Specify error types

configcat_client_test.go

@@ -504,6 +504,18 @@ func TestClient_GetWithInvalidConfig(t *testing.T) {
 	c.Assert(result, qt.Equals, "default")
 }
 
+func TestClient_GetDetails_WithInvalidConfig(t *testing.T) {
+	c := qt.New(t)
+	srv, client := getTestClients(t)
+	srv.setResponse(configResponse{body: "invalid-json"})
+	client.Refresh(context.Background())
+	result := client.GetStringValueDetails("key", "default", nil)
+	_, ok := result.Data.Error.(ErrConfigJsonMissing)
+	c.Assert(ok, qt.IsTrue)
+	c.Assert(result.Data.IsDefaultValue, qt.IsTrue)
+	c.Assert(result.Value, qt.Equals, "default")
+}
+
 func TestClient_GetInt(t *testing.T) {
 	c := qt.New(t)
 	srv, client := getTestClients(t)
@@ -751,6 +763,66 @@ func TestClient_GetFloatDetails_NotExist(t *testing.T) {
 	c.Assert(details.Value, qt.Equals, float64(0))
 }
 
+func TestClient_GetBoolDetails_TypeMismatch(t *testing.T) {
+	c := qt.New(t)
+	srv := newConfigServer(t)
+	srv.setResponse(configResponse{
+		body: contentForIntegrationTestKey("PKDVCLf-Hq-h-kCzMp-L7Q/psuH7BGHoUmdONrzzUOY7A"),
+	})
+	client := NewCustomClient(srv.config())
+	client.Refresh(context.Background())
+
+	details := client.GetBoolValueDetails("integerDefaultOne", false, nil)
+	_, ok := details.Data.Error.(ErrSettingTypeMismatch)
+	c.Assert(ok, qt.IsTrue)
+	c.Assert(details.Value, qt.IsFalse)
+}
+
+func TestClient_GetStringDetails_TypeMismatch(t *testing.T) {
+	c := qt.New(t)
+	srv := newConfigServer(t)
+	srv.setResponse(configResponse{
+		body: contentForIntegrationTestKey("PKDVCLf-Hq-h-kCzMp-L7Q/psuH7BGHoUmdONrzzUOY7A"),
+	})
+	client := NewCustomClient(srv.config())
+	client.Refresh(context.Background())
+
+	details := client.GetStringValueDetails("integerDefaultOne", "", nil)
+	_, ok := details.Data.Error.(ErrSettingTypeMismatch)
+	c.Assert(ok, qt.IsTrue)
+	c.Assert(details.Value, qt.Equals, "")
+}
+
+func TestClient_GetIntDetails_TypeMismatch(t *testing.T) {
+	c := qt.New(t)
+	srv := newConfigServer(t)
+	srv.setResponse(configResponse{
+		body: contentForIntegrationTestKey("PKDVCLf-Hq-h-kCzMp-L7Q/psuH7BGHoUmdONrzzUOY7A"),
+	})
+	client := NewCustomClient(srv.config())
+	client.Refresh(context.Background())
+
+	details := client.GetIntValueDetails("boolDefaultTrue", 0, nil)
+	_, ok := details.Data.Error.(ErrSettingTypeMismatch)
+	c.Assert(ok, qt.IsTrue)
+	c.Assert(details.Value, qt.Equals, 0)
+}
+
+func TestClient_GetFloatDetails_TypeMismatch(t *testing.T) {
+	c := qt.New(t)
+	srv := newConfigServer(t)
+	srv.setResponse(configResponse{
+		body: contentForIntegrationTestKey("PKDVCLf-Hq-h-kCzMp-L7Q/psuH7BGHoUmdONrzzUOY7A"),
+	})
+	client := NewCustomClient(srv.config())
+	client.Refresh(context.Background())
+
+	details := client.GetFloatValueDetails("boolDefaultTrue", 0, nil)
+	_, ok := details.Data.Error.(ErrSettingTypeMismatch)
+	c.Assert(ok, qt.IsTrue)
+	c.Assert(details.Value, qt.Equals, float64(0))
+}
+
 func TestClient_GetDetails_Reflected_User(t *testing.T) {
 	c := qt.New(t)
 	srv := newConfigServer(t)

errors.go

@@ -0,0 +1,52 @@
+package configcat
+
+import (
+	"fmt"
+	"strings"
+)
+
+// ErrKeyNotFound is returned when a key is not found in the configuration.
+type ErrKeyNotFound struct {
+	Key           string
+	AvailableKeys []string
+}
+
+func (e ErrKeyNotFound) Error() string {
+	var availableKeys = ""
+	if len(e.AvailableKeys) > 0 {
+		availableKeys = "'" + strings.Join(e.AvailableKeys, "', '") + "'"
+	}
+	return fmt.Sprintf(
+		"failed to evaluate setting '%s' (the key was not found in config JSON); available keys: [%s]",
+		e.Key,
+		availableKeys,
+	)
+}
+
+// ErrSettingTypeMismatch is returned when a requested setting type doesn't match with the expected type.
+type ErrSettingTypeMismatch struct {
+	Key          string
+	Value        interface{}
+	ExpectedType string
+}
+
+func (e ErrSettingTypeMismatch) Error() string {
+	return fmt.Sprintf(
+		"the type of the setting '%s' doesn't match with the expected type; setting's type was '%t' but the expected type was '%s'",
+		e.Key,
+		e.Value,
+		e.ExpectedType,
+	)
+}
+
+// ErrConfigJsonMissing is returned when the config JSON is empty or missing.
+type ErrConfigJsonMissing struct {
+	Key string
+}
+
+func (e ErrConfigJsonMissing) Error() string {
+	return fmt.Sprintf(
+		"config JSON is not present when evaluating setting '%s'; returning the `defaultValue` parameter that you specified in your application",
+		e.Key,
+	)
+}

flag.go

@@ -1,7 +1,6 @@
 package configcat
 
 import (
-	"fmt"
 	"sync"
 )
 
@@ -84,7 +83,7 @@ func (f BoolFlag) GetValueDetails(snap *Snapshot) EvaluationDetails {
 	}
 	boolVal, ok := details.Value.(bool)
 	if !ok {
-		return produceDetailsWithError(f.key, f.defaultValue, snap, fmt.Errorf("could not convert %s to bool", details.Value))
+		return produceDetailsWithError(f.key, f.defaultValue, snap, ErrSettingTypeMismatch{Key: f.key, ExpectedType: "bool", Value: details.Value})
 	}
 	details.Value = boolVal
 	return details
@@ -144,7 +143,7 @@ func (f IntFlag) GetValueDetails(snap *Snapshot) EvaluationDetails {
 	}
 	intVal, ok := convertInt(details.Value)
 	if !ok {
-		return produceDetailsWithError(f.key, f.defaultValue, snap, fmt.Errorf("could not convert %s to int", details.Value))
+		return produceDetailsWithError(f.key, f.defaultValue, snap, ErrSettingTypeMismatch{Key: f.key, ExpectedType: "int", Value: details.Value})
 	}
 	details.Value = intVal
 	return details
@@ -204,7 +203,7 @@ func (f StringFlag) GetValueDetails(snap *Snapshot) EvaluationDetails {
 	}
 	stringVal, ok := details.Value.(string)
 	if !ok {
-		return produceDetailsWithError(f.key, f.defaultValue, snap, fmt.Errorf("could not convert %s to string", details.Value))
+		return produceDetailsWithError(f.key, f.defaultValue, snap, ErrSettingTypeMismatch{Key: f.key, ExpectedType: "string", Value: details.Value})
 	}
 	details.Value = stringVal
 	return details
@@ -264,7 +263,7 @@ func (f FloatFlag) GetValueDetails(snap *Snapshot) EvaluationDetails {
 	}
 	floatVal, ok := details.Value.(float64)
 	if !ok {
-		return produceDetailsWithError(f.key, f.defaultValue, snap, fmt.Errorf("could not convert %s to float64", details.Value))
+		return produceDetailsWithError(f.key, f.defaultValue, snap, ErrSettingTypeMismatch{Key: f.key, ExpectedType: "float", Value: details.Value})
 	}
 	details.Value = floatVal
 	return details

snapshot.go

@@ -4,30 +4,11 @@ import (
 	"errors"
 	"fmt"
 	"reflect"
-	"strings"
 	"sync"
 	"sync/atomic"
 	"time"
 )
 
-// ErrKeyNotFound is returned when a key is not found in the configuration.
-type ErrKeyNotFound struct {
-	Key           string
-	AvailableKeys []string
-}
-
-func (e ErrKeyNotFound) Error() string {
-	var availableKeys = ""
-	if len(e.AvailableKeys) > 0 {
-		availableKeys = "'" + strings.Join(e.AvailableKeys, "', '") + "'"
-	}
-	return fmt.Sprintf(
-		"failed to evaluate setting '%s' (the key was not found in config JSON); available keys: [%s]",
-		e.Key,
-		availableKeys,
-	)
-}
-
 // Snapshot holds a snapshot of the ConfigCat configuration.
 // A snapshot is immutable once taken.
 //
@@ -224,6 +205,11 @@ func (snap *Snapshot) details(id keyID, key string) (interface{}, string, *Targe
 	if snap == nil {
 		return nil, "", nil, nil, errors.New("snapshot is nil")
 	}
+	if snap.evaluators == nil {
+		err := ErrConfigJsonMissing{Key: key}
+		snap.logger.Errorf(1000, err.Error())
+		return nil, "", nil, nil, err
+	}
 	var eval settingEvalFunc
 	if int(id) < len(snap.evaluators) {
 		eval = snap.evaluators[id]