WIP: test(CHANGELOG): add changelog: released entry changed label escape hatch

TODO: check for label in action, plumb option to still succeed? TODO: test it out TODO: docs

Author: ErichDonGubler

.github/workflows/changelog.yml

@@ -7,6 +7,8 @@ on:
  - opened
  - synchronize
  - reopened
+ - labeled
+ - unlabeled
 
 env:
  #
@@ -39,6 +41,7 @@ jobs:
  with:
  fetch-depth: 0
 
+ # NOTE: Keep label name(s) in sync. with `xtask`'s implementation.
  - name: Run `cargo xtask changelog …`
  run: |
- cargo xtask changelog --emit-github-messages "origin/${{ github.event.pull_request.base.ref }}" >> "$GITHUB_STEP_SUMMARY"
+ cargo xtask changelog --emit-github-messages ${{ contains(github.event.issue.labels.*.name, 'changelog: released entry changed') && '--warn-only' || '' }} "origin/${{ github.event.pull_request.base.ref }}" >> "$GITHUB_STEP_SUMMARY"

xtask/src/changelog.rs

@@ -3,8 +3,10 @@ use xshell::Shell;
 
 pub(crate) fn check_changelog(shell: Shell, mut args: Arguments) -> anyhow::Result<()> {
  const CHANGELOG_PATH_RELATIVE: &str = "./CHANGELOG.md";
+ const WARN_LABEL: &str = "changelog: released entry changed";
 
  let emit_github_messages = args.contains("--emit-github-messages");
+ let warn_only = args.contains("--warn-only");
 
  let from_branch = args
  .free_from_str()
@@ -65,11 +67,24 @@ pub(crate) fn check_changelog(shell: Shell, mut args: Arguments) -> anyhow::Resu
  eprintln!("{}", hunk.contents);
 
  if emit_github_messages {
+ let severity = if warn_only { "warning" } else { "error" };
  let title = "Released changelog content changed";
- let message =
+ let mut message =
  "This PR changes changelog content that is already released.".to_owned();
+ if !warn_only {
+ // NOTE: Keep this label name in sync. with CI's branching logic.
+ message += &format!(
+ concat!(
+ "\n\n",
+ "If you know what you're doing, ",
+ "you can add the `{}` label ",
+ "and reduce this error's severity to a warning."
+ ),
+ WARN_LABEL
+ );
+ }
  println!(
- "::error file=CHANGELOG.md,line={},endLine={},title={title}::{message}",
+ "::{severity} file=CHANGELOG.md,line={},endLine={},title={title}::{message}",
  hunk.change_start_line_num, hunk.change_end_line_num,
  )
  }
@@ -82,7 +97,12 @@ pub(crate) fn check_changelog(shell: Shell, mut args: Arguments) -> anyhow::Resu
  "one or more checks against `{}` failed; see above for details",
  CHANGELOG_PATH_RELATIVE,
  );
- Err(anyhow::Error::msg(msg))
+ if warn_only {
+ log::warn!("{msg}");
+ Ok(())
+ } else {
+ Err(anyhow::Error::msg(msg))
+ }
  } else {
  Ok(())
  }