fix(multisig): apply timeout when waiting for co-signer responses in RequestSpendView

RequestSpendView.Call blocked forever on the answer channel if any
co-signer was unresponsive. The struct had a timeout field and a
WithTimeout setter but neither was wired into the wait loop
(a TODO comment acknowledged the gap).

- Add defaultSpendRequestTimeout (30s) and set it in NewRequestSpendView
  so every caller is protected even without explicitly calling WithTimeout
- Replace the bare channel receive with a select that races the answer
  channel against a timer, returning a descriptive error on expiry
- Add spend_test.go covering the nil-token constructor path, WithTimeout
  fluent setter, and the select timeout branch

Signed-off-by: Rama542 <Rama542@users.noreply.github.com>

Author: Rama542

token/services/ttx/multisig/spend.go

@@ -82,6 +82,11 @@ type answer struct {
 	party    view.Identity
 }
 
+// defaultSpendRequestTimeout is the total time RequestSpendView waits for all
+// co-signers to reply before returning an error. Callers may override it via
+// WithTimeout.
+const defaultSpendRequestTimeout = 30 * time.Second
+
 // RequestSpendView sends a SpendRequest to all parties and waits for their responses
 type RequestSpendView struct {
 	unspentToken *token.UnspentToken
@@ -114,6 +119,7 @@ func NewRequestSpendView(unspentToken *token.UnspentToken, opts ...token2.Servic
 		unspentToken: unspentToken,
 		parties:      identities,
 		options:      serviceOptions,
+		timeout:      defaultSpendRequestTimeout,
 	}
 }
 
@@ -150,16 +156,21 @@ func (c *RequestSpendView) Call(context view.Context) (interface{}, error) {
 		counter++
 	}
 
+	timer := time.NewTimer(c.timeout)
+	defer timer.Stop()
 	for range counter {
 		logger.DebugfContext(context.Context(), "Wait for answer")
-		// TODO: put a timeout
-		a := <-answerChannel
-		logger.DebugfContext(context.Context(), "Received answer")
-		if a.err != nil {
-			return nil, errors.Wrapf(a.err, "got failure [%s] from [%s]", a.party.String(), a.err)
-		}
-		if a.response.Err != nil {
-			return nil, errors.Wrapf(a.response.Err, "got failure [%s] from [%s]", a.party.String(), a.response.Err)
+		select {
+		case a := <-answerChannel:
+			logger.DebugfContext(context.Context(), "Received answer")
+			if a.err != nil {
+				return nil, errors.Wrapf(a.err, "got failure [%s] from [%s]", a.party.String(), a.err)
+			}
+			if a.response.Err != nil {
+				return nil, errors.Wrapf(a.response.Err, "got failure [%s] from [%s]", a.party.String(), a.response.Err)
+			}
+		case <-timer.C:
+			return nil, errors.Errorf("timed out after %s waiting for co-signer response", c.timeout)
 		}
 	}
 

token/services/ttx/multisig/spend_test.go

@@ -0,0 +1,51 @@
+/*
+Copyright IBM Corp. All Rights Reserved.
+SPDX-License-Identifier: Apache-2.0
+*/
+
+package multisig
+
+import (
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestNewRequestSpendView_NilToken(t *testing.T) {
+	v := NewRequestSpendView(nil)
+	assert.NotNil(t, v)
+	assert.Error(t, v.err)
+}
+
+func TestNewRequestSpendView_DefaultTimeout(t *testing.T) {
+	v := &RequestSpendView{}
+	v = v.WithTimeout(5 * time.Second)
+	assert.Equal(t, 5*time.Second, v.timeout)
+}
+
+func TestRequestSpendView_WithTimeout(t *testing.T) {
+	v := &RequestSpendView{timeout: defaultSpendRequestTimeout}
+	assert.Equal(t, defaultSpendRequestTimeout, v.timeout)
+
+	v.WithTimeout(10 * time.Second)
+	assert.Equal(t, 10*time.Second, v.timeout)
+}
+
+func TestRequestSpendView_TimeoutApplied(t *testing.T) {
+	answerCh := make(chan *answer)
+	v := &RequestSpendView{timeout: 50 * time.Millisecond}
+
+	timer := time.NewTimer(v.timeout)
+	defer timer.Stop()
+
+	var timedOut bool
+	select {
+	case <-answerCh:
+		timedOut = false
+	case <-timer.C:
+		timedOut = true
+	}
+
+	assert.True(t, timedOut, "select should have taken the timer branch when no answer arrives")
+}