flatpak-builder: Add keepBuildDirs flag

Author: ranfdev

CONTRIBUTING.md

@@ -10,7 +10,8 @@ If you plan to contribute to flatpak-github-actions, here's a couple of things t
 
 For more details, we recommend looking the extensive guide at [Creating a JavaScript action](https://docs.github.com/en/actions/creating-actions/creating-a-javascript-action#prerequisites)
 
-Once you have modified the `index.js` of either `flatpak-builder` or `flat-manager` action. Make sure to compile the file to the `dist` directory. You can do so with
+Once you have modified the `index.js` of either `flatpak-builder` or `flat-manager` action, make sure to compile the file to the `dist` directory. 
+Note: You should have already installed the npm packages of both `flatpak-builder` and `flat-manager`, with yarn. 
 
 ```shell
 ncc build ./flatpak-builder/index.js -o ./flatpak-builder/dist/

README.md

@@ -59,6 +59,7 @@ jobs:
 | `build-dir` | The directory to build the application in. | Optional | `flatpak_app` |
 | `repo-dir` | The directory of the flatpak repository. | Optional | `repo` |
 | `state-dir` | The directory to store the build state/cache in. | Optional | `.flatpak-builder` |
+| `keep-build-dirs` | Keep build directories after the build finishes (passes `--keep-build-dirs` to flatpak-builder). Useful for debugging intermediate files. | Optional | `false` |
 | `verbose` | Enable verbosity | Optional | `false` |
 | `upload-artifact` | Whether to upload the resulting bundle or not as an artifact | Optional | `true` |
 

flatpak-builder/action.yml

@@ -56,6 +56,13 @@ inputs:
       Defines the cache-key to use.
       Defaults to flatpak-builder-${arch}-${sha256(manifestPath)}
     required: false
+  keep-build-dirs:
+    description: >
+      Keep build directories after the build finishes, passing `--keep-build-dirs` flag
+      to flatpak-builder.
+      Possible values: true, enabled, yes, y. Defaults to false.
+    required: false
+    default: "false"
   branch:
     description: The flatpak branch.
     default: "master"