Hot Reloading - Live UI Updates for Anchor Program Changes

Overview

Hot Reloading keeps your testing UI synchronized with your Solana program code. When you make changes and rebuild your program, Testship automatically detects the updates and refreshes the interface - no manual restarts required.

How It Works

Automatic Detection

Testship watches for changes to:

Your program’s IDL file (target/idl/*.json)
Program binary (target/deploy/*.so)
Anchor configuration (Anchor.toml)
Account type definitions

When you run anchor build, Testship:

Detects the IDL has changed
Parses the new interface definition
Updates the UI to match
Preserves your current session state

Seamless Updates

The hot reload process is smooth:

UI updates without page refresh
Form inputs are preserved where possible
Account suggestions remain available
Transaction history is maintained

Development Workflow

Traditional Workflow (Without Testship)

Make code changes
Run anchor build
Close test script
Restart test environment
Reconfigure test accounts
Re-enter test parameters
Execute test
⏱️ 5-10 minutes per iteration

With Hot Reloading

Make code changes
Run anchor build
UI updates automatically
Continue testing
⏱️ 30 seconds per iteration

Features

Intelligent UI Updates

Testship smartly handles different types of changes:

New Instructions

Automatically appear in the sidebar
Form generated instantly
Ready to test immediately

Modified Instructions

Updated parameter fields
Changed account requirements reflected
Previous inputs adapted when possible

Removed Instructions

Gracefully removed from UI
Warning if currently selected
Redirect to main view

Type Changes

Updated input validation
New enum options
Modified struct fields

State Preservation

During hot reload, Testship preserves:

Connected wallet
Selected network
Account suggestions list
Transaction history (up to reload)
Favorite accounts
UI preferences

Change Notifications

Stay informed with:

Toast notification on successful reload
Summary of changes detected
Warning for breaking changes
Error messages if reload fails

Configuration

Watch Options

Configure what triggers reloads:

[hot_reload]
enabled = true
watch_idl = true
watch_types = true
auto_reload_ui = true
preserve_state = true

Selective Reloading

Choose reload behavior:

Full Reload: Complete UI refresh
Partial Reload: Update only changed parts
Manual Reload: Prompt before reloading
Background Reload: Update without interruption

Debouncing

Prevent excessive reloads:

Wait for build completion
Batch multiple file changes
Configurable delay after changes

Advanced Features

Multi-Program Projects

For workspaces with multiple programs:

Track changes to all programs
Switch between program UIs
Maintain separate sessions
Hot reload each independently

Program Upgrades

When deploying updates:

Detect program address changes
Update IDL references
Maintain account mappings
Warn about breaking changes

Version History

Track your testing across versions:

See which program version was used
Compare behavior across versions
Rollback UI to previous program version
Useful for debugging regressions

Error Recovery

If hot reload fails:

Clear error message
Suggestion for manual refresh
Automatic retry
Rollback to last working state

Notifications

Change Types

Different notifications for different changes:

✅ Non-Breaking Changes

New instructions added
New optional parameters
Documentation updates
Minimal notification

⚠️ Breaking Changes

Removed instructions
Changed parameter types
Modified account structure
Prominent warning

❌ Errors

IDL parse failure
Invalid program changes
Build errors
Action required

Notification Settings

Customize notification behavior:

Toast messages
Desktop notifications
Sound alerts
Browser tab title updates

Use Cases

Rapid Prototyping

Iterate quickly on program design:

Add new instruction
Build
Test immediately
Refine based on results
Repeat

Bug Fixes

Fast debug cycle:

Identify issue in testing
Fix code
Build
Verify fix instantly
No setup needed

Feature Development

Smooth feature addition:

Implement new feature
Build
Test UI appears automatically
Validate with real transactions
Iterate rapidly

Learning & Exploration

Experiment with Solana concepts:

Modify program parameters
See effects immediately
Understand relationships
Build intuition faster

Performance

Hot reloading is optimized for speed:

IDL Parsing: < 100ms
UI Generation: < 500ms
State Migration: < 200ms
Total Reload Time: ~1 second

Network Impact

Minimal network usage:

Only IDL file monitored (KB-sized)
No unnecessary on-chain queries
Efficient file watching
Configurable polling interval

Troubleshooting

Hot Reload Not Working?

Check these common issues:

IDL not updating
- Ensure anchor build completes successfully
- Check target/idl/ directory exists
- Verify file permissions
UI doesn’t refresh
- Check if hot reload is enabled
- Look for error notifications
- Try manual refresh
State lost after reload
- Check preserve_state setting
- Some breaking changes can’t preserve state
- Session sharing maintains state

Manual Override

Force a reload:

Press Ctrl+R (or Cmd+R on Mac)
Click “Refresh UI” button
Restart Testship completely

Best Practices

During Development

Keep Testship running continuously
Build frequently to catch errors early
Review change notifications
Use version history for big changes

For Teams

Share sessions with hot reload enabled
Document program version with each test
Use session snapshots before breaking changes
Enable desktop notifications for collaborators

Coming Soon

Planned enhancements:

Hot reload for program upgrades
Visual diff of IDL changes
Automatic test re-execution
Change impact analysis
CI/CD integration

Next Steps

Explore the roadmap feature Export to Tests to see how Testship will integrate with your CI/CD pipeline.