Validate API reports are up-to-date in CI

Author: japgolly

.github/workflows/ci.yml

@@ -21,20 +21,28 @@ jobs:
     env:
       SCALAJS_VERSION: "${{ matrix.scalajsversion == '0.6.x' && '0.6.28' || '' }}"
     steps:
+
       - uses: actions/checkout@v2
       - uses: olafurpg/setup-scala@v13
         with:
           java-version: "adopt@1.8"
       - uses: coursier/cache-action@v6
+
       - name: Build
         run: sbt "++${{ matrix.scalaversion }}" package
+
       - name: Test generate documentation
         run: sbt "++${{ matrix.scalaversion }}" doc
+
       - name: Build examples
         run: sbt "++${{ matrix.scalaversion }}" example/compile
-      - name: scalafmt
+
+      - name: Validate formatting
         run: sbt "++${{ matrix.scalaversion }}" scalafmtCheck
 
+      - name: Validate api report
+        run: ./api-reports/validate "${{ matrix.scalaversion }}"
+
   readme:
     runs-on: ubuntu-latest
     steps:

api-2_12.txt renamed to api-reports/2_12.txt

@@ -0,0 +1,21 @@
+#!/bin/bash
+set -euo pipefail
+cd "$(dirname "$0")"
+
+[ $# -ne 1 ] && echo "Usage: $0 <scala version>" && exit 1
+
+series="${1%.*}"
+file="${series/./_}.txt"
+echo -n "Validating $file ... "
+
+help='Run `sbt +compile` and check in the differences to the '"$(basename "$0") directory"
+
+if [ ! -e "$file" ]; then
+  echo "file not found. $help"
+  exit 2
+elif [ -n "$(git status --porcelain -- "$file")" ]; then
+  echo "out-of-date. $help"
+  exit 3
+else
+  echo "ok"
+fi

api-2_13.txt renamed to api-reports/2_13.txt

@@ -100,7 +100,7 @@ class GenerateApiReport extends SemanticRule("GenerateApiReport") {
   private def saveReport(): Unit = {
     val scalaVer    = Util.scalaSeriesVer.replace('.', '_')
     val projectRoot = System.getProperty("user.dir")
-    val reportFile  = Paths.get(s"$projectRoot/api-$scalaVer.txt")
+    val reportFile  = Paths.get(s"$projectRoot/api-reports/$scalaVer.txt")
     val api         = state.result().iterator.map(_.stripPrefix("org/scalajs/dom/")).mkString("\n")
 
     val content =