Indicate which test suites are running in a PR comment

.github/scripts/build-pr-classification-comment.sc

@@ -0,0 +1,115 @@
+#!/usr/bin/env -S scala-cli shebang
+//> using scala 3
+//> using toolkit default
+//> using options -Werror -Wunused:all
+
+//> using file ./pr-classify-lib/Env.scala
+//> using file ./pr-classify-lib/EnvNames.scala
+//> using file ./pr-classify-lib/Category.scala
+//> using file ./pr-classify-lib/OverrideKey.scala
+//> using file ./pr-classify-lib/SuiteGroup.scala
+//> using file ./pr-classify-lib/Signals.scala
+//> using file ./pr-classify-lib/KeyValueFile.scala
+
+// Builds the Markdown body for the PR sticky comment that summarizes how the
+// `changes` job classified the diff and which suite groups will run / be
+// skipped. Intended to be invoked from `ci.yml`'s `changes` job so the
+// resulting comment reflects the exact classification CI is using; the
+// `pr-classify-comment.yml` workflow then downloads the rendered body as
+// an artifact and posts it as a sticky PR comment.
+//
+// Inputs (env vars):
+//   CLASSIFY_OUTPUT_FILE  - KEY=VALUE file produced by classify-changes.sc.
+//   OVERRIDE_OUTPUT_FILE  - KEY=VALUE file produced by check-override-keywords.sc.
+//   COMMENT_OUTPUT_FILE   - Path to write the rendered Markdown to (default: comment.md).
+//   CI_RUN_ID             - Run ID of the CI workflow run (optional).
+//   CI_RUN_URL            - URL to the CI workflow run (optional).
+
+import prclassify.*
+
+/** Which active overrides add suite groups that wouldn't run on their own. */
+def overrideContributions(signals: Signals): Seq[(OverrideKey, Seq[SuiteGroup])] =
+  val baseline     = signals.withoutOverrides
+  val baselineRuns = SuiteGroup.values.iterator.filter(baseline.shouldRun).toSet
+  OverrideKey.ordered.flatMap: key =>
+    if !signals.has(key) then None
+    else
+      val probe = baseline.withOverride(key, enabled = true)
+      val added = SuiteGroup.ordered.filter(g => probe.shouldRun(g) && !baselineRuns.contains(g))
+      if added.isEmpty then None else Some(key -> added)
+
+def renderComment(
+  signals: Signals,
+  ciRunId: Option[String],
+  ciRunUrl: Option[String]
+): String =
+  val (runGroups, skipGroups) = SuiteGroup.ordered.partition(signals.shouldRun)
+
+  val categoryRows = Category.ordered
+    .map(c => s"| ${c.key} | ${signals.has(c)} |")
+    .mkString("\n")
+
+  def listLine(prefix: String, groups: Seq[SuiteGroup]): String =
+    if groups.isEmpty then s"- $prefix: _(none)_"
+    else s"- $prefix: ${groups.map(_.label).mkString(", ")}"
+
+  // categoryRows lines start with `|`, which is stripMargin's margin marker,
+  // so concatenate them after the stripped template instead of interpolating.
+  val headerSection =
+    s"""### CI change classification
+       |
+       |**Change categories**
+       |
+       || Category | Changed |
+       || --- | --- |
+       |""".stripMargin + categoryRows
+
+  val suitesSection =
+    s"""**Suite groups**
+       |
+       |${listLine("Will run", runGroups)}
+       |${listLine("Will be skipped", skipGroups)}""".stripMargin
+
+  val overridesSection: Option[String] = overrideContributions(signals) match
+    case Nil           => None
+    case contributions =>
+      val rows = contributions
+        .map((key, added) => s"- `${key.marker}` forces on: ${added.map(_.label).mkString(", ")}")
+        .mkString("\n")
+      Some(
+        s"""**Override keywords affecting the run set**
+           |
+           |$rows""".stripMargin
+      )
+
+  val ciRunSection: Option[String] = ciRunId match
+    case Some(id) => Some(s"Full CI run: [#$id](${ciRunUrl.getOrElse("")})")
+    case None     => ciRunUrl.map(url => s"Full CI run: $url")
+
+  val sections =
+    Seq(Some(headerSection), Some(suitesSection), overridesSection, ciRunSection).flatten
+
+  sections.mkString("\n\n") + "\n"
+
+val categoryMap = KeyValueFile.read(Env.requiredFile(EnvNames.ClassifyOutputFile))
+val overrideMap = KeyValueFile.read(Env.requiredFile(EnvNames.OverrideOutputFile))
+val signals     = Signals.fromKeyValueMaps(categoryMap, overrideMap)
+
+val commentPath = Env.toAbsolutePath(
+  Env.withDefault(EnvNames.CommentOutputFile, "comment.md")
+)
+
+val body = renderComment(
+  signals,
+  ciRunId = Env.opt(EnvNames.CiRunId),
+  ciRunUrl = Env.opt(EnvNames.CiRunUrl)
+)
+println(
+  s"""Generated comment body:
+     |-----------------------
+     |$body
+     |-----------------------""".stripMargin
+)
+
+os.write.over(commentPath, body, createFolders = true)
+println(s"Wrote comment to $commentPath")

.github/scripts/check-override-keywords.sc

@@ -0,0 +1,59 @@
+#!/usr/bin/env -S scala-cli shebang
+//> using scala 3
+//> using toolkit default
+//> using options -Werror -Wunused:all
+
+//> using file ./pr-classify-lib/Env.scala
+//> using file ./pr-classify-lib/EnvNames.scala
+//> using file ./pr-classify-lib/OverrideKey.scala
+//> using file ./pr-classify-lib/KeyValueFile.scala
+//> using file ./pr-classify-lib/GitHubOutput.scala
+
+// Checks the PR body for [test_*] override keywords.
+// Inputs (env vars):
+//   EVENT_NAME            - GitHub event name (pull_request, push, ...).
+//   PR_BODY               - The PR body to scan for override keywords.
+//   OVERRIDE_OUTPUT_FILE  - Optional path of a KEY=VALUE file to also write
+//                           override results into (in addition to $GITHUB_OUTPUT).
+// Outputs:
+//   - `${keyword}=true|false` to $GITHUB_OUTPUT for every override,
+//   - a Markdown summary table to $GITHUB_STEP_SUMMARY,
+//   - and the same KEY=VALUE pairs to $OVERRIDE_OUTPUT_FILE when set.
+
+import prclassify.*
+
+val eventName = Env.opt(EnvNames.EventName).getOrElse("")
+val prBody    = Env.opt(EnvNames.PrBody).getOrElse("")
+
+val active: Set[OverrideKey] =
+  if eventName != "pull_request" then
+    println("Non-PR event, setting all overrides to true")
+    OverrideKey.values.toSet
+  else OverrideKey.values.iterator.filter(o => prBody.contains(o.marker)).toSet
+
+OverrideKey.ordered.foreach: o =>
+  if active.contains(o) then println(s"Override ${o.marker} found")
+
+println("Override keywords:")
+OverrideKey.ordered.foreach(o => println(s"  ${o.keyword}=${active.contains(o)}"))
+
+val entries: Seq[(String, String)] =
+  OverrideKey.ordered.map(o => o.keyword -> active.contains(o).toString)
+
+entries.foreach((k, v) => GitHubOutput.writeScalar(k, v))
+
+Env.opt(EnvNames.OverrideOutputFile).foreach: path =>
+  KeyValueFile.appendAll(Env.toAbsolutePath(path), entries)
+
+val overrideRows = OverrideKey.ordered
+  .map(o => s"| ${o.marker} | ${active.contains(o)} |")
+  .mkString("\n")
+
+// overrideRows lines start with `|` (stripMargin's margin marker), so
+// concatenate them after the stripped template instead of interpolating.
+GitHubOutput.writeSummary(
+  s"""## Override keywords
+     || Keyword | Active |
+     ||---------|--------|
+     |""".stripMargin + overrideRows
+)

.github/scripts/classify-changes.sc

@@ -0,0 +1,80 @@
+#!/usr/bin/env -S scala-cli shebang
+//> using scala 3
+//> using toolkit default
+//> using options -Werror -Wunused:all
+
+//> using file ./pr-classify-lib/Env.scala
+//> using file ./pr-classify-lib/EnvNames.scala
+//> using file ./pr-classify-lib/Category.scala
+//> using file ./pr-classify-lib/KeyValueFile.scala
+//> using file ./pr-classify-lib/GitHubOutput.scala
+
+// Classifies changed files into categories for CI job filtering.
+// Inputs (env vars):
+//   EVENT_NAME              - GitHub event name (pull_request, push, ...).
+//   BASE_REF                - Base ref of the PR (used to compute the diff).
+//   CHANGED_FILES_OVERRIDE  - Optional newline-separated list of changed files.
+//                             When set, overrides the git-diff-based detection.
+//   CLASSIFY_OUTPUT_FILE    - Optional path of a KEY=VALUE file to also write
+//                             category results into (in addition to $GITHUB_OUTPUT).
+// Outputs:
+//   - `${category}=true|false` to $GITHUB_OUTPUT for every category,
+//   - a Markdown summary table to $GITHUB_STEP_SUMMARY,
+//   - and the same KEY=VALUE pairs to $CLASSIFY_OUTPUT_FILE when set.
+
+import prclassify.*
+
+enum ChangeSet:
+  case All
+  case Specific(files: Seq[String])
+
+def splitLines(s: String): Seq[String] =
+  s.linesIterator.map(_.trim).filter(_.nonEmpty).toIndexedSeq
+
+val eventName = Env.opt(EnvNames.EventName).getOrElse("")
+
+val changeSet: ChangeSet =
+  if eventName != "pull_request" then
+    println(s"Non-PR event ($eventName), setting all categories to true")
+    ChangeSet.All
+  else
+    Env.opt(EnvNames.ChangedFilesOverride) match
+      case Some(list) =>
+        ChangeSet.Specific(splitLines(list))
+      case None =>
+        val baseRef = Env.required(EnvNames.BaseRef)
+        val result  = os.proc("git", "diff", "--name-only", s"origin/$baseRef...HEAD")
+          .call(check = false, mergeErrIntoOut = false, stderr = os.Inherit)
+        if result.exitCode != 0 then
+          System.err.println("::warning::Failed to compute diff, running all jobs")
+          println("Diff computation failed, setting all categories to true")
+          ChangeSet.All
+        else ChangeSet.Specific(splitLines(result.out.text()))
+
+val activeCategories: Set[Category] = changeSet match
+  case ChangeSet.All             => Category.values.toSet
+  case ChangeSet.Specific(files) => files.iterator.flatMap(Category.forPath).toSet
+
+println("Change categories:")
+Category.ordered.foreach(c => println(s"  ${c.key}=${activeCategories.contains(c)}"))
+
+val entries: Seq[(String, String)] =
+  Category.ordered.map(c => c.key -> activeCategories.contains(c).toString)
+
+entries.foreach((k, v) => GitHubOutput.writeScalar(k, v))
+
+Env.opt(EnvNames.ClassifyOutputFile).foreach: path =>
+  KeyValueFile.appendAll(Env.toAbsolutePath(path), entries)
+
+val categoryRows = Category.ordered
+  .map(c => s"| ${c.key} | ${activeCategories.contains(c)} |")
+  .mkString("\n")
+
+// categoryRows lines start with `|` (stripMargin's margin marker), so
+// concatenate them after the stripped template instead of interpolating.
+GitHubOutput.writeSummary(
+  s"""## Change categories
+     || Category | Changed |
+     ||----------|---------|
+     |""".stripMargin + categoryRows
+)