From 95bb00d1088767ed14e3bd1a5f533a690d619a5f Mon Sep 17 00:00:00 2001 From: Carlos Alexandro Becker Date: Sun, 13 Sep 2020 02:12:02 +0000 Subject: encoding/json: implement Is on all errors Allows users to check: errors.Is(err, &UnmarshalTypeError{}) errors.Is(err, &UnmarshalFieldError{}) errors.Is(err, &InvalidUnmarshalError{}) errors.Is(err, &UnsupportedValueError{}) errors.Is(err, &MarshalerError{}) which is the recommended way of checking for kinds of errors. SyntaxError.Is was implemented in CL 253037. As and Unwrap relevant methods will be added in future CLs. Change-Id: I1f8a503b8fdc0f3afdfe9669a91f3af8d960e028 GitHub-Last-Rev: 930cda5384c987a0b31f277ba3b4ab690ea74ac3 GitHub-Pull-Request: golang/go#41360 Reviewed-on: https://go-review.googlesource.com/c/go/+/254537 Run-TryBot: Emmanuel Odeke TryBot-Result: Gobot Gobot Reviewed-by: Emmanuel Odeke Trust: Emmanuel Odeke --- src/encoding/json/decode.go | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) (limited to 'src/encoding/json/decode.go') diff --git a/src/encoding/json/decode.go b/src/encoding/json/decode.go index 86d8a69db7..1b006ffb17 100644 --- a/src/encoding/json/decode.go +++ b/src/encoding/json/decode.go @@ -136,6 +136,12 @@ func (e *UnmarshalTypeError) Error() string { return "json: cannot unmarshal " + e.Value + " into Go value of type " + e.Type.String() } +// Is returns true if target is a UnmarshalTypeError. +func (e *UnmarshalTypeError) Is(target error) bool { + _, ok := target.(*UnmarshalTypeError) + return ok +} + // An UnmarshalFieldError describes a JSON object key that // led to an unexported (and therefore unwritable) struct field. // @@ -150,12 +156,24 @@ func (e *UnmarshalFieldError) Error() string { return "json: cannot unmarshal object key " + strconv.Quote(e.Key) + " into unexported field " + e.Field.Name + " of type " + e.Type.String() } +// Is returns true if target is a UnmarshalFieldError. +func (e *UnmarshalFieldError) Is(target error) bool { + _, ok := target.(*UnmarshalFieldError) + return ok +} + // An InvalidUnmarshalError describes an invalid argument passed to Unmarshal. // (The argument to Unmarshal must be a non-nil pointer.) type InvalidUnmarshalError struct { Type reflect.Type } +// Is returns true if target is a InvalidUnmarshalError. +func (e *InvalidUnmarshalError) Is(target error) bool { + _, ok := target.(*InvalidUnmarshalError) + return ok +} + func (e *InvalidUnmarshalError) Error() string { if e.Type == nil { return "json: Unmarshal(nil)" -- cgit v1.3-6-g1900