Three panes, one clean merge

Merge Conflict Dojo

Jon once pointed out the obvious thing people somehow still ignore: if you are resolving a merge conflict, you need the common ancestor. This little dojo turns that instinct into a hands-on game. Study what changed on both sides, compose the best merge, and let the judge tell you whether you actually merged the intent, not just the text.

Scenarios
0/4
Current lesson
See the base
Merge style
Balanced
Warm-up

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Goal
Remoteteammate changes

                        

                        

                            
Ancestorcommon base

                            

                        

                        

                            
Localyour branch

                            

                        

                    

                


                

                    

                        
Read the room

                        

                    

                    

                        
When people go wrong

                        

                    

                


                

                    
Compose the merged file

                    
Try the obvious shortcuts if you want, but the best answer is often a careful combination. The live preview below shows what your final file will look like.

                    

                        

                            

                                
                                fast but risky
                            

                            

                        

                        

                            

                                
                                also risky
                            

                            

                        

                        

                            

                                
                                the grown-up answer
                            

                            
                        

                    

                    

                        
Live merged result

                        

                    

                    

                        
                        
                        
                    

                


                

                    
Judge

                    
The judge checks whether you preserved the intent from both branches.

                    
Pick a scenario, examine the ancestor, then build your merge.

                

            

        


        
Inspired by Jon's 2016 post urging people to resolve conflicts with a proper three-way diff. Correctly merging code is less about heroics and more about actually seeing what changed.