validation: bootstrap governance validator (#492)

validation/validators/governance.go

@@ -14,9 +14,68 @@
 
 package validators
 
+import (
+	"context"
+
+	"github.com/pkg/errors"
+	"github.com/stratumn/go-chainscript"
+	"github.com/stratumn/go-core/store"
+)
+
 const (
 	// GovernanceProcess is the name of the process containing validation rules
 	// in a decentralized network.
 	// Special rules apply to segments inside this process.
 	GovernanceProcess = "_governance"
 )
+
+// GovernanceRulesValidator validates the evolution of custom rules in a p2p
+// decentralized network.
+// The governance process will contain one map per business process. This map
+// will be responsible for updating the custom validation rules that apply to
+// the process' segments.
+// A governance process map should have the following structure:
+//
+// ,------------,                                         ,--------------,                                            ,----------------,
+// |   accept   | <====================================== |    accept    | <========================================= |     accept     |
+// | (rules v1) | <-.                                     |  (rules v2)  | <-.                                        |   (rules v3)   |
+// `------------'   |    ,----------,      ,---------,    `--------------'   |                                        `----------------'
+//                  |`-- |  update  |      |  vote   |           |           |                        ,---------,            |  |
+//                  |    | rules v2 | <=== | (alice) | <---------'           |   ,-------------,      |  vote   |            |  |
+//                  |    `----------'      `---------'                       |   |             | <=== | (alice) | <----------'  |
+//                  |    ,----------,                                        |   |   update    |      `---------'               |
+//                   `-- |  update  |                                         `--|  rules v3   |      ,---------,               |
+//                       | rules v3 | ---- X                                     |             | <=== |  vote   |               |
+//                       `----------'                                            `-------------'      |  (bob)  | <-------------'
+//                                                                                                    `---------'
+//
+// where:
+// <=== represents a parent relationship
+// <--- represents a reference
+//
+// Each accept link should also reference the latest link in the participants
+// map and check votes against these network participants.
+type GovernanceRulesValidator struct{}
+
+// NewGovernanceRulesValidator creates a validator for custom validation rules
+// updates.
+func NewGovernanceRulesValidator() Validator {
+	return &GovernanceRulesValidator{}
+}
+
+// Validate an update to a process' validation rules.
+func (v *GovernanceRulesValidator) Validate(context.Context, store.SegmentReader, *chainscript.Link) error {
+	return errors.New("not implemented")
+}
+
+// ShouldValidate returns true if the segment is a process governance segment.
+func (v *GovernanceRulesValidator) ShouldValidate(l *chainscript.Link) bool {
+	return l.Meta.Process.Name == GovernanceProcess &&
+		l.Meta.MapId != ParticipantsMap
+}
+
+// Hash returns an empty hash since the validator doesn't have any
+// configuration (it works the same for every decentralized network).
+func (v *GovernanceRulesValidator) Hash() ([]byte, error) {
+	return nil, nil
+}

validation/validators/governance_test.go

@@ -0,0 +1,59 @@
+// Copyright 2016-2018 Stratumn SAS. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package validators_test
+
+import (
+	"testing"
+
+	"github.com/stratumn/go-chainscript/chainscripttest"
+	"github.com/stratumn/go-core/validation/validators"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestGovernanceRulesValidator(t *testing.T) {
+	v := validators.NewGovernanceRulesValidator()
+
+	t.Run("ShouldValidate()", func(t *testing.T) {
+		t.Run("returns false for participant governance", func(t *testing.T) {
+			l := chainscripttest.NewLinkBuilder(t).
+				WithProcess(validators.GovernanceProcess).
+				WithMapID(validators.ParticipantsMap).
+				Build()
+			assert.False(t, v.ShouldValidate(l))
+		})
+
+		t.Run("returns false for non-governance links", func(t *testing.T) {
+			l := chainscripttest.NewLinkBuilder(t).
+				WithProcess("test_process").
+				Build()
+			assert.False(t, v.ShouldValidate(l))
+		})
+
+		t.Run("returns true for governance link", func(t *testing.T) {
+			l := chainscripttest.NewLinkBuilder(t).
+				WithProcess(validators.GovernanceProcess).
+				WithMapID("test_process").
+				Build()
+			assert.True(t, v.ShouldValidate(l))
+		})
+	})
+
+	t.Run("Hash()", func(t *testing.T) {
+		h, err := v.Hash()
+		require.NoError(t, err)
+		assert.Nil(t, h)
+	})
+}