Use strings as default input values

action.yml

@@ -7,23 +7,23 @@ inputs:
   source_directory:
     description: Directory where Debian sources are, relative to workspace
     required: false
-    default: ./
+    default: "./"
   artifacts_directory:
     description: Directory where build artifacts will be placed, relative to workspace
     required: false
-    default: ./
+    default: "./"
   target_architectures:
     description: Target architecture of Debian package to build
     required: false
-    default: []
+    default: ""
   dpkg_buildpackage_opts:
     description: Options list provided to 'dpkg-buildpackage' as command line parameters (note that '-a' is automatically provided for target architectures specified by target_architectures)
     required: false
-    default: [ "--no-sign", "-d" ]
+    default: "--no-sign, -d"
   lintian_opts:
     description: Options list provided to 'lintian' as command line parameters
     required: false
-    default: []
+    default: ""
 
 runs:
   using: node12

main.js

@@ -35,7 +35,7 @@ async function main() {
             // (Seems to not recognize that some packages are installed)
             "-d"
         ]
-        const dpkgBuildPackageOpts = core.getInput("dpkg_buildpackage_opts") || defaultDpkgBuildPackageOpts
+        const dpkgBuildPackageOpts = core.getInput("dpkg_buildpackage_opts").replaceAll(" ", "").split(",") || defaultDpkgBuildPackageOpts
         const lintianOpts = core.getInput("lintian_opts") || []
 
         const workspaceDirectory = process.cwd()