Add warnings-as-errors option

Author: Joseph-Edwards

Diff for: README.md

@@ -20,6 +20,9 @@ All of the following inputs are optional.
 - `GAP_TESTFILE`:
   - The name of the GAP file to be read for executing the package tests.
   - default: `'tst/testall.g'`
+- `warnings-as-errors`:
+  - Set to `true` to treat warnings produced when loading the package as errors.
+  - default: `false`
 
 ### Example
 
@@ -46,10 +49,12 @@ jobs:
 ```
 
 ## Contact
+
 Please submit bug reports, suggestions for improvements and patches via
 the [issue tracker](https://github.com/gap-actions/run-pkg-tests/issues).
 
 ## License
+
 The action `run-pkg-tests` is free software; you can redistribute
 and/or modify it under the terms of the GNU General Public License as published
 by the Free Software Foundation; either version 2 of the License, or (at your

Diff for: action.yml

@@ -16,6 +16,11 @@ inputs:
     required: false
     type: boolean
     default: false
+  warnings-as-errors:
+    description: 'If set to true then any errors produced whilst loading the package will be treated as errors'
+    required: false
+    type: boolean
+    default: false
 env:
   CHERE_INVOKING: 1
 
@@ -59,14 +64,33 @@ runs:
          if IsEmpty(GAP_TESTFILE) or not IsExistingFile(GAP_TESTFILE) then
              GAP_TESTFILE := info.TestFile;
          fi;
-         # Load the package with debug info
+
          SetInfoLevel(InfoPackageLoading, PACKAGE_DEBUG);
          SetPackagePath(info.PackageName, "/tmp/gaproot/pkg/$(basename $PWD)");
+
+         # Capture the output of loading
+         output := "";
+         output_stream := OutputTextString(output, true);
+         SetPrintFormattingStatus(output_stream, false);
+         OutputLogTo(output_stream);
+
+         # Load the package with debug info
          if ${{ inputs.only-needed }} = true then
             LoadPackage(info.PackageName : OnlyNeeded);
          else
             LoadPackage(info.PackageName);
          fi;
+
+         OutputLogTo();
+         CloseStream(output_stream);
+
+         # Treat warnings as errors if specified
+         if ${{ inputs.warnings-as-errors }} = 'true' ; then
+            if PositionSublist(output, "warning") <> fail then
+                Error("Warnings were found when loading the package");
+            fi;
+         fi;
+
          SetInfoLevel(InfoPackageLoading, PACKAGE_ERROR);
          Print("Now running tests from ", GAP_TESTFILE, "\n");
          if EndsWith(GAP_TESTFILE, ".tst") then