prepare 2.0.1 release (#12)

Author: LaunchDarklyCI

lduser/user_serialization.go

@@ -2,15 +2,17 @@ package lduser
 
 import (
 	"encoding/json"
-	"errors"
+	"reflect"
 
 	"gopkg.in/launchdarkly/go-sdk-common.v2/jsonstream"
 	"gopkg.in/launchdarkly/go-sdk-common.v2/ldvalue"
 )
 
-var (
-	errMissingKey = errors.New("")
-)
+type missingKeyError struct{}
+
+func (e missingKeyError) Error() string {
+	return "User must have a key property"
+}
 
 // ErrMissingKey returns the standard error value that is used if you try to unmarshal a user from JSON
 // and the "key" property is either absent or null. This is distinguished from other kinds of unmarshaling
@@ -20,7 +22,7 @@ var (
 // LaunchDarkly does allow a user to have an empty string ("") as a key in some cases, but this is
 // discouraged since analytics events will not work properly without unique user keys.
 func ErrMissingKey() error {
-	return errMissingKey
+	return missingKeyError{}
 }
 
 // This temporary struct allows us to do JSON unmarshalling as efficiently as possible while not requiring
@@ -76,13 +78,23 @@ func (u User) MarshalJSON() ([]byte, error) {
 // Any property that is either completely omitted or has a null value is ignored and left in an unset
 // state, except for "key". All users must have a key (even if it is ""), so an omitted or null "key"
 // property causes the error ErrMissingKey().
+//
+// Trying to unmarshal any non-struct value, including a JSON null, into a User will return a
+// json.UnmarshalTypeError. If you want to unmarshal optional user data that might be null, use *User
+// instead of User.
 func (u *User) UnmarshalJSON(data []byte) error {
+	// Special handling here for a null value - json.Unmarshal will normally treat a null exactly like
+	// "{}" when unmarshaling a struct. We don't want that, because it will produce a misleading
+	// "missing key" error further down. Instead, just treat it as an invalid type.
+	if string(data) == "null" {
+		return &json.UnmarshalTypeError{Value: string(data), Type: reflect.TypeOf(u)}
+	}
 	var ufs userForDeserialization
 	if err := json.Unmarshal(data, &ufs); err != nil {
 		return err
 	}
 	if !ufs.Key.IsDefined() {
-		return errMissingKey
+		return ErrMissingKey()
 	}
 	*u = User{
 		key:       ufs.Key.StringValue(),

lduser/user_serialization_test.go

@@ -150,10 +150,19 @@ func TestJSONUnmarshalPrivateAttributes(t *testing.T) {
 	assert.True(t, user2.IsPrivateAttribute("name"))
 }
 
-func TestJSONUnmarshalMalformedData(t *testing.T) {
+func TestJSONUnmarshalDataWithWrongFieldType(t *testing.T) {
 	var user User
 	err := json.Unmarshal([]byte(`{"key":[1,2,3]}`), &user)
-	assert.Error(t, err)
+	assert.IsType(t, &json.UnmarshalTypeError{}, err)
+}
+
+func TestJSONUnmarshalNonStructData(t *testing.T) {
+	var user User
+	assert.IsType(t, &json.UnmarshalTypeError{}, json.Unmarshal([]byte(`null`), &user))
+	assert.IsType(t, &json.UnmarshalTypeError{}, json.Unmarshal([]byte(`true`), &user))
+	assert.IsType(t, &json.UnmarshalTypeError{}, json.Unmarshal([]byte(`3`), &user))
+	assert.IsType(t, &json.UnmarshalTypeError{}, json.Unmarshal([]byte(`"x"`), &user))
+	assert.IsType(t, &json.UnmarshalTypeError{}, json.Unmarshal([]byte(`[]`), &user))
 }
 
 func TestJSONUnmarshalUserKeyValidation(t *testing.T) {
@@ -177,3 +186,7 @@ func TestJSONUnmarshalUserKeyValidation(t *testing.T) {
 		assert.Equal(t, "n", user.GetName().StringValue())
 	})
 }
+
+func TestMissingKeyHasErrorMessage(t *testing.T) {
+	assert.NotEqual(t, "", ErrMissingKey().Error())
+}

ldvalue/optional_bool.go

@@ -1,7 +1,8 @@
 package ldvalue
 
 import (
-	"errors"
+	"encoding/json"
+	"reflect"
 
 	"gopkg.in/launchdarkly/go-sdk-common.v2/jsonstream"
 )
@@ -127,7 +128,7 @@ func (o *OptionalBool) UnmarshalJSON(data []byte) error {
 		*o = NewOptionalBool(v.BoolValue())
 	default:
 		*o = OptionalBool{}
-		return errors.New("expected boolean or null")
+		return &json.UnmarshalTypeError{Value: string(data), Type: reflect.TypeOf(o)}
 	}
 	return nil
 }

ldvalue/optional_bool_test.go

@@ -113,9 +113,11 @@ func TestOptionalBoolJSONUnmarshalling(t *testing.T) {
 
 	err = json.Unmarshal([]byte(`3`), &o)
 	assert.Error(t, err)
+	assert.IsType(t, &json.UnmarshalTypeError{}, err)
 
 	err = json.Unmarshal([]byte(`x`), &o)
 	assert.Error(t, err)
+	assert.IsType(t, &json.SyntaxError{}, err)
 
 	var swos structWithOptionalBools
 	err = json.Unmarshal([]byte(`{"b1":true,"b2":false,"b3":null}`), &swos)

ldvalue/optional_int.go

@@ -1,7 +1,8 @@
 package ldvalue
 
 import (
-	"errors"
+	"encoding/json"
+	"reflect"
 	"strconv"
 
 	"gopkg.in/launchdarkly/go-sdk-common.v2/jsonstream"
@@ -125,7 +126,7 @@ func (o *OptionalInt) UnmarshalJSON(data []byte) error {
 		*o = NewOptionalInt(v.IntValue())
 	default:
 		*o = OptionalInt{}
-		return errors.New("expected integer or null")
+		return &json.UnmarshalTypeError{Value: string(data), Type: reflect.TypeOf(o)}
 	}
 	return nil
 }

ldvalue/optional_int_test.go

@@ -96,9 +96,11 @@ func TestOptionalIntJSONUnmarshalling(t *testing.T) {
 
 	err = json.Unmarshal([]byte(`true`), &o)
 	assert.Error(t, err)
+	assert.IsType(t, &json.UnmarshalTypeError{}, err)
 
 	err = json.Unmarshal([]byte(`x`), &o)
 	assert.Error(t, err)
+	assert.IsType(t, &json.SyntaxError{}, err)
 
 	var swos structWithOptionalInts
 	err = json.Unmarshal([]byte(`{"n1":3,"n3":null}`), &swos)

ldvalue/optional_string.go

@@ -2,7 +2,7 @@ package ldvalue
 
 import (
 	"encoding/json"
-	"errors"
+	"reflect"
 
 	"gopkg.in/launchdarkly/go-sdk-common.v2/jsonstream"
 )
@@ -147,7 +147,7 @@ func (o *OptionalString) UnmarshalJSON(data []byte) error {
 		*o = NewOptionalString(v.StringValue())
 	default:
 		*o = OptionalString{}
-		return errors.New("expected string or null")
+		return &json.UnmarshalTypeError{Value: string(data), Type: reflect.TypeOf(o)}
 	}
 	return nil
 }

ldvalue/optional_string_test.go

@@ -104,6 +104,7 @@ func TestOptionalStringJSONUnmarshalling(t *testing.T) {
 
 	err = json.Unmarshal([]byte("3"), &o)
 	assert.Error(t, err)
+	assert.IsType(t, &json.UnmarshalTypeError{}, err)
 	assert.False(t, o.IsDefined())
 
 	var swos structWithOptionalStrings

ldvalue/value_serialization.go

@@ -3,7 +3,6 @@ package ldvalue
 import (
 	"encoding/json"
 	"errors"
-	"fmt"
 	"strconv"
 
 	"gopkg.in/launchdarkly/go-sdk-common.v2/jsonstream"
@@ -144,7 +143,7 @@ func (v *Value) UnmarshalJSON(data []byte) error { //nolint:funlen // yes, we kn
 		}
 		return e
 	}
-	return fmt.Errorf("unknown JSON token: %s", data) // COVERAGE: never happens, parser rejects the token earlier
+	return &json.SyntaxError{} // COVERAGE: never happens, parser rejects the token earlier
 }
 
 // WriteToJSONBuffer provides JSON serialization for Value with the jsonstream API.