github.com/onflow/flow-go@v0.35.7-crescendo-preview.23-atree-inlining/utils/debug/README.md (about)

     1  
     2  
     3  ## Remote Debugger 
     4  
     5  Remote debugger provides utils needed to run transactions and scripts against live network data. It uses GRPC endpoints on an execution nodes to fetch registers and block info when running a transaction. This is mostly provided for debugging purpose and should not be used for production level operations. 
     6  If you use the caching method you can run the transaction once and use the cached values to run transaction in debugging mode. 
     7  
     8  ### sample code 
     9  
    10  ```GO
    11  package debug_test
    12  
    13  import (
    14  	"fmt"
    15  	"os"
    16  	"testing"
    17  
    18  	"github.com/rs/zerolog"
    19  	"github.com/stretchr/testify/require"
    20  
    21  	"github.com/onflow/flow-go/model/flow"
    22  	"github.com/onflow/flow-go/utils/debug"
    23  )
    24  
    25  func TestDebugger_RunTransaction(t *testing.T) {
    26  
    27  	grpcAddress := "localhost:3600"
    28  	chain := flow.Emulator.Chain()
    29  	debugger := debug.NewRemoteDebugger(grpcAddress, chain, zerolog.New(os.Stdout).With().Logger())
    30  
    31  	const scriptTemplate = `
    32  	import FlowServiceAccount from 0x%s
    33  	transaction() {
    34  		prepare(signer: &Account) {
    35  			log(signer.balance)
    36  		}
    37  	  }
    38  	`
    39  
    40  	script := []byte(fmt.Sprintf(scriptTemplate, chain.ServiceAddress()))
    41  	txBody := flow.NewTransactionBody().
    42  		SetComputeLimit(9999).
    43  		SetScript([]byte(script)).
    44  		SetPayer(chain.ServiceAddress()).
    45  		SetProposalKey(chain.ServiceAddress(), 0, 0)
    46  	txBody.Authorizers = []flow.Address{chain.ServiceAddress()}
    47  
    48  	// Run at the latest blockID
    49  	txErr, err := debugger.RunTransaction(txBody)
    50  	require.NoError(t, txErr)
    51  	require.NoError(t, err)
    52  
    53  	// Run with blockID (use the file cache)
    54  	blockId, err := flow.HexStringToIdentifier("3a8281395e2c1aaa3b8643d148594b19e2acb477611a8e0cab8a55c46c40b563")
    55  	require.NoError(t, err)
    56  	txErr, err = debugger.RunTransactionAtBlockID(txBody, blockId, "")
    57  	require.NoError(t, txErr)
    58  	require.NoError(t, err)
    59  
    60  	testCacheFile := "test.cache"
    61  	defer os.Remove(testCacheFile)
    62  	// the first run would cache the results
    63  	txErr, err = debugger.RunTransactionAtBlockID(txBody, blockId, testCacheFile)
    64  	require.NoError(t, txErr)
    65  	require.NoError(t, err)
    66  
    67  	// second one should only use the cache
    68  	// make blockId invalid so if it endsup looking up by id it should fail
    69  	blockId = flow.Identifier{}
    70  	txErr, err = debugger.RunTransactionAtBlockID(txBody, blockId, testCacheFile)
    71  	require.NoError(t, txErr)
    72  	require.NoError(t, err)
    73  }
    74  
    75  
    76  ```