chore: replaced configurationError with direct fmt.Errorf

Since configurationError only added a prefix.

cmd/protoc-gen-gorums/dev/mgr.go

@@ -37,7 +37,7 @@ func NewManager(opts ...gorums.ManagerOption) (mgr *Manager) {
 // using the And, WithNewNodes, Except, and WithoutNodes methods.
 func (m *Manager) NewConfiguration(opts ...gorums.ConfigOption) (c *Configuration, err error) {
 	if len(opts) < 1 || len(opts) > 2 {
-		return nil, fmt.Errorf("wrong number of options: %d", len(opts))
+		return nil, fmt.Errorf("config: wrong number of options: %d", len(opts))
 	}
 	c = &Configuration{}
 	for _, opt := range opts {
@@ -51,13 +51,13 @@ func (m *Manager) NewConfiguration(opts ...gorums.ConfigOption) (c *Configuratio
 			// Must be last since v may match QuorumSpec if it is interface{}
 			c.qspec = v
 		default:
-			return nil, fmt.Errorf("unknown option type: %v", v)
+			return nil, fmt.Errorf("config: unknown option type: %v", v)
 		}
 	}
 	// return an error if the QuorumSpec interface is not empty and no implementation was provided.
 	var test interface{} = struct{}{}
 	if _, empty := test.(QuorumSpec); !empty && c.qspec == nil {
-		return nil, fmt.Errorf("missing required QuorumSpec")
+		return nil, fmt.Errorf("config: missing required QuorumSpec")
 	}
 	return c, nil
 }

config.go

@@ -1,5 +1,7 @@
 package gorums
 
+import "fmt"
+
 // RawConfiguration represents a static set of nodes on which quorum calls may be invoked.
 //
 // NOTE: mutating the configuration is not supported.
@@ -14,7 +16,7 @@ type RawConfiguration []*RawNode
 // using the And, WithNewNodes, Except, and WithoutNodes methods.
 func NewRawConfiguration(mgr *RawManager, opt NodeListOption) (nodes RawConfiguration, err error) {
 	if opt == nil {
-		return nil, configurationError("missing required node list")
+		return nil, fmt.Errorf("config: missing required node list")
 	}
 	return opt.newConfig(mgr)
 }

config_opts.go

@@ -1,6 +1,8 @@
 package gorums
 
-import "fmt"
+import (
+	"fmt"
+)
 
 // ConfigOption is a marker interface for options to NewConfiguration.
 type ConfigOption interface{}
@@ -17,7 +19,7 @@ type nodeIDMap struct {
 
 func (o nodeIDMap) newConfig(mgr *RawManager) (nodes RawConfiguration, err error) {
 	if len(o.idMap) == 0 {
-		return nil, configurationError("missing required node map")
+		return nil, fmt.Errorf("config: missing required node map")
 	}
 	nodes = make(RawConfiguration, 0, len(o.idMap))
 	for naddr, id := range o.idMap {
@@ -51,7 +53,7 @@ type nodeList struct {
 
 func (o nodeList) newConfig(mgr *RawManager) (nodes RawConfiguration, err error) {
 	if len(o.addrsList) == 0 {
-		return nil, configurationError("missing required node addresses")
+		return nil, fmt.Errorf("config: missing required node addresses")
 	}
 	nodes = make(RawConfiguration, 0, len(o.addrsList))
 	for _, naddr := range o.addrsList {
@@ -86,14 +88,14 @@ type nodeIDs struct {
 
 func (o nodeIDs) newConfig(mgr *RawManager) (nodes RawConfiguration, err error) {
 	if len(o.nodeIDs) == 0 {
-		return nil, configurationError("missing required node IDs")
+		return nil, fmt.Errorf("config: missing required node IDs")
 	}
 	nodes = make(RawConfiguration, 0, len(o.nodeIDs))
 	for _, id := range o.nodeIDs {
 		node, found := mgr.Node(id)
 		if !found {
 			// Node IDs must have been registered previously
-			return nil, configurationError(fmt.Sprintf("node %d not found", id))
+			return nil, fmt.Errorf("config: node %d not found", id)
 		}
 		nodes = append(nodes, node)
 	}

errors.go

@@ -5,11 +5,6 @@ import (
 	"fmt"
 )
 
-// configurationError reports that a Configuration could not be created.
-func configurationError(desc string) error {
-	return fmt.Errorf("configuration: %s", desc)
-}
-
 // A QuorumCallError is used to report that a quorum call failed.
 type QuorumCallError struct {
 	Reason     string

mgr.go

@@ -113,7 +113,7 @@ func (m *RawManager) Size() (nodes int) {
 func (m *RawManager) AddNode(node *RawNode) error {
 	if _, found := m.Node(node.ID()); found {
 		// Node IDs must be unique
-		return configurationError(fmt.Sprintf("node %d (%s) already exists", node.ID(), node.Address()))
+		return fmt.Errorf("config: node %d (%s) already exists", node.ID(), node.Address())
 	}
 	if m.logger != nil {
 		m.logger.Printf("Connecting to %s with id %d\n", node, node.id)

mgr_test.go

@@ -41,10 +41,10 @@ func TestManagerAddNode(t *testing.T) {
 		id   uint32
 		err  string
 	}{
-		{"127.0.1.1:1234", 1, "configuration: node 1 (127.0.1.1:1234) already exists"},
+		{"127.0.1.1:1234", 1, "config: node 1 (127.0.1.1:1234) already exists"},
 		{"127.0.1.1:1234", 5, ""},
-		{"127.0.1.1:1234", 6, ""}, // TODO(meling) does it make sense to allow same addr:port for different IDs?
-		{"127.0.1.1:1234", 2, "configuration: node 2 (127.0.1.1:1234) already exists"},
+		{"127.0.1.1:1234", 6, ""}, // The same addr:port can have different IDs
+		{"127.0.1.1:1234", 2, "config: node 2 (127.0.1.1:1234) already exists"},
 	}
 	for _, test := range tests {
 		node, err := gorums.NewRawNodeWithID(test.addr, test.id)