Use a problem matcher

.github/markdownlint-problem-matcher.json

@@ -0,0 +1,16 @@
+{
+  "problemMatcher": [
+    {
+      "owner": "markdownlint",
+      "pattern": [
+        {
+          "code": 3,
+          "file": 1,
+          "line": 2,
+          "message": 4,
+          "regexp": "^(.+):(\\d+)(?:\\d+)? (\\S+) (.+)$"
+        }
+      ]
+    }
+  ]
+}

.github/workflows/ci.yml

@@ -26,15 +26,30 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v2.4.0
-      - uses: ./
+      - name: Test problem matcher
+        id: expect-failure
+        uses: ./
+        with:
+          config_file: .markdownlintrc
+          files: .
+          rules: examples/rules/custom.js
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        continue-on-error: true
+      - if: ${{ steps.expect-failure.outcome != 'failure' }}
+        run: |
+          exit 1
+      - name: Test ignore_files
+        uses: ./
         with:
           config_file: .markdownlintrc
           files: .
           ignore_files: examples/ignore/*
           rules: examples/rules/custom.js
         env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
-      - uses: ./
+      - name: Test ignore_path
+        uses: ./
         with:
           config_file: .markdownlintrc
           files: .

entrypoint.sh

@@ -6,41 +6,12 @@ MARKDOWNLINT="${MARKDOWNLINT}${INPUT_IGNORE_FILES:+ -i ${INPUT_IGNORE_FILES}}"
 MARKDOWNLINT="${MARKDOWNLINT}${INPUT_IGNORE_PATH:+ -p ${INPUT_IGNORE_PATH}}"
 MARKDOWNLINT="${MARKDOWNLINT}${INPUT_RULES:+ -r ${INPUT_RULES}}"
 
-# shellcheck disable=SC2086
-OUTPUT=$(${MARKDOWNLINT} ${INPUT_FILES} 2>&1)
-SUCCESS=$?
-echo "${OUTPUT}"
-
-if [ ${SUCCESS} -eq 0 ]; then
-  exit 0
-fi
-
-if [ "${GITHUB_EVENT_NAME}" = pull_request ]; then
-  comment=""
-  FILES=$(echo "${OUTPUT}" | cut -d: -f1 | sort | uniq)
-
-  for file in ${FILES}; do
-    comment="${comment}<details><summary><code>${file}</code></summary>
+echo '::add-matcher::.github/markdownlint-problem-matcher.json'
 
-\`\`\`
-$(echo "${OUTPUT}" | grep "^${file}:" | sed "s/^[^:]*:[[:space:]]*//")
-\`\`\`
-
-</details>"
-  done
-
-  COMMENT_BODY="#### Issues with Markdown/CommonMark files
-${comment}
-
-*Workflow: \`${GITHUB_WORKFLOW}\`, Action: \`${GITHUB_ACTION}\`*"
-  PAYLOAD=$(echo '{}' | jq --arg body "${COMMENT_BODY}" '.body = $body')
-  COMMENTS_URL=$(jq -r .pull_request.comments_url <"${GITHUB_EVENT_PATH}")
+# shellcheck disable=SC2086
+${MARKDOWNLINT} ${INPUT_FILES}
+readonly RC=$?
 
-  curl -sS \
-    -H "Authorization: token ${GITHUB_TOKEN}" \
-    -H 'Content-Type: application/json' \
-    -d "${PAYLOAD}" \
-    "${COMMENTS_URL}" >/dev/null
-fi
+echo '::remove-matcher owner=markdownlint::'
 
-exit ${SUCCESS}
+exit ${RC}