# 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
```javascript
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
```javascript
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

```bash
# 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! 🎉

---

*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"*