2019 DevDay Speed Up iOS Development With LLDB Code Injection and Framework Live Preview > ChienJu Lin > LINE Taiwan Engineering 7 iOS Developer

General Development Flow Product Verify Dev Spec Build

Pain Point - Long Build Time Product Dev Spec Build Verify

Reduce Number of Times
 To Rebuild Whole App

Build only the module that currently working on Less Compile Source Count Only Build the Framework Less Build Time

> Not embedded/linked by others Clean refactoring might need lots of works Tips for Existing Projects Apply Dummy Framework First Easier To Apply, Refactor Afterwards

How To Verify VIEW in Framework?

> No need many scrolls and clicks > Preview with different language / device size Interactive Fast Access Preview Under Different Environment SwiftUI / Playground Live Preview > Preview in different view state

How To Verify LOGIC in Framework?

Test Driven Development in Playground To build faster at every iteration Write Failing Test Make It Pass Refactor Unit Tests / TDD are best to verify logic > Unit Test the framework in playground for interactive environment > Move to test target for CI after completion

How To Speed Up Whole App Verification?

LLDB Code Injection Modify control flow without rebuild Inject new code using LLDB Command

LLDB Code Injection - Example Goal: Inject new view model to asynchronously download

LLDB Code Injection - Example 1. Insert breakpoint, enter multi-line expression mode

LLDB Code Injection - Example 2. Inject new view model code

LLDB Code Injection - Example 3. Execute the injected function

LLDB Code Injection - Example 4. Wait the async task to complete. Retrigger the breakpoint, check result & Done.

Framework Code Injection Preview Summary

Reduce Number of Times
 To Rebuild Whole App

Thank You