading, build system
• ❌ Functionality (0%): No actual SQLite operations
• ❌ Testing (0%): No meaningful test coverage
• ❌ Compatibility (0%): Doesn't match Node.js behavior yet

Time Spent vs Value

• 90% of time: Fighting JSC assertion failures and class structure issues
• 10% of time: Actual SQLite functionality (which doesn't work)
• Result: A very well-architected module that does absolutely nothing

🔧 Development Commands

# Build (takes ~5 minutes, be patient)
bun bd

# Test what actually works (module loading)
/workspace/bun/build/debug/bun-debug -e "
  const sqlite = require('node:sqlite');
  console.log('Module loaded:', Object.keys(sqlite));
  const db = new sqlite.DatabaseSync();  
  console.log('Constructor works:', typeof db);
"

# Test what doesn't work (everything else)
/workspace/bun/build/debug/bun-debug -e "
  const sqlite = require('node:sqlite');
  const db = new sqlite.DatabaseSync();
  db.open('test.db');  // Does nothing
  console.log('Opened database... not really');
"

🤔 Lessons Learned

Technical Insights

1. JSC patterns are rigid: Follow existing examples exactly, don't improvise
2. LazyClassStructure is powerful: But only when used correctly
3. Build system complexity: Small changes require understanding the entire pipeline
4. Debugging is hard: JSC assertion failures are cryptic but usually structure-related

Development Philosophy

1. Get it working first: Architecture is worthless if it doesn't run
2. Copy successful patterns: X509Certificate saved the day
3. Incremental progress: Module loading → Constructor → Methods → Functionality
4. Honest documentation: Better to admit what doesn't work than pretend it does

🎯 Next Steps (For Someone Brave Enough)

Immediate (Actually Implement SQLite)

1. Fill in the JSNodeSQLiteDatabaseSync::open() method with real sqlite3_open() calls
2. Implement exec() with proper SQL execution and result handling
3. Create real StatementSync objects instead of returning undefined
4. Add basic error handling so it doesn't crash on invalid SQL

Short Term (Make It Usable)

1. Parameter binding for prepared statements
2. Result set handling for SELECT queries
3. Transaction support (begin/commit/rollback)
4. Basic Node.js compatibility testing

Long Term (Production Ready)

1. Full Node.js sqlite test suite compatibility
2. Performance optimization
3. Memory leak prevention
4. Edge case handling

🏁 Bottom Line

We have successfully implemented the hard part (JSC integration and module architecture) and none of the easy part (actual SQLite functionality). It's a solid foundation that does absolutely nothing useful yet.

The good news: Adding SQLite functionality should be straightforward now that the class structure is working. The bad news: That's still like 85% of the actual work.

But hey, at least it doesn't crash anymore! 🎉

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Status updated 2025-08-06 after implementing proper JSC class architecture
Previous status: "Constructor export assertion failures"
Current status: "Constructor works, SQLite functionality doesn't exist"
Next milestone: "Make it actually do something with databases"