tests: Add test for diskCount. (#2717)

Fixes #2312

cmd/lock-rpc-server.go

@@ -115,7 +115,7 @@ func (l *lockServer) Lock(args *LockArgs, reply *bool) error {
 	}
 	_, *reply = l.lockMap[args.Name]
 	if !*reply { // No locks held on the given name, so claim write lock
-		l.lockMap[args.Name] = []lockRequesterInfo{lockRequesterInfo{writer: true, node: args.Node, rpcPath: args.RPCPath, uid: args.UID, timestamp: time.Now(), timeLastCheck: time.Now()}}
+		l.lockMap[args.Name] = []lockRequesterInfo{{writer: true, node: args.Node, rpcPath: args.RPCPath, uid: args.UID, timestamp: time.Now(), timeLastCheck: time.Now()}}
 	}
 	*reply = !*reply // Negate *reply to return true when lock is granted or false otherwise
 	return nil
@@ -152,7 +152,7 @@ func (l *lockServer) RLock(args *LockArgs, reply *bool) error {
 	var lri []lockRequesterInfo
 	lri, *reply = l.lockMap[args.Name]
 	if !*reply { // No locks held on the given name, so claim (first) read lock
-		l.lockMap[args.Name] = []lockRequesterInfo{lockRequesterInfo{writer: false, node: args.Node, rpcPath: args.RPCPath, uid: args.UID, timestamp: time.Now(), timeLastCheck: time.Now()}}
+		l.lockMap[args.Name] = []lockRequesterInfo{{writer: false, node: args.Node, rpcPath: args.RPCPath, uid: args.UID, timestamp: time.Now(), timeLastCheck: time.Now()}}
 		*reply = true
 	} else {
 		if *reply = !isWriteLock(lri); *reply { // Unless there is a write lock

cmd/xl-v1-utils_test.go

@@ -24,6 +24,31 @@ import (
 	"time"
 )
 
+// Tests caclculating disk count.
+func TestDiskCount(t *testing.T) {
+	testCases := []struct {
+		disks     []StorageAPI
+		diskCount int
+	}{
+		// Test case - 1
+		{
+			disks:     []StorageAPI{&posix{}, &posix{}, &posix{}, &posix{}},
+			diskCount: 4,
+		},
+		// Test case - 2
+		{
+			disks:     []StorageAPI{nil, &posix{}, &posix{}, &posix{}},
+			diskCount: 3,
+		},
+	}
+	for i, testCase := range testCases {
+		cdiskCount := diskCount(testCase.disks)
+		if cdiskCount != testCase.diskCount {
+			t.Errorf("Test %d: Expected %d, got %d", i+1, testCase.diskCount, cdiskCount)
+		}
+	}
+}
+
 // Test for reduceErrs, reduceErr reduces collection
 // of errors into a single maximal error with in the list.
 func TestReduceErrs(t *testing.T) {