golang/go

encoding/json: interface{} not being stringified when JSON ",string" tag is used

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#32,055 opened on May 15, 2019

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Description

What version of Go are you using (go version)?

1.12.5 playground

Does this issue reproduce with the latest release?

yes

What operating system and processor architecture are you using (go env)?

NACL

What did you do?

https://play.golang.org/p/Q4JdghzkBI-

What did you expect to see?

interface{} fields that point to integers should be converted to strings when the string tag is used.

The documentation says:
It applies only to fields of string, floating point, integer, or boolean types

but it also says:

Interface values encode as the value contained in the interface. A nil interface value encodes as the null JSON value.

What did you see instead?

They were not converted to strings.

Contributor guide

Research direction
Investigate the encoding/json encoder's handling of the `string` tag for interface{} fields. Trace the code path in `encode.go` where struct fields are processed and see why the tag is ignored for interface types.
Tech stack
go
Domain
backend
Issue type
Bug
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
2
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
1-3 hours
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
Active
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
Clear
Prerequisites
Go
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
70