fix: generate sql migrations for tag versions

Author: samrose

nix/ext/pg_graphql.nix

@@ -12,6 +12,17 @@ buildPgrxExtension_0_11_3 rec {
     hash = "sha256-Q6XfcTKVOjo5pGy8QACc4QCHolKxEGU8e0TTC6Zg8go=";
   };
 
+  # update the following array when the pg_graphql version is updated
+  # required to ensure that extensions update scripts from previous versions are generated
+  previousVersions = [
+    "1.5.6" "1.5.5" "1.5.4" "1.5.3" "1.5.2" "1.5.1" "1.5.0" 
+    "1.4.4" "1.4.3" "1.4.2" "1.4.1" "1.4.0" "1.3.0" "1.2.3" "1.2.2" 
+    "1.2.1" "1.2.0" "1.1.0" "1.0.2" "1.0.1" "1.0.0" "0.5.3" 
+    "0.5.2" "0.5.0" "0.4.1" "0.4.0" "0.3.3" "0.3.2" "0.3.1" 
+    "0.3.0" "0.2.1" "0.2.0"  "0.1.5" "0.1.4" "0.1.3" "0.1.2" 
+    "0.1.1" "0.1.0"
+    ];
+
   nativeBuildInputs = [ cargo ];
   buildInputs = [ postgresql ];
 
@@ -27,6 +38,30 @@ buildPgrxExtension_0_11_3 rec {
   # to work, though
   doCheck = false;
 
+  preBuild = ''
+    echo "Processing git tags..."
+    echo '${builtins.concatStringsSep "," previousVersions}' | sed 's/,/\n/g' > git_tags.txt
+  '';
+
+  postInstall = ''
+    echo "Creating SQL files for previous versions..."
+    current_version="${version}"
+    sql_file="$out/share/postgresql/extension/pg_graphql--$current_version.sql"
+    
+    if [ -f "$sql_file" ]; then
+      while read -r previous_version; do
+        if [ "$(printf '%s\n' "$previous_version" "$current_version" | sort -V | head -n1)" = "$previous_version" ] && [ "$previous_version" != "$current_version" ]; then
+          new_file="$out/share/postgresql/extension/pg_graphql--$previous_version--$current_version.sql"
+          echo "Creating $new_file"
+          cp "$sql_file" "$new_file"
+        fi
+      done < git_tags.txt
+    else
+      echo "Warning: $sql_file not found"
+    fi
+    rm git_tags.txt
+  '';
+
   meta = with lib; {
     description = "GraphQL support for PostreSQL";
     homepage = "https://github.com/supabase/${pname}";