feat: Autodetect extensions from composer.json.

flake.nix

@@ -16,6 +16,19 @@
             config = { allowUnfree = true; };
           };
 
+          # Get composer file into set
+          composer = builtins.fromJSON (builtins.readFile "${builtins.getEnv "PWD"}/composer.json");
+          # Get "require" section
+          require = (if (composer ? require) then composer.require else {});
+          # Copy the keys of a set in a value
+          exts = nixpkgs.lib.attrsets.mapAttrs' (name: value: nixpkgs.lib.nameValuePair name name) require;
+          # Convert the set into a list
+          exts2 = (map (key: builtins.getAttr key exts) (builtins.attrNames exts));
+          # Filter out values not starting with "ext-"
+          exts3 = builtins.filter (x: (builtins.substring 0 4 x) == "ext-") exts2;
+          # Get rid of the first 4 characters in the name
+          userExtensions = map (x: builtins.substring 4 (builtins.stringLength x) x) exts3;
+
           extensionsGroups = {
             mandatory = [
               "bcmath"
@@ -30,7 +43,7 @@
               "posix"
               "intl"
               "opcache"
-            ];
+            ] ++ userExtensions;
 
             optional = [
               "calendar"