Allow validating the extension api against a reference version and a list of known changes.

misc/scripts/validate_extension_api.sh

@@ -0,0 +1,60 @@
+#!/bin/bash
+set -uo pipefail
+
+if [ ! -f "version.py" ]; then
+  echo "Warning: This script is intended to be run from the root of the Godot repository."
+  echo "Some of the paths checks may not work as intended from a different folder."
+fi
+
+if [ $# != 1 ]; then
+  echo "Usage: @0 <path-to-godot-executable>"
+fi
+
+has_problems=0
+
+make_annotation()
+{
+  local title=$1
+  local body=$2
+  local type=$3
+  local file=$4
+  if [ ! -v GITHUB_OUTPUT ]; then
+    echo "$title"
+    echo "$body"
+  else
+    body="$(awk 1 ORS='%0A' - <<<"$body")"
+    echo "::$type file=$file,title=$title ::$body"
+  fi
+}
+
+while read -r file; do
+    reference_file="$(mktemp)"
+    validate="$(mktemp)"
+    validation_output="$(mktemp)"
+    allowed_errors="$(mktemp)"
+
+    # Download the reference extension_api.json
+    reference_tag="$(basename -s .expected "$file")"
+    wget -qcO "$reference_file" "https://raw.githubusercontent.com/godotengine/godot-cpp/godot-$reference_tag/gdextension/extension_api.json"
+    # Validate the current API against the reference
+    "$1" --headless --validate-extension-api "$reference_file" 2>&1 | tee "$validate" | awk '!/^Validate extension JSON:/' - || true
+    # Collect the expected and actual validation errors
+    awk '/^Validate extension JSON:/' - < "$validate" | sort > "$validation_output"
+    awk '/^Validate extension JSON:/' - < "$file" | sort > "$allowed_errors"
+
+    # Differences between the expected and actual errors
+    new_validation_error="$(comm "$validation_output" "$allowed_errors" -23)"
+    obsolete_validation_error="$(comm "$validation_output" "$allowed_errors" -13)"
+
+    if [ -n "$obsolete_validation_error" ]; then
+        make_annotation "The following validation errors no longer occur (compared to $reference_tag):" "$obsolete_validation_error" warning "$file"
+    fi
+    if [ -n "$new_validation_error" ]; then
+        make_annotation "Compatibility to $reference_tag is broken in the following ways:" "$new_validation_error" error README.md
+        has_problems=1
+    fi
+
+    rm -f "$reference_file" "$validate" "$validation_output" "$allowed_errors"
+done <<< "$(find "$( dirname -- "$( dirname -- "${BASH_SOURCE[0]//\.\//}" )" )/extension_api_validation/" -name "*.expected")"
+
+exit $has_problems