added select plan by id

store/postgres_test.go

@@ -47,6 +47,45 @@ func TestSelectPlans(t *testing.T) {
 	}
 }
 
+func TestSelectPlanByID(t *testing.T) {
+	assert := assert.New(t)
+
+	currentTime := time.Now()
+	idToUse := 1
+
+	str, mock := getDbMock(t)
+
+	rows := sqlmock.NewRows([]string{"plan_id", "plan_date"}).AddRow(idToUse, currentTime)
+	mock.ExpectQuery("^SELECT plan_id, plan_date FROM plans WHERE plan_id = \\$1$").WithArgs(idToUse).WillReturnRows(rows)
+
+	plan, err := str.SelectPlanByID(idToUse)
+	assert.Nil(err)
+	assert.EqualValues(idToUse, plan.PlanID)
+	assert.Equal(currentTime, plan.PlanDate)
+
+	if err := mock.ExpectationsWereMet(); err != nil {
+		t.Errorf("unfulfilled expectations: %s", err)
+	}
+}
+
+func TestErrPlanByID(t *testing.T) {
+	assert := assert.New(t)
+
+	idToUse := 1
+
+	str, mock := getDbMock(t)
+
+	mock.ExpectQuery("^SELECT plan_id, plan_date FROM plans WHERE plan_id = \\$1$").WithArgs(idToUse).WillReturnError(fmt.Errorf("example error"))
+
+	plan, err := str.SelectPlanByID(idToUse)
+	assert.NotNil(err)
+	assert.Nil(plan)
+
+	if err := mock.ExpectationsWereMet(); err != nil {
+		t.Errorf("unfulfilled expectations: %s", err)
+	}
+}
+
 func TestSelectActions(t *testing.T) {
 	// set up  test
 	assert := assert.New(t)