Pr Description

Authoring GitHub Prose for dotnet/fsharp

Reviewers can already see the Files tab, the commit log, and the issue thread. Say what behavior changed and why, in as few words as possible.

Rules

Rules 1, 2, 4, 5, 6 are defaults; if the user insists, push back once then comply. Rule 3 is non-negotiable — -b "..." ships broken markdown (see PR #19866).

1. No change inventory. No file/module/method/test lists. No ## Changes/## Implementation section. Mention an identifier only when it is the user-visible behavior. Whatever the reader already has (Files tab for PRs, commit log for follow-up comments, issue history for issue edits) — don't re-list it.
2. No LLM slop, no justification scaffolding. No emoji headers, no "TL;DR" above a 3-line body, no Motivation/Background/Approach/Testing sections, no re-stating the title or the comment you're replying to. No "matching the X norm", no "preventing the Y failure (PR #ZZZZ)", no stats, no links to past PRs as proof. The diff is the proof.
3. Body via --body-file, built without shell expansion. Write the file with your file-creation/edit tool (it writes bytes verbatim — no $/backtick evaluation, no delimiter collisions, OS-agnostic). Never -b "..." / --body "..." — backticks and $ get shell-evaluated and the render breaks. If you build the file in a shell, use a pwsh verbatim here-string @'...'@ (cross-platform; single-quoted is mandatory). Applies to gh pr create/edit/comment/review, gh issue create/edit/comment.
4. Fixes #N to close issues. Use only when the PR actually closes #N (auto-closes on merge). It is the highest-value line in most PR bodies — never omit it when valid. No "Related to" / speculative links. Preserve existing trailers (Co-authored-by:, Signed-off-by:, Reverts #N); don't invent them.
5. Title: imperative, ≤72 chars, no trailing period, no fix:/feat: prefix. Name the behavior, not the file. A specific title lets the body shrink to Fixes #N + one sentence.
6. No hard-wrapped prose. Write each paragraph as one unbroken line and let GitHub's renderer wrap it — blank lines separate paragraphs, and that's the only break you author. Manual mid-sentence line breaks (wrapping at a fixed column) are a machine tell and render raggedly across window widths.

PR-body shapes (pick the smallest that carries the signal)

One-liner for bumps / mechanical fixes:

Update .NET SDK from 10.0.202 to 10.0.204.

Title carries the construct + issue link — preferred when the title is specific:

Fixes #18009

Wrong colorization when a qualified type name with generic parameters is used in a static member access expression.

Issue link + 1-sentence why — the most common non-trivial shape:

Fixes #19751

`--refout` MVIDs were unstable because hashing relied on per-process string randomization. Switched to a deterministic hash.

Before/After code block — when prose loses information; ≤15 lines, language tag:

Fixes #15803

```fsharp
let f (x: int) = x <- 1
// before: FS0027 suggested `let mutable x = expression` (illegal for parameters)
// after:  FS0027 suggests `let mutable x = x` shadow or `byref<_>`
```

Behavior-changes bullet list — for genuinely multi-behavior PRs. 3–5 bullets naming behaviors, never files/modules; if bullets map 1:1 to files, collapse to prose or split the PR:

Fixes #19710
Fixes #19720

- `match x with null` now preserves type aliases.
- FS0027 on parameters suggests `let mutable x = x` shadow / `byref<_>`.
- `let _ = &expr` compiles like `let x = &expr`.

Prefer inline backticks for short identifiers over a fenced block. Fenced blocks are the exception — use only when prose loses information.

Comments / review summaries: same rules, no title. Usually 1–3 sentences. Quote-reply only the line you're responding to; don't restate it.

Workflow

Show the title + body (or comment text) in chat first. Do not run gh until the user approves. Then:

1. Write the body to a file with your file-creation tool (bytes verbatim, OS-agnostic, avoids every shell-quoting trap). Or in pwsh:

   @'
   Fix false-positive FS3261 when nullness narrowing leaks across iterations of seq/list/array comprehensions.
   
   Fixes #19644
   '@ | Set-Content -NoNewline pr-body.md
   

2. Post with exactly one:

   gh pr create  --title "<imperative title>" --body-file pr-body.md
   gh pr edit    <N> --body-file pr-body.md     # REPLACES body — read first if extending
   gh pr comment <N> --body-file pr-body.md
   gh pr review  <N> --body-file pr-body.md --comment   # or --approve / --request-changes
   gh issue create  --title "<t>" --body-file pr-body.md
   gh issue edit    <N> --body-file pr-body.md
   gh issue comment <N> --body-file pr-body.md
   

   To extend without losing the existing body: gh pr view <N> --json body -q .body > pr-body.md → edit → gh pr edit <N> --body-file pr-body.md.

3. Verify the live render — fetch the body and compare to the file with your view/diff tool. Fail loudly if gh fetch errors (a piped failure prints an "all-deleted" diff that misreads as "GitHub mangled it").