add test for return single instance id

ec2id_test.go

@@ -74,6 +74,33 @@ func TestEc2id(t *testing.T) {
 		}, nil).
 		AnyTimes()
 
+	mockClient.EXPECT().
+		DescribeInstances(context.TODO(), &ec2.DescribeInstancesInput{
+			Filters: []types.Filter{
+				{
+					Name: aws.String("tag:Name"),
+					Values: []string{"test"},
+				},
+				{
+					Name: aws.String("instance-state-name"),
+					Values: []string{"running"},
+				},
+			},
+		}).
+		Return(&ec2.DescribeInstancesOutput{
+			Reservations: []types.Reservation {
+				{
+					Instances: []types.Instance {
+						{
+							InstanceId: aws.String("i-00000000000abcdef"),
+							LaunchTime: aws.Time(time.Date(2023, 1, 4, 12, 0, 0, 0, time.UTC)),
+						},
+					},
+				},
+			},
+		}, nil).
+		AnyTimes()
+
 	cases := []struct {
 		name string
 		client EC2DescribeInstancesAPI
@@ -98,6 +125,14 @@ func TestEc2id(t *testing.T) {
 			wantErr: false,
 			expectErr: "",
 		},
+		{
+			name: "return instance-id",
+			client: mockClient,
+			instanceName: "test",
+			expect: "i-00000000000abcdef",
+			wantErr: false,
+			expectErr: "",
+		},
 	}
 
 	for _, tt := range cases {