implement TextMarshaler/JSONMarshaler more consistently

[imjasonh]

Various things in the Go ecosystem natively understand how to go from string->Foo if Foo implements TextUnmarshaler, and likewise from Foo->string if Foo implements TextMarshaler.

This adds TextMarshaler and JSONMarshaler support to name.Registry, name.Repository, name.Tag, and name.Digest, and makes v1.Hash's implementation a bit more consistent with those (using json.Unmarshal instead of strconv.Unquote)

[Copilot]

Pull Request Overview

This PR adds consistent JSON and text (un)marshaling support to v1.Hash and the name package types (Tag, Repository, Registry, Digest).

• Switches v1.Hash from strconv.Unquote to json.Unmarshal and condenses marshal methods.
• Implements MarshalJSON, UnmarshalJSON, MarshalText, and UnmarshalText for Tag, Repository, Registry, and Digest.
• Removes the unused strconv import in pkg/v1/hash.go.

Reviewed Changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 8 comments.

Show a summary per file

File	Description
pkg/v1/hash.go	Updates Hash JSON methods and removes strconv import
pkg/name/tag.go	Adds JSON/Text marshaling for Tag
pkg/name/repository.go	Adds JSON/Text marshaling for Repository
pkg/name/registry.go	Adds JSON/Text marshaling for Registry
pkg/name/digest.go	Adds Text marshaling for Digest

Comments suppressed due to low confidence (2)

pkg/v1/hash.go:21

• The code calls json.Marshal and json.Unmarshal but the encoding/json package is not imported; add "encoding/json" to the imports.

import (

pkg/name/tag.go:112

• [nitpick] Consider adding unit tests for Tag.MarshalJSON and Tag.UnmarshalJSON to ensure correct serialization and error handling.

func (t Tag) MarshalJSON() ([]byte, error) { return json.Marshal(t.String()) }