Diff Generator Output (#662)

* 4.3 project update... apparently opening the project did this ¯\_(ツ)_/¯

* add workflow to diff generated output

* generate to /tmp

* Example generator change.

* generate to .build

* don't sandbox

* try just using build products

* don't sparse checkout since we need to switch branches

* cleaner output

* tweaked diff

* filter for changes in the generator

* use the right name for the workflow!

.github/workflows/generator.yml

@@ -0,0 +1,64 @@
+# This workflow checks to see if the Generator code has changed.
+# If it has, we run the new generator, and the version from the target branch,
+# and then we diff the two outputs.
+
+name: Generator
+
+on:
+  pull_request:
+    branches: [ "main" ]
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}-diff
+  cancel-in-progress: true
+
+jobs:
+  # JOB to run change detection
+  changes:
+    runs-on: ubuntu-latest
+    # Required permissions
+    permissions:
+      pull-requests: read
+    # Set job outputs to values from filter step
+    outputs:
+      generator: ${{ steps.filter.outputs.generator }}
+    steps:
+    # For pull requests it's not necessary to checkout the code
+    - uses: dorny/paths-filter@v3
+      id: filter
+      with:
+        filters: |
+          generator:
+            - 'Generator/**'
+
+  # JOB to run the diff - only runs if changes were detected in Generator/
+  diff-generator:
+    needs: changes
+    if: ${{ needs.changes.outputs.generator == 'true' }}
+    runs-on: macos-14
+
+    steps:
+    - name: Checkout
+      uses: actions/checkout@v4
+      with:
+        fetch-depth: 0
+    - uses: dorny/paths-filter@v3
+      id: filter
+      with:
+        filters: |
+          generator:
+            - 'Generator/**'
+    - name: Set up Xcode
+      uses: maxim-lobanov/setup-xcode@v1
+      with:
+        xcode-version: "16.2"
+    - name: Build This Branch
+      run: swift build --target SwiftGodot --scratch-path .build/New
+    - name: Checkout Target Branch
+      run: git checkout ${{ github.event.pull_request.base.sha }}
+    - name: Build Target Branch
+      run: swift build --target SwiftGodot --scratch-path .build/Old
+    - name: Diff generated
+      run: diff --recursive --color=auto --minimal .build/New/plugins/outputs/swiftgodot/SwiftGodot/destination/CodeGeneratorPlugin/ .build/Old/plugins/outputs/swiftgodot/SwiftGodot/destination/CodeGeneratorPlugin/ | sed -e 's/diff\(.*\)\/\(.*\).swift/\n\2.swift:/'
+
+

Generator/Generator/Printer.swift

@@ -26,7 +26,7 @@ class Printer {
 
     fileprivate static let preamble =
         """
-        // This file is autogenerated, do not edit
+        // This file is auto-generated, do not edit.
         @_implementationOnly import GDExtension
 
         #if CUSTOM_BUILTIN_IMPLEMENTATIONS

Testbed/project.godot

@@ -12,7 +12,7 @@ config_version=5
 
 config/name="GDExtension Test Project"
 run/main_scene="res://main.tscn"
-config/features=PackedStringArray("4.1")
+config/features=PackedStringArray("4.3")
 config/icon="res://icon.png"
 
 [native_extensions]