question: Why Trainer resume_from_checkpoint only resume when fit.
context: I want to test again with ckpt. However I found Trainer resume_from_checkpoint only work for fit. Is there any particular reason for this?
  
    
      
        pytorch-lightning/pytorch_lightning/trainer/trainer.py
      
      
          Lines 840 to 841
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        f3442db
      
    
    
      
  
          
            
             if self.state.fn == TrainerFn.FITTING: 
          
  
          
            
                 self.checkpoint_connector.resume_start() 
          
      
    
  
  
  In [1]: from pytorch_lightning import seed_everything, Trainer
  
  In [2]: from src import MMTSMatcher, WDCDataModule
  
  In [3]: trainer = Trainer(resume_from_checkpoint="tests/mmtsmatcher_wdcdatamodule/shoes_small_false_32_0808-182020/checkpoints/epoch=05-valid_f1=81.22%.ckpt", gpus=[4])
  GPU available: True, used: True
  TPU available: False, using: 0 TPU cores
  IPU available: False, using: 0 IPUs
  
  In [4]: trainer
  Out[4]: <pytorch_lightning.trainer.trainer.Trainer at 0x7f2345178fa0>
  
  In [5]: model = MMTSMatcher(model_name="bert-base-uncased")
  
  In [6]: data = WDCDataModule(training_size="small", cate="shoes")
  
  In [7]: data
  Out[7]: <src.datamodules.wdcdatamodule.WDCDataModule at 0x7f22ccd258e0>
  
  In [10]: trainer.test(model, data)
answer: Dear @tshu-w,
  The resume_start will reload all states which might not be required for testing. We are currently refactoring this part of the code.
  Best,
  T.C