Move Changeset to use a generic type for the config, to avoid a bunch of boilerplate casting.

deployment/ccip/changeset/home_chain.go

@@ -13,14 +13,11 @@ import (
 	"github.com/smartcontractkit/chainlink/v2/core/gethwrappers/keystone/generated/capabilities_registry"
 )
 
-var _ deployment.ChangeSet = DeployHomeChain
+var _ deployment.ChangeSet[DeployHomeChainConfig] = DeployHomeChain
 
 // DeployHomeChain is a separate changeset because it is a standalone deployment performed once in home chain for the entire CCIP deployment.
-func DeployHomeChain(env deployment.Environment, config interface{}) (deployment.ChangesetOutput, error) {
-	cfg, ok := config.(DeployHomeChainConfig)
-	if !ok {
-		return deployment.ChangesetOutput{}, deployment.ErrInvalidConfig
-	}
+func DeployHomeChain(env deployment.Environment, cfg DeployHomeChainConfig) (deployment.ChangesetOutput, error) {
+
 	err := cfg.Validate()
 	if err != nil {
 		return deployment.ChangesetOutput{}, errors.Wrapf(deployment.ErrInvalidConfig, "%v", err)

deployment/ccip/changeset/initial_deploy.go

@@ -8,13 +8,9 @@ import (
 	ccipdeployment "github.com/smartcontractkit/chainlink/deployment/ccip"
 )
 
-var _ deployment.ChangeSet = InitialDeploy
+var _ deployment.ChangeSet[ccipdeployment.DeployCCIPContractConfig] = InitialDeploy
 
-func InitialDeploy(env deployment.Environment, config interface{}) (deployment.ChangesetOutput, error) {
-	c, ok := config.(ccipdeployment.DeployCCIPContractConfig)
-	if !ok {
-		return deployment.ChangesetOutput{}, deployment.ErrInvalidConfig
-	}
+func InitialDeploy(env deployment.Environment, c ccipdeployment.DeployCCIPContractConfig) (deployment.ChangesetOutput, error) {
 	newAddresses := deployment.NewMemoryAddressBook()
 	err := ccipdeployment.DeployCCIPContracts(env, newAddresses, c)
 	if err != nil {

deployment/changeset.go

@@ -18,7 +18,7 @@ var (
 // Its recommended that changesets operate on a small number of chains (e.g. 1-3)
 // to reduce the risk of partial failures.
 // If the configuration is unexpected type or format, the changeset should return ErrInvalidConfig.
-type ChangeSet func(e Environment, config interface{}) (ChangesetOutput, error)
+type ChangeSet[C any] func(e Environment, config C) (ChangesetOutput, error)
 
 // ChangesetOutput is the output of a Changeset function.
 // Think of it like a state transition output.

deployment/keystone/changeset/append_node_capbilities.go

@@ -8,19 +8,14 @@ import (
 	"github.com/smartcontractkit/chainlink/deployment/keystone/changeset/internal"
 )
 
-var _ deployment.ChangeSet = AppendNodeCapabilities
+var _ deployment.ChangeSet[*AppendNodeCapabilitiesRequest] = AppendNodeCapabilities
 
 // AppendNodeCapabilitiesRequest is a request to add capabilities to the existing capabilities of nodes in the registry
 type AppendNodeCapabilitiesRequest = MutateNodeCapabilitiesRequest
 
 // AppendNodeCapabilities adds any new capabilities to the registry, merges the new capabilities with the existing capabilities
 // of the node, and updates the nodes in the registry host the union of the new and existing capabilities.
-func AppendNodeCapabilities(env deployment.Environment, config any) (deployment.ChangesetOutput, error) {
-	req, ok := config.(*AppendNodeCapabilitiesRequest)
-	if !ok {
-		return deployment.ChangesetOutput{}, fmt.Errorf("invalid config type")
-	}
-
+func AppendNodeCapabilities(env deployment.Environment, req *AppendNodeCapabilitiesRequest) (deployment.ChangesetOutput, error) {
 	cfg, err := req.convert(env)
 	if err != nil {
 		return deployment.ChangesetOutput{}, err

deployment/keystone/changeset/deploy_forwarder.go

@@ -7,13 +7,9 @@ import (
 	kslib "github.com/smartcontractkit/chainlink/deployment/keystone"
 )
 
-var _ deployment.ChangeSet = DeployForwarder
+var _ deployment.ChangeSet[uint64] = DeployForwarder
 
-func DeployForwarder(env deployment.Environment, config interface{}) (deployment.ChangesetOutput, error) {
-	registryChainSel, ok := config.(uint64)
-	if !ok {
-		return deployment.ChangesetOutput{}, deployment.ErrInvalidConfig
-	}
+func DeployForwarder(env deployment.Environment, registryChainSel uint64) (deployment.ChangesetOutput, error) {
 	lggr := env.Logger
 	// expect OCR3 to be deployed & capabilities registry
 	regAddrs, err := env.ExistingAddresses.AddressesForChain(registryChainSel)

deployment/keystone/changeset/update_don.go

@@ -8,7 +8,7 @@ import (
 	kcr "github.com/smartcontractkit/chainlink/v2/core/gethwrappers/keystone/generated/capabilities_registry"
 )
 
-var _ deployment.ChangeSet = UpdateDon
+var _ deployment.ChangeSet[UpdateDonRequest] = UpdateDon
 
 // CapabilityConfig is a struct that holds a capability and its configuration
 type CapabilityConfig = internal.CapabilityConfig
@@ -22,9 +22,8 @@ type UpdateDonResponse struct {
 // UpdateDon updates the capabilities of a Don
 // This a complex action in practice that involves registering missing capabilities, adding the nodes, and updating
 // the capabilities of the DON
-func UpdateDon(env deployment.Environment, cfg any) (deployment.ChangesetOutput, error) {
-	req := cfg.(*UpdateDonRequest)
-	_, err := internal.UpdateDon(env.Logger, req)
+func UpdateDon(env deployment.Environment, req UpdateDonRequest) (deployment.ChangesetOutput, error) {
+	_, err := internal.UpdateDon(env.Logger, &req)
 	if err != nil {
 		return deployment.ChangesetOutput{}, fmt.Errorf("failed to update don: %w", err)
 	}

deployment/keystone/changeset/update_node_capabilities.go

@@ -5,6 +5,7 @@ import (
 	"fmt"
 
 	chainsel "github.com/smartcontractkit/chain-selectors"
+
 	"github.com/smartcontractkit/chainlink/deployment"
 	"github.com/smartcontractkit/chainlink/deployment/environment/clo/models"
 	kslib "github.com/smartcontractkit/chainlink/deployment/keystone"
@@ -14,7 +15,7 @@ import (
 	"github.com/smartcontractkit/chainlink/v2/core/services/keystore/keys/p2pkey"
 )
 
-var _ deployment.ChangeSet = UpdateNodeCapabilities
+var _ deployment.ChangeSet[MutateNodeCapabilitiesRequest] = UpdateNodeCapabilities
 
 type P2PSignerEnc = internal.P2PSignerEnc
 
@@ -84,11 +85,7 @@ func (req *MutateNodeCapabilitiesRequest) updateNodeCapabilitiesImplRequest(e de
 }
 
 // UpdateNodeCapabilities updates the capabilities of nodes in the registry
-func UpdateNodeCapabilities(env deployment.Environment, config any) (deployment.ChangesetOutput, error) {
-	req, ok := config.(*MutateNodeCapabilitiesRequest)
-	if !ok {
-		return deployment.ChangesetOutput{}, fmt.Errorf("invalid config type. want %T, got %T", &MutateNodeCapabilitiesRequest{}, config)
-	}
+func UpdateNodeCapabilities(env deployment.Environment, req MutateNodeCapabilitiesRequest) (deployment.ChangesetOutput, error) {
 	c, err := req.updateNodeCapabilitiesImplRequest(env)
 	if err != nil {
 		return deployment.ChangesetOutput{}, fmt.Errorf("failed to convert request: %w", err)