Add failIfEmpty argument (fixes #84) (#86)

* Add fail if empty argument

If no links were found during a run, this could indicate a configuration
issue. In order to warn users, this new option allows failing the pipeline
in such a scenario.

.github/workflows/test.yml

@@ -1,18 +1,19 @@
 on:
-  - repository_dispatch
-  - workflow_dispatch
-  - push
-  - pull_request
+  push:
+    branches:
+      - master
+  pull_request:
+  workflow_dispatch:
+  repository_dispatch:
 
 env:
   CUSTOM_OUTPUT_RELATIVE_PATH: lychee/custom_output.md
   CUSTOM_OUTPUT_ABSOLUTE_PATH: /tmp/report.md
   CUSTOM_OUTPUT_DUMP_PATH: /tmp/dump.md
-    
+
 jobs:
   lychee-action:
     runs-on: ubuntu-latest
-    continue-on-error: true
     name: Test the lychee link checker action
     steps:
       - name: Checkout
@@ -57,7 +58,7 @@ jobs:
         with:
           output: "${{ env.CUSTOM_OUTPUT_RELATIVE_PATH }}"
           debug: true
-          
+
       - name: test custom output relative path - validation
         run: |
           echo "Checking custom output file at ${{ env.CUSTOM_OUTPUT_RELATIVE_PATH }}"
@@ -68,13 +69,13 @@ jobs:
             echo "Found. Contents:"
             cat "${{ env.CUSTOM_OUTPUT_RELATIVE_PATH }}"
           fi
-         
+
       - name: test custom output absolute path - creation
         uses: ./
         with:
           output: "${{ env.CUSTOM_OUTPUT_ABSOLUTE_PATH }}"
           debug: true
-          
+
       - name: test custom output absolute path - validation
         run: |
           echo "Checking custom output file at ${{ env.CUSTOM_OUTPUT_ABSOLUTE_PATH }}"
@@ -92,7 +93,7 @@ jobs:
           args: --dump './**/*.md' './**/*.html' './**/*.rst'
           output: "${{ env.CUSTOM_OUTPUT_DUMP_PATH }}"
           debug: true
-          
+
       - name: test dump with custom output path - validation
         run: |
           echo "Checking dump output file at ${{ env.CUSTOM_OUTPUT_DUMP_PATH }}"
@@ -104,6 +105,28 @@ jobs:
             cat "${{ env.CUSTOM_OUTPUT_DUMP_PATH }}"
           fi
 
+      - name: test failIfEmpty - no links in input should fail the pipeline
+        id: fail_if_empty_test
+        uses: ./
+        with:
+          args: --verbose --no-progress fixtures/empty.md
+          debug: true
+        continue-on-error: true
+
+      # Explictly check the exit code of the previous step
+      # as it's expected to fail
+      - name: Check failIfEmpty
+        if: steps.fail_if_empty_test.outcome != 'failure'
+        run: |
+          echo "FailIfEmpty should have failed because no links were found."
+          exit 1
+
+      - name: test disable failIfEmpty - it's okay if no links are found
+        uses: ./
+        with:
+          args: --no-progress fixtures/empty.md
+          failIfEmpty: false
+
       - name: Install jq
         run: sudo apt-get install jq
 

action.yml

@@ -13,6 +13,10 @@ inputs:
     description: "Fail entire pipeline on error (i.e. when lychee exit code is not 0)"
     default: false
     required: false
+  failIfEmpty:
+    description: "Fail entire pipeline if no links were found"
+    default: true
+    required: false
   format:
     description: "Summary output format (e.g. json)"
     default: "markdown"
@@ -30,7 +34,7 @@ inputs:
     default: "lychee/out.md"
     required: false
   token:
-    description: 'Your GitHub Access Token, defaults to: {{ github.token }}'
+    description: "Your GitHub Access Token, defaults to: {{ github.token }}"
     default: ${{ github.token }}
     required: false
 outputs:
@@ -60,6 +64,7 @@ runs:
         INPUT_ARGS: ${{ inputs.ARGS }}
         INPUT_DEBUG: ${{ inputs.DEBUG }}
         INPUT_FAIL: ${{ inputs.FAIL }}
+        INPUT_FAILIFEMPTY: ${{ inputs.FAILIFEMPTY }}
         INPUT_FORMAT: ${{ inputs.FORMAT }}
         INPUT_JOBSUMMARY: ${{ inputs.JOBSUMMARY }}
         INPUT_OUTPUT: ${{ inputs.OUTPUT }}

entrypoint.sh

@@ -25,6 +25,20 @@ FORMAT=""
 eval lychee ${FORMAT} --output ${LYCHEE_TMP} ${ARGS} 
 exit_code=$?
 
+# Overwrite the exit code in case no links were found
+# and `fail-if-empty` is set to `true` (and it is by default)
+if [ "${INPUT_FAILIFEMPTY}" = "true" ]; then
+    # Explicitly set INPUT_FAIL to true to ensure the script fails
+    # if no links are found
+    INPUT_FAIL=true
+    # This is a somewhat crude way to check the Markdown output of lychee
+    if grep -E 'Total\s+\|\s+0' "${LYCHEE_TMP}"; then
+        echo "No links were found. This usually indicates a configuration error." >> "${LYCHEE_TMP}"
+        echo "If this was expected, set 'fail-if-empty: false' in the args." >> "${LYCHEE_TMP}"
+        exit_code=1
+    fi
+fi
+
 if [ ! -f "${LYCHEE_TMP}" ]; then
     echo "No output. Check pipeline run to see if lychee panicked." > "${LYCHEE_TMP}"
 else

fixtures/empty.md

@@ -0,0 +1 @@
+This file contains no links. Used for checking `failIfEmpty` flag.