add unit tests and improve robustness

pkg/exchangerates/czech_national_bank_datasource.go

@@ -140,6 +140,11 @@ func (e *CzechNationalBankDataSource) parseExchangeRate(c core.Context, line str
 		return nil
 	}
 
+	if amount <= 0 {
+		log.Warnf(c, "[czech_national_bank_datasource.parseExchangeRate] amount is invalid, line is %s", line)
+		return nil
+	}
+
 	rate, err := utils.StringToFloat64(items[rateColumnIndex])
 
 	if err != nil {

pkg/exchangerates/czech_national_bank_datasource_test.go

@@ -73,6 +73,16 @@ func TestCzechNationalBankDataSource_OnlyHeaderAndTitle(t *testing.T) {
 	assert.NotEqual(t, nil, err)
 }
 
+func TestCzechNationalBankDataSource_MissingHeader(t *testing.T) {
+	dataSource := &CzechNationalBankDataSource{}
+	context := core.NewNullContext()
+
+	_, err := dataSource.Parse(context, []byte("Country|Currency|Amount|Code|Rate\n"+
+		"China|renminbi|1|CNY|3.379\n"+
+		"USA|dollar|1|USD|22.206\n"))
+	assert.NotEqual(t, nil, err)
+}
+
 func TestCzechNationalBankDataSource_TitleMissingCode(t *testing.T) {
 	dataSource := &CzechNationalBankDataSource{}
 	context := core.NewNullContext()
@@ -84,6 +94,17 @@ func TestCzechNationalBankDataSource_TitleMissingCode(t *testing.T) {
 	assert.NotEqual(t, nil, err)
 }
 
+func TestCzechNationalBankDataSource_TitleMissingAmount(t *testing.T) {
+	dataSource := &CzechNationalBankDataSource{}
+	context := core.NewNullContext()
+
+	_, err := dataSource.Parse(context, []byte("01 Apr 2021 #64\n"+
+		"Country|Currency|Code|Rate\n"+
+		"China|renminbi|CNY|3.379\n"+
+		"USA|dollar|USD|22.206\n"))
+	assert.NotEqual(t, nil, err)
+}
+
 func TestCzechNationalBankDataSource_TitleMissingRate(t *testing.T) {
 	dataSource := &CzechNationalBankDataSource{}
 	context := core.NewNullContext()
@@ -95,6 +116,17 @@ func TestCzechNationalBankDataSource_TitleMissingRate(t *testing.T) {
 	assert.NotEqual(t, nil, err)
 }
 
+func TestCzechNationalBankDataSource_MissingDataItem(t *testing.T) {
+	dataSource := &CzechNationalBankDataSource{}
+	context := core.NewNullContext()
+
+	actualLatestExchangeRateResponse, err := dataSource.Parse(context, []byte("01 Apr 2021 #64\n"+
+		"Country|Currency|Amount|Code|Rate\n"+
+		"USA|dollar|1|USD\n"))
+	assert.Equal(t, nil, err)
+	assert.Len(t, actualLatestExchangeRateResponse.ExchangeRates, 0)
+}
+
 func TestCzechNationalBankDataSource_InvalidCurrency(t *testing.T) {
 	dataSource := &CzechNationalBankDataSource{}
 	context := core.NewNullContext()
@@ -106,6 +138,23 @@ func TestCzechNationalBankDataSource_InvalidCurrency(t *testing.T) {
 	assert.Len(t, actualLatestExchangeRateResponse.ExchangeRates, 0)
 }
 
+func TestCzechNationalBankDataSource_InvalidAmount(t *testing.T) {
+	dataSource := &CzechNationalBankDataSource{}
+	context := core.NewNullContext()
+
+	actualLatestExchangeRateResponse, err := dataSource.Parse(context, []byte("01 Apr 2021 #64\n"+
+		"Country|Currency|Amount|Code|Rate\n"+
+		"USA|dollar|null|USD|22.206\n"))
+	assert.Equal(t, nil, err)
+	assert.Len(t, actualLatestExchangeRateResponse.ExchangeRates, 0)
+
+	actualLatestExchangeRateResponse, err = dataSource.Parse(context, []byte("01 Apr 2021 #64\n"+
+		"Country|Currency|Amount|Code|Rate\n"+
+		"USA|dollar|0|USD|22.206\n"))
+	assert.Equal(t, nil, err)
+	assert.Len(t, actualLatestExchangeRateResponse.ExchangeRates, 0)
+}
+
 func TestCzechNationalBankDataSource_EmptyRate(t *testing.T) {
 	dataSource := &CzechNationalBankDataSource{}
 	context := core.NewNullContext()
@@ -126,4 +175,10 @@ func TestCzechNationalBankDataSource_InvalidRate(t *testing.T) {
 		"USA|dollar|1|USD|null\n"))
 	assert.Equal(t, nil, err)
 	assert.Len(t, actualLatestExchangeRateResponse.ExchangeRates, 0)
+
+	actualLatestExchangeRateResponse, err = dataSource.Parse(context, []byte("01 Apr 2021 #64\n"+
+		"Country|Currency|Amount|Code|Rate\n"+
+		"USA|dollar|1|USD|0\n"))
+	assert.Equal(t, nil, err)
+	assert.Len(t, actualLatestExchangeRateResponse.ExchangeRates, 0)
 }