runtime-sdk/modules/rofl: Add YAML serialization for ROFL fee policy

.golangci.yml

@@ -77,3 +77,4 @@ linters-settings:
           - github.com/shopspring/decimal
           - github.com/golang/snappy
           - github.com/stretchr/testify
+          - gopkg.in/yaml.v3

client-sdk/go/modules/rofl/policy.go

@@ -1,6 +1,10 @@
 package rofl
 
 import (
+	"fmt"
+
+	"gopkg.in/yaml.v3"
+
 	beacon "github.com/oasisprotocol/oasis-core/go/beacon/api"
 	"github.com/oasisprotocol/oasis-core/go/common/crypto/signature"
 	"github.com/oasisprotocol/oasis-core/go/common/sgx"
@@ -39,8 +43,31 @@ type AllowedEndorsement struct {
 type FeePolicy uint8
 
 const (
-	// FeePolicyAppPays is a fee policy where the application enclave pays the gas fees.
-	FeePolicyAppPays FeePolicy = 1
+	// FeePolicyInstancePays is a fee policy where the application enclave pays the gas fees.
+	FeePolicyInstancePays FeePolicy = 1
 	// FeePolicyEndorsingNodePays is a fee policy where the endorsing node pays the gas fees.
 	FeePolicyEndorsingNodePays FeePolicy = 2
 )
+
+// UnmarshalYAML implements yaml.Unmarshaler.
+func (fp *FeePolicy) UnmarshalYAML(value *yaml.Node) error {
+	switch value.ShortTag() {
+	case "!!str":
+		var feePolicyStr string
+		if err := value.Decode(&feePolicyStr); err != nil {
+			return err
+		}
+
+		switch feePolicyStr {
+		case "instance":
+			*fp = FeePolicyInstancePays
+		case "endorsing_node":
+			*fp = FeePolicyEndorsingNodePays
+		default:
+			return fmt.Errorf("unsupported fee policy: '%s'", feePolicyStr)
+		}
+		return nil
+	default:
+		return fmt.Errorf("unsupported fee policy type")
+	}
+}

client-sdk/go/modules/rofl/policy_test.go

@@ -0,0 +1,37 @@
+package rofl
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+	"gopkg.in/yaml.v3"
+)
+
+func TestPolicySerialization(t *testing.T) {
+	require := require.New(t)
+
+	tcs := []struct {
+		data     string
+		ok       bool
+		expected FeePolicy
+	}{
+		{"instance", true, FeePolicyInstancePays},
+		{"endorsing_node", true, FeePolicyEndorsingNodePays},
+		{"1", false, 0},
+		{"2", false, 0},
+		{"foo", false, 0},
+		{"3", false, 0},
+		{"{}", false, 0},
+	}
+
+	for _, tc := range tcs {
+		var dec FeePolicy
+		err := yaml.Unmarshal([]byte(tc.data), &dec)
+		if tc.ok {
+			require.NoError(err, "yaml.Unmarshal")
+			require.EqualValues(tc.expected, dec)
+		} else {
+			require.Error(err, "yaml.Unmarshal")
+		}
+	}
+}

runtime-sdk/src/modules/rofl/mod.rs

@@ -497,7 +497,7 @@ impl<Cfg: Config> module::FeeProxyHandler for Module<Cfg> {
         )?;
 
         match app_policy.fees {
-            FeePolicy::AppPays => {
+            FeePolicy::InstancePays => {
                 // Application needs to figure out a way to pay, defer to regular handler.
                 Ok(None)
             }

runtime-sdk/src/modules/rofl/policy.rs

@@ -47,7 +47,7 @@ pub enum AllowedEndorsement {
 #[repr(u8)]
 pub enum FeePolicy {
     /// Application enclave pays the gas fees.
-    AppPays = 1,
+    InstancePays = 1,
     /// Endorsing node pays the gas fees.
     #[default]
     EndorsingNodePays = 2,