Skip to content

The latest value, instead of the previous value, is provided in $effect teardown if the state is a $derived #16114

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom
Open
OptimisticSean opened this issue Jun 9, 2025 · 1 comment
Open

The latest value, instead of the previous value, is provided in $effect teardown if the state is a $derived #16114

OptimisticSean opened this issue Jun 9, 2025 · 1 comment
Labels
bug p0 stuff we should fix ASAP
Milestone
5.x

Comments

@OptimisticSean
Copy link

Describe the bug

Not sure if this is a bug or intended. According to this breaking change, if the state caused an $effect to rerun, Svelte should provide the previous value of the state in the teardown function. This work for $state currently, but not for $derived, though it does work if $derived is reassigned.

Reproduction

https://svelte.dev/playground/untitled?version=5.33.18#H4sIAAAAAAAACnWPy2rEMAxFf8WIgcl0woSuCm4SmC_oqqumizyU1tRVjKVkOgT_e3HS92MldHSPZM9A9TOChlsSIxY7SKE3Fhn03QxydnEWAaTvyaNzB57QSmRNzfgXbwcSJGHQkHPrjZOyokosimJVqA1LLZhc7q4_6II79GbCLuELXkZUyQb7HltJkp0qSjVHVEk7EA8WD3Z4SLaPRjFrtU0Vr5ZU4lFGT-qb9ENrzvjbC7GEXUV59vlsyptRZCA1UGtN-1TM617e70N57DrFebYmyv-z8X9XobyZ0J-8kXj7q-VK1mrmkGfurV36FUAKgi8CWvyI4T4FqY09GepA97VlDK_x94v_xwEAAA==

Logs



System Info


Svelte playground (5.33.18)
Chrome 137.0.7151.56


Severity


annoyance

      		
    

      
  





        



            
            

              
            

        

      


      
    








      

    



      

  
            


    







      

  
      



  

  @rChaoz





  


    

      

  

    

        
    
    

  


      
          
  
      
            Copy link

  

      
    

  


  

      

  
    Contributor


      

  


  

    

      

      
            rChaoz
  

      

      

      commented


        Jun 11, 2025


      
    


  





      


        


  
    

      
          
Strongly related to #16019

      		
    

  





        


            

            
            

              
            

        

      


      

            
  
  

    
  
    
    

  

  

  


    
















  
  

    

      

  





  




  
  

              

  
    Sign up for free
    to join this conversation on GitHub.
    Already have an account?
    Sign in to comment


  



  






  
                  




    

  


      
  

    Assignees
  



        

    No one assigned







      


  


  

    Labels
  



    

      

    bug

  

    p0

  stuff we should fix ASAP








      

  

    

        

    Projects
  


        




    None yet




  



      


  

    
  

    Milestone
  


      
    
  
    5.x
  





    
      
          


  

    

      
        

          
    

    Development
  




            
    
No branches or pull requests







      
    

  




      

    

  
      

  

    

      3 participants
    

    

        
          @rChaoz 
        
          @OptimisticSean 
        
          @elliott-with-the-longest-name-on-github