added test for revertPorts

pkg/proxy/iptables/proxier_test.go

@@ -374,4 +374,102 @@ func TestDeleteServiceConnections(t *testing.T) {
 	}
 }
 
+type fakeClosable struct {
+	closed bool
+}
+
+func (c *fakeClosable) Close() error {
+	c.closed = true
+	return nil
+}
+
+func TestRevertPorts(t *testing.T) {
+	testCases := []struct {
+		replacementPorts []localPort
+		existingPorts    []localPort
+		expectToBeClose  []bool
+	}{
+		{
+			replacementPorts: []localPort{
+				{port: 5001},
+				{port: 5002},
+				{port: 5003},
+			},
+			existingPorts:   []localPort{},
+			expectToBeClose: []bool{true, true, true},
+		},
+		{
+			replacementPorts: []localPort{},
+			existingPorts: []localPort{
+				{port: 5001},
+				{port: 5002},
+				{port: 5003},
+			},
+			expectToBeClose: []bool{},
+		},
+		{
+			replacementPorts: []localPort{
+				{port: 5001},
+				{port: 5002},
+				{port: 5003},
+			},
+			existingPorts: []localPort{
+				{port: 5001},
+				{port: 5002},
+				{port: 5003},
+			},
+			expectToBeClose: []bool{false, false, false},
+		},
+		{
+			replacementPorts: []localPort{
+				{port: 5001},
+				{port: 5002},
+				{port: 5003},
+			},
+			existingPorts: []localPort{
+				{port: 5001},
+				{port: 5003},
+			},
+			expectToBeClose: []bool{false, true, false},
+		},
+		{
+			replacementPorts: []localPort{
+				{port: 5001},
+				{port: 5002},
+				{port: 5003},
+			},
+			existingPorts: []localPort{
+				{port: 5001},
+				{port: 5002},
+				{port: 5003},
+				{port: 5004},
+			},
+			expectToBeClose: []bool{false, false, false},
+		},
+	}
+
+	for i, tc := range testCases {
+		replacementPortsMap := make(map[localPort]closeable)
+		for _, lp := range tc.replacementPorts {
+			replacementPortsMap[lp] = &fakeClosable{}
+		}
+		existingPortsMap := make(map[localPort]closeable)
+		for _, lp := range tc.existingPorts {
+			existingPortsMap[lp] = &fakeClosable{}
+		}
+		revertPorts(replacementPortsMap, existingPortsMap)
+		for j, expectation := range tc.expectToBeClose {
+			if replacementPortsMap[tc.replacementPorts[j]].(*fakeClosable).closed != expectation {
+				t.Errorf("Expect replacement localport %v to be %v in test case %v", tc.replacementPorts[j], expectation, i)
+			}
+		}
+		for _, lp := range tc.existingPorts {
+			if existingPortsMap[lp].(*fakeClosable).closed == true {
+				t.Errorf("Expect existing localport %v to be false in test case %v", lp, i)
+			}
+		}
+	}
+
+}
+
 // TODO(thockin): add a test for syncProxyRules() or break it down further and test the pieces.