reduce resolution code duplication

explorer/types.go

@@ -209,20 +209,6 @@ type V2HostAnnouncement struct {
 	chain.V2HostAnnouncement
 }
 
-// V2FileContractResolutionType enumerates the types of file contract resolution.
-type V2FileContractResolutionType interface {
-	isV2FileContractResolution()
-}
-
-func (*V2FileContractFinalization) isV2FileContractResolution() {}
-func (*V2FileContractRenewal) isV2FileContractResolution()      {}
-func (*V2StorageProof) isV2FileContractResolution()             {}
-func (*V2FileContractExpiration) isV2FileContractResolution()   {}
-
-// A V2FileContractFinalization finalizes a contract, preventing further
-// revisions and immediately creating its valid outputs.
-type V2FileContractFinalization types.Signature
-
 // A V2FileContractRenewal renews a file contract.
 type V2FileContractRenewal struct {
 	FinalRevision  V2FileContract `json:"finalRevision"`
@@ -235,35 +221,13 @@ type V2FileContractRenewal struct {
 	HostSignature   types.Signature `json:"hostSignature"`
 }
 
-// A V2StorageProof asserts the presence of a randomly-selected leaf within the
-// Merkle tree of a V2FileContract's data.
-type V2StorageProof struct {
-	// Selecting the leaf requires a source of unpredictable entropy; we use the
-	// ID of the block at the contract's ProofHeight. The storage proof thus
-	// includes a proof that this ID is the correct ancestor.
-	//
-	// During validation, it is imperative to check that ProofIndex.Height
-	// matches the ProofHeight field of the contract's final revision;
-	// otherwise, the prover could use any ProofIndex, giving them control over
-	// the leaf index.
-	ProofIndex types.ChainIndexElement
-
-	// The leaf is always 64 bytes, extended with zeros if necessary.
-	Leaf  [64]byte
-	Proof []types.Hash256
-}
-
-// A V2FileContractExpiration resolves an expired contract. A contract is
-// considered expired when its proof window has elapsed. If the contract is not
-// storing any data, it will resolve as valid; otherwise, it resolves as missed.
-type V2FileContractExpiration struct{}
-
 // A V2FileContractResolution closes a v2 file contract's payment channel.
 // There are four resolution types: renewwal, storage proof, finalization,
 // and expiration.
 type V2FileContractResolution struct {
-	Parent     V2FileContract               `json:"parent"`
-	Resolution V2FileContractResolutionType `json:"resolution"`
+	Parent     V2FileContract `json:"parent"`
+	Type       string         `json:"string"`
+	Resolution any            `json:"resolution"`
 }
 
 // A V2Transaction is a V2 transaction that uses the wrapped types above.

internal/testutil/check.go

@@ -212,29 +212,35 @@ func CheckV2Transaction(t *testing.T, expectTxn types.V2Transaction, gotTxn expl
 				CheckV2FC(t, v.FinalRevision, gotV.FinalRevision)
 				CheckV2FC(t, v.NewContract, gotV.NewContract)
 
+				Equal(t, "type", "renewal", got.Type)
 				Equal(t, "renter rollover", v.RenterRollover, gotV.RenterRollover)
 				Equal(t, "host rollover", v.HostRollover, gotV.HostRollover)
 				Equal(t, "renter signature", v.RenterSignature, gotV.RenterSignature)
 				Equal(t, "host signature", v.HostSignature, gotV.HostSignature)
 			}
 		case *types.V2StorageProof:
-			if gotV, ok := got.Resolution.(*explorer.V2StorageProof); !ok {
+			if gotV, ok := got.Resolution.(*types.V2StorageProof); !ok {
 				t.Fatalf("expected V2StorageProof, got %v", reflect.TypeOf(got.Resolution))
 			} else {
+				Equal(t, "type", "storageProof", got.Type)
 				Equal(t, "proof index", v.ProofIndex, gotV.ProofIndex)
 				Equal(t, "leaf", v.Leaf, gotV.Leaf)
 				Equal(t, "proof", v.Proof, gotV.Proof)
 			}
 		case *types.V2FileContractFinalization:
-			if gotV, ok := got.Resolution.(*explorer.V2FileContractFinalization); !ok {
+			if gotV, ok := got.Resolution.(*types.V2FileContractFinalization); !ok {
 				t.Fatalf("expected V2FileContractFinalization, got %v", reflect.TypeOf(got.Resolution))
 			} else {
+				Equal(t, "type", "finalization", got.Type)
 				Equal(t, "finalization signature", types.Signature(*v), types.Signature(*gotV))
 			}
 		case *types.V2FileContractExpiration:
-			if _, ok := got.Resolution.(*explorer.V2FileContractExpiration); !ok {
+			Equal(t, "type", "expiration", got.Type)
+			if _, ok := got.Resolution.(*types.V2FileContractExpiration); !ok {
 				t.Fatalf("expected V2FileContractExpiration, got %v", reflect.TypeOf(got.Resolution))
 			}
+		default:
+			t.Fatalf("invalid resolution type: %v", reflect.TypeOf(got.Resolution))
 		}
 	}
 

persist/sqlite/v2transactions.go

@@ -497,7 +497,9 @@ WHERE fc.id = ?`)
 					return fmt.Errorf("failed to scan file contract: %w", err)
 				}
 
-				var res explorer.V2FileContractResolutionType
+				fcr := explorer.V2FileContractResolution{
+					Parent: parent,
+				}
 				switch resolutionType {
 				case 0: // V2FileContractRenewal
 					renewal := &explorer.V2FileContractRenewal{
@@ -518,25 +520,28 @@ WHERE fc.id = ?`)
 							return fmt.Errorf("failed to scan new contract: %w", err)
 						}
 					}
-					res = renewal
+
+					fcr.Type = "renewal"
+					fcr.Resolution = renewal
 				case 1: // V2StorageProof
-					proof := &explorer.V2StorageProof{
+					proof := &types.V2StorageProof{
 						ProofIndex: storageProofProofIndex,
 						Proof:      storageProofProof,
 						Leaf:       [64]byte(storageProofLeaf),
 					}
-					res = proof
+
+					fcr.Type = "storageProof"
+					fcr.Resolution = proof
 				case 2: // V2FileContractFinalization
-					res = (*explorer.V2FileContractFinalization)(&finalizationSignature)
+					fcr.Type = "finalization"
+					fcr.Resolution = (*types.V2FileContractFinalization)(&finalizationSignature)
 				case 3: // V2FileContractExpiration
-					res = new(explorer.V2FileContractExpiration)
+					fcr.Type = "expiration"
+					fcr.Resolution = new(types.V2FileContractExpiration)
 				}
 
 				// Append the resolution to the transaction.
-				txns[i].FileContractResolutions = append(txns[i].FileContractResolutions, explorer.V2FileContractResolution{
-					Parent:     parent,
-					Resolution: res,
-				})
+				txns[i].FileContractResolutions = append(txns[i].FileContractResolutions, fcr)
 			}
 			return nil
 		}()