refactor(scaler): compare error with errors.Is

CHANGELOG.md

@@ -73,6 +73,7 @@ New deprecation(s):
 ### Other
 
 - **RabbitMQ Scaler:** Move from `streadway/amqp` to `rabbitmq/amqp091-go` ([#4004](https://github.com/kedacore/keda/pull/4039))
+- **General:** Compare error with `errors.Is` ([#4004](https://github.com/kedacore/keda/pull/4004))
 
 ## v2.9.1
 

pkg/scalers/aws_common.go

@@ -1,6 +1,7 @@
 package scalers
 
 import (
+	"errors"
 	"fmt"
 
 	"github.com/aws/aws-sdk-go/aws"
@@ -9,6 +10,9 @@ import (
 	"github.com/aws/aws-sdk-go/aws/session"
 )
 
+// ErrAwsNoAccessKey is returned when awsAccessKeyID is missing.
+var ErrAwsNoAccessKey = errors.New("awsAccessKeyID not found")
+
 type awsAuthorizationMetadata struct {
 	awsRoleArn string
 
@@ -81,7 +85,7 @@ func getAwsAuthorization(authParams, metadata, resolvedEnv map[string]string) (a
 			}
 
 			if len(meta.awsAccessKeyID) == 0 {
-				return meta, fmt.Errorf("awsAccessKeyID not found")
+				return meta, ErrAwsNoAccessKey
 			}
 
 			if metadata["awsSecretAccessKeyFromEnv"] != "" {

pkg/scalers/aws_dynamodb_scaler.go

@@ -58,19 +58,48 @@ func NewAwsDynamoDBScaler(config *ScalerConfig) (Scaler, error) {
 	}, nil
 }
 
+var (
+	// ErrAwsDynamoNoTableName is returned when "tableName" is missing from the config.
+	ErrAwsDynamoNoTableName = errors.New("no tableName given")
+
+	// ErrAwsDynamoNoAwsRegion is returned when "awsRegion" is missing from the config.
+	ErrAwsDynamoNoAwsRegion = errors.New("no awsRegion given")
+
+	// ErrAwsDynamoNoKeyConditionExpression is returned when "keyConditionExpression" is missing from the config.
+	ErrAwsDynamoNoKeyConditionExpression = errors.New("no keyConditionExpression given")
+
+	// ErrAwsDynamoEmptyExpressionAttributeNames is returned when "expressionAttributeNames" is empty.
+	ErrAwsDynamoEmptyExpressionAttributeNames = errors.New("empty map")
+
+	// ErrAwsDynamoInvalidExpressionAttributeNames is returned when "expressionAttributeNames" is an invalid JSON.
+	ErrAwsDynamoInvalidExpressionAttributeNames = errors.New("invalid expressionAttributeNames")
+
+	// ErrAwsDynamoNoExpressionAttributeNames is returned when "expressionAttributeNames" is missing from the config.
+	ErrAwsDynamoNoExpressionAttributeNames = errors.New("no expressionAttributeNames given")
+
+	// ErrAwsDynamoInvalidExpressionAttributeValues is returned when "expressionAttributeNames" is missing an invalid JSON.
+	ErrAwsDynamoInvalidExpressionAttributeValues = errors.New("invalid expressionAttributeValues")
+
+	// ErrAwsDynamoNoExpressionAttributeValues is returned when "expressionAttributeValues" is missing from the config.
+	ErrAwsDynamoNoExpressionAttributeValues = errors.New("no expressionAttributeValues given")
+
+	// ErrAwsDynamoNoTargetValue is returned when "targetValue" is missing from the config.
+	ErrAwsDynamoNoTargetValue = errors.New("no targetValue given")
+)
+
 func parseAwsDynamoDBMetadata(config *ScalerConfig) (*awsDynamoDBMetadata, error) {
 	meta := awsDynamoDBMetadata{}
 
 	if val, ok := config.TriggerMetadata["tableName"]; ok && val != "" {
 		meta.tableName = val
 	} else {
-		return nil, fmt.Errorf("no tableName given")
+		return nil, ErrAwsDynamoNoTableName
 	}
 
 	if val, ok := config.TriggerMetadata["awsRegion"]; ok && val != "" {
 		meta.awsRegion = val
 	} else {
-		return nil, fmt.Errorf("no awsRegion given")
+		return nil, ErrAwsDynamoNoAwsRegion
 	}
 
 	if val, ok := config.TriggerMetadata["awsEndpoint"]; ok {
@@ -80,48 +109,48 @@ func parseAwsDynamoDBMetadata(config *ScalerConfig) (*awsDynamoDBMetadata, error
 	if val, ok := config.TriggerMetadata["keyConditionExpression"]; ok && val != "" {
 		meta.keyConditionExpression = val
 	} else {
-		return nil, fmt.Errorf("no keyConditionExpression given")
+		return nil, ErrAwsDynamoNoKeyConditionExpression
 	}
 
 	if val, ok := config.TriggerMetadata["expressionAttributeNames"]; ok && val != "" {
 		names, err := json2Map(val)
 
 		if err != nil {
-			return nil, fmt.Errorf("error parsing expressionAttributeNames: %s", err)
+			return nil, fmt.Errorf("error parsing expressionAttributeNames: %w", err)
 		}
 
 		meta.expressionAttributeNames = names
 	} else {
-		return nil, fmt.Errorf("no expressionAttributeNames given")
+		return nil, ErrAwsDynamoNoExpressionAttributeNames
 	}
 
 	if val, ok := config.TriggerMetadata["expressionAttributeValues"]; ok && val != "" {
 		values, err := json2DynamoMap(val)
 
 		if err != nil {
-			return nil, fmt.Errorf("error parsing expressionAttributeValues: %s", err)
+			return nil, fmt.Errorf("error parsing expressionAttributeValues: %w", err)
 		}
 
 		meta.expressionAttributeValues = values
 	} else {
-		return nil, fmt.Errorf("no expressionAttributeValues given")
+		return nil, ErrAwsDynamoNoExpressionAttributeValues
 	}
 
 	if val, ok := config.TriggerMetadata["targetValue"]; ok && val != "" {
 		n, err := strconv.ParseInt(val, 10, 64)
 		if err != nil {
-			return nil, fmt.Errorf("error parsing metadata targetValue")
+			return nil, fmt.Errorf("error parsing metadata targetValue: %w", err)
 		}
 
 		meta.targetValue = n
 	} else {
-		return nil, fmt.Errorf("no targetValue given")
+		return nil, ErrAwsDynamoNoTargetValue
 	}
 
 	if val, ok := config.TriggerMetadata["activationTargetValue"]; ok && val != "" {
 		n, err := strconv.ParseInt(val, 10, 64)
 		if err != nil {
-			return nil, fmt.Errorf("error parsing metadata targetValue")
+			return nil, fmt.Errorf("error parsing metadata activationTargetValue: %w", err)
 		}
 
 		meta.activationTargetValue = n
@@ -202,11 +231,11 @@ func (s *awsDynamoDBScaler) GetQueryMetrics() (float64, error) {
 func json2Map(js string) (m map[string]*string, err error) {
 	err = bson.UnmarshalExtJSON([]byte(js), true, &m)
 	if err != nil {
-		return nil, err
+		return nil, fmt.Errorf("%w: %v", ErrAwsDynamoInvalidExpressionAttributeNames, err)
 	}
 
 	if len(m) == 0 {
-		return nil, errors.New("empty map")
+		return nil, ErrAwsDynamoEmptyExpressionAttributeNames
 	}
 	return m, err
 }
@@ -216,7 +245,7 @@ func json2DynamoMap(js string) (m map[string]*dynamodb.AttributeValue, err error
 	err = json.Unmarshal([]byte(js), &m)
 
 	if err != nil {
-		return nil, err
+		return nil, fmt.Errorf("%w: %v", ErrAwsDynamoInvalidExpressionAttributeValues, err)
 	}
 	return m, err
 }

pkg/scalers/aws_dynamodb_scaler_test.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"errors"
 	"fmt"
+	"strconv"
 	"testing"
 
 	"github.com/aws/aws-sdk-go/service/dynamodb"
@@ -38,13 +39,13 @@ var dynamoTestCases = []parseDynamoDBMetadataTestData{
 		name:          "no tableName given",
 		metadata:      map[string]string{},
 		authParams:    map[string]string{},
-		expectedError: errors.New("no tableName given"),
+		expectedError: ErrAwsDynamoNoTableName,
 	},
 	{
 		name:          "no awsRegion given",
 		metadata:      map[string]string{"tableName": "test"},
 		authParams:    map[string]string{},
-		expectedError: errors.New("no awsRegion given"),
+		expectedError: ErrAwsDynamoNoAwsRegion,
 	},
 	{
 		name: "no keyConditionExpression given",
@@ -53,7 +54,7 @@ var dynamoTestCases = []parseDynamoDBMetadataTestData{
 			"awsRegion": "eu-west-1",
 		},
 		authParams:    map[string]string{},
-		expectedError: errors.New("no keyConditionExpression given"),
+		expectedError: ErrAwsDynamoNoKeyConditionExpression,
 	},
 	{
 		name: "no expressionAttributeNames given",
@@ -63,7 +64,7 @@ var dynamoTestCases = []parseDynamoDBMetadataTestData{
 			"keyConditionExpression": "#yr = :yyyy",
 		},
 		authParams:    map[string]string{},
-		expectedError: errors.New("no expressionAttributeNames given"),
+		expectedError: ErrAwsDynamoNoExpressionAttributeNames,
 	},
 	{
 		name: "no expressionAttributeValues given",
@@ -74,7 +75,7 @@ var dynamoTestCases = []parseDynamoDBMetadataTestData{
 			"expressionAttributeNames": "{ \"#yr\" : \"year\" }",
 		},
 		authParams:    map[string]string{},
-		expectedError: errors.New("no expressionAttributeValues given"),
+		expectedError: ErrAwsDynamoNoExpressionAttributeValues,
 	},
 	{
 		name: "no targetValue given",
@@ -86,7 +87,7 @@ var dynamoTestCases = []parseDynamoDBMetadataTestData{
 			"expressionAttributeValues": "{\":yyyy\": {\"N\": \"1994\"}}",
 		},
 		authParams:    map[string]string{},
-		expectedError: errors.New("no targetValue given"),
+		expectedError: ErrAwsDynamoNoTargetValue,
 	},
 	{
 		name: "invalid targetValue given",
@@ -99,7 +100,7 @@ var dynamoTestCases = []parseDynamoDBMetadataTestData{
 			"targetValue":               "no-valid",
 		},
 		authParams:    map[string]string{},
-		expectedError: errors.New("error parsing metadata targetValue"),
+		expectedError: strconv.ErrSyntax,
 	},
 	{
 		name: "invalid activationTargetValue given",
@@ -113,7 +114,7 @@ var dynamoTestCases = []parseDynamoDBMetadataTestData{
 			"activationTargetValue":     "no-valid",
 		},
 		authParams:    map[string]string{},
-		expectedError: errors.New("error parsing metadata targetValue"),
+		expectedError: strconv.ErrSyntax,
 	},
 	{
 		name: "malformed expressionAttributeNames",
@@ -126,7 +127,7 @@ var dynamoTestCases = []parseDynamoDBMetadataTestData{
 			"targetValue":               "3",
 		},
 		authParams:    map[string]string{},
-		expectedError: errors.New("error parsing expressionAttributeNames: invalid JSON input: missing colon after key \"malformed\""),
+		expectedError: ErrAwsDynamoInvalidExpressionAttributeNames,
 	},
 	{
 		name: "empty expressionAttributeNames",
@@ -139,7 +140,7 @@ var dynamoTestCases = []parseDynamoDBMetadataTestData{
 			"targetValue":               "3",
 		},
 		authParams:    map[string]string{},
-		expectedError: errors.New("error parsing expressionAttributeNames: empty map"),
+		expectedError: ErrAwsDynamoEmptyExpressionAttributeNames,
 	},
 	{
 		name: "malformed expressionAttributeValues",
@@ -152,7 +153,7 @@ var dynamoTestCases = []parseDynamoDBMetadataTestData{
 			"targetValue":               "3",
 		},
 		authParams:    map[string]string{},
-		expectedError: errors.New("error parsing expressionAttributeValues: json: cannot unmarshal number into Go struct field AttributeValue.N of type string"),
+		expectedError: ErrAwsDynamoInvalidExpressionAttributeValues,
 	},
 	{
 		name: "no aws given",
@@ -165,7 +166,7 @@ var dynamoTestCases = []parseDynamoDBMetadataTestData{
 			"targetValue":               "3",
 		},
 		authParams:    map[string]string{},
-		expectedError: errors.New("awsAccessKeyID not found"),
+		expectedError: ErrAwsNoAccessKey,
 	},
 	{
 		name: "authentication provided",
@@ -237,7 +238,7 @@ func TestParseDynamoMetadata(t *testing.T) {
 				ScalerIndex:     1,
 			})
 			if tc.expectedError != nil {
-				assert.Contains(t, err.Error(), tc.expectedError.Error())
+				assert.ErrorIs(t, err, tc.expectedError)
 			} else {
 				assert.NoError(t, err)
 				fmt.Println(tc.name)

pkg/scalers/azure/azure_blob_test.go

@@ -2,8 +2,9 @@ package azure
 
 import (
 	"context"
+	"encoding/base64"
+	"errors"
 	"net/http"
-	"strings"
 	"testing"
 
 	kedav1alpha1 "github.com/kedacore/keda/v2/apis/keda/v1alpha1"
@@ -22,7 +23,7 @@ func TestGetBlobLength(t *testing.T) {
 		t.Error("Expected error for empty connection string, but got nil")
 	}
 
-	if !strings.Contains(err.Error(), "parse storage connection string") {
+	if !errors.Is(err, ErrAzureConnectionStringKeyName) {
 		t.Error("Expected error to contain parsing error message, but got", err.Error())
 	}
 
@@ -37,7 +38,8 @@ func TestGetBlobLength(t *testing.T) {
 		t.Error("Expected error for empty connection string, but got nil")
 	}
 
-	if !strings.Contains(err.Error(), "illegal base64") {
+	var base64Error base64.CorruptInputError
+	if !errors.As(err, &base64Error) {
 		t.Error("Expected error to contain base64 error message, but got", err.Error())
 	}
 }

pkg/scalers/azure/azure_queue_test.go

@@ -2,8 +2,9 @@ package azure
 
 import (
 	"context"
+	"encoding/base64"
+	"errors"
 	"net/http"
-	"strings"
 	"testing"
 
 	kedav1alpha1 "github.com/kedacore/keda/v2/apis/keda/v1alpha1"
@@ -19,7 +20,7 @@ func TestGetQueueLength(t *testing.T) {
 		t.Error("Expected error for empty connection string, but got nil")
 	}
 
-	if !strings.Contains(err.Error(), "parse storage connection string") {
+	if !errors.Is(err, ErrAzureConnectionStringKeyName) {
 		t.Error("Expected error to contain parsing error message, but got", err.Error())
 	}
 
@@ -33,7 +34,8 @@ func TestGetQueueLength(t *testing.T) {
 		t.Error("Expected error for empty connection string, but got nil")
 	}
 
-	if !strings.Contains(err.Error(), "illegal base64") {
+	var base64Error base64.CorruptInputError
+	if !errors.As(err, &base64Error) {
 		t.Error("Expected error to contain base64 error message, but got", err.Error())
 	}
 }

pkg/scalers/azure/azure_storage.go

@@ -55,6 +55,14 @@ const (
 	storageResource = "https://storage.azure.com/"
 )
 
+var (
+	// ErrAzureConnectionStringKeyName indicates an error in the connection string AccountKey or AccountName.
+	ErrAzureConnectionStringKeyName = errors.New("can't parse storage connection string. Missing key or name")
+
+	// ErrAzureConnectionStringEndpoint indicates an error in the connection string DefaultEndpointsProtocol or EndpointSuffix.
+	ErrAzureConnectionStringEndpoint = errors.New("can't parse storage connection string. Missing DefaultEndpointsProtocol or EndpointSuffix")
+)
+
 // Prefix returns prefix for a StorageEndpointType
 func (e StorageEndpointType) Prefix() string {
 	return [...]string{"BlobEndpoint", "QueueEndpoint", "TableEndpoint", "FileEndpoint"}[e]
@@ -169,7 +177,7 @@ func parseAzureStorageConnectionString(connectionString string, endpointType Sto
 	}
 
 	if name == "" || key == "" {
-		return nil, "", "", errors.New("can't parse storage connection string. Missing key or name")
+		return nil, "", "", ErrAzureConnectionStringKeyName
 	}
 
 	if endpoint != "" {
@@ -181,7 +189,7 @@ func parseAzureStorageConnectionString(connectionString string, endpointType Sto
 	}
 
 	if endpointProtocol == "" || endpointSuffix == "" {
-		return nil, "", "", errors.New("can't parse storage connection string. Missing DefaultEndpointsProtocol or EndpointSuffix")
+		return nil, "", "", ErrAzureConnectionStringEndpoint
 	}
 
 	u, err := url.Parse(fmt.Sprintf("%s://%s.%s.%s", endpointProtocol, name, endpointType.Name(), endpointSuffix))