Write error log to GitHub Actions variable error_log (for use with PR comments)

Author: rbob86

action.yml

@@ -4,19 +4,24 @@ description: Lint LookML Projects and create Pull Request reviews with linting v
 
 inputs:
   configFile:
-    description: 'path to config file'
-    required: true
+    description: 'Path to linter config file specifying severity of each rule.'
+    required: false
     default: ${{ github.workspace }}/.github/config.yaml
   filepaths:
-    description: 'list of files to lint (using output of tj-actions/changed-files action in workflow)'
+    description: 'List of files to lint. Ignore if wanting to lint ALL project files. Use output from tj-actions/changed-files action in workflow to lint only files changed in commit/pull request.'
     required: false
     default: null
   saveOutputToFile:
-    description: 'Flag to determine whether or not linter output should be saved to a .txt file within repo'
+    description: 'Flag to determine whether or not linter output should be saved to a .txt file within repo.'
     required: false
     default: false
     type: boolean
 
+outputs:
+  error_log:
+    description: 'Error/warning output generated by the linter (indented by LookML file names).'
+    value: ${{ steps.lookml-linter.outputs.error_log }}
+
 runs:
   using: docker
   image: Dockerfile

linter/main.py

@@ -1,4 +1,5 @@
 import os
+import subprocess
 from linter.config_validator import ConfigValidator
 from linter.lookml_linter import LookMlLinter
 from linter.lookml_project_parser import LookMlProjectParser
@@ -27,6 +28,13 @@ def main():
         error_log = linter.get_errors()
         print(error_log)
 
+        # Save output to GHA environment variable
+        with open(os.getenv('GITHUB_ENV'), 'a') as fh:
+            error_log = error_log.replace('    ', '    ')
+            fh.write("error_log<<EOF\n")
+            fh.write(error_log)
+            fh.write("EOF\n")
+        
         # Save output to file, if enabled
         if save_output_to_file == 'true' or save_output_to_file == 'True':
             linter.save_errors(error_log, '_lookml-linter-output.txt')