refactor!: Rename EditComment to UpdateComment on IssuesService, and pass a new IssueCommentRequest by value

[JamBalaya56562]

Continues the request-body-by-value work in #3644, this time for the issue comment endpoints on IssuesService.

CreateComment and EditComment reused the 11-field IssueComment response type as their request bodies, but per the docs both endpoints accept exactly one parameter, body, and it's required in both. The other ten fields (id, user, reactions, created_at, …) are server-generated. The clearest evidence is in the code itself — EditComment's doc comment had to warn:

A non-nil comment.Body must be provided. Other comment fields should be left nil.

The new request type makes that warning unnecessary by construction:

type IssueCommentRequest struct {
	Body string `json:"body"`
}

Unlike the milestone split in #4438, the create and update schemas here are identical, so a single shared request type is used rather than a create/update pair (same reasoning as HookConfig in #4360). Body is a non-pointer string since it's required in both operations.

EditComment is renamed to UpdateComment to match the docs operation name, Update an issue comment (same convention as #4438/#4400). Both methods now take the body by value, and IssueComment is removed from the body-allowed-pointer-types allowlist. The IssueComment response type itself is unchanged.

Verified with go build ./..., go vet -tags integration ./test/integration/, gofmt, the full ./github/ test suite (both methods and the generated GetBody at 100%), and custom-gcl (no paramcheck findings after removing the allowlist entry).

Updates #3644

BREAKING CHANGE: IssuesService.CreateComment now takes a new IssueCommentRequest (with non-pointer Body) by value, and IssuesService.EditComment is renamed to UpdateComment and takes the same IssueCommentRequest by value, instead of *IssueComment.

cc @jvm986 — second item in the Issues service; as before, happy to coordinate whenever you resume.

[gmlewis]

Congratulations, @JamBalaya56562 on PR #4444 !!! 😂

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 97.55%. Comparing base (848675f) to head (3d99db7).

Additional details and impacted files

@@           Coverage Diff           @@
##           master    #4444   +/-   ##
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  Coverage   97.55%   97.55%           
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  Files         194      194           
  Lines       19892    19892           
=======================================
  Hits        19406    19406           
  Misses        268      268           
  Partials      218      218           

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[gmlewis]

Thank you, @JamBalaya56562!
LGTM.
Awaiting second LGTM+Approval from any other contributor to the repo before merging.

cc: @stevehipwell - @alexandear - @Not-Dhananjay-Mishra

[Not-Dhananjay-Mishra]

Let's also update IssueComment struct.

// IssueComment represents a comment left on an issue.
type IssueComment struct {
	ID        *int64     `json:"id,omitempty"`
	NodeID    *string    `json:"node_id,omitempty"`
	Body      *string    `json:"body,omitempty"`
	User      *User      `json:"user,omitempty"`
	Reactions *Reactions `json:"reactions,omitempty"`
	CreatedAt *Timestamp `json:"created_at,omitempty"`
	UpdatedAt *Timestamp `json:"updated_at,omitempty"`
	// AuthorAssociation is the comment author's relationship to the issue's repository.
	// Possible values are "COLLABORATOR", "CONTRIBUTOR", "FIRST_TIMER", "FIRST_TIME_CONTRIBUTOR", "MEMBER", "OWNER", or "NONE".
	//
	// Deprecated: GitHub will remove this field from Events API payloads on October 7, 2025.
	// Use the Issue Comments REST API endpoint to retrieve this information.
	// See: https://docs.github.com/rest/issues/comments?apiVersion=2022-11-28#get-an-issue-comment
	AuthorAssociation *string `json:"author_association,omitempty"`
	URL               *string `json:"url,omitempty"`
	HTMLURL           *string `json:"html_url,omitempty"`
	IssueURL          *string `json:"issue_url,omitempty"`
}

It has few missing fields - performed_via_github_app, pin and minimized
https://docs.github.com/en/rest/issues/comments?apiVersion=2022-11-28#update-an-issue-comment

[JamBalaya56562]

It has few missing fields - performed_via_github_app, pin and minimized

Thanks @Not-Dhananjay-Mishra — added in 96e0bc1. I verified all three against the issue-comment response schema:

• PerformedViaGithubApp *App — same shape as the existing five uses of performed_via_github_app in the codebase (Issue, IssueEvent, Timeline, …).
• Pin *PinnedIssueComment — new type with PinnedAt *Timestamp / PinnedBy *User, matching the "Pinned Issue Comment" schema.
• Minimized *MinimizedIssueComment — new type with Reason *string, matching the "Minimized Issue Comment" schema.

All three are nullable in the response, so they're pointers with omitempty, and the generated accessors are covered at 100%.