npins: restore asFlake patch

npins/default.nix

@@ -112,7 +112,18 @@ let
         else
           builtins.throw "Unknown source type ${spec.type}";
     in
-    spec // { outPath = mayOverride name path; };
+    spec
+    // rec {
+      outPath = mayOverride name path;
+
+      # Waiting for discussion upstream
+      # https://github.com/andir/npins/issues/159
+      asFlake =
+        if sources ? flake-compat then
+          (import sources.flake-compat { src = outPath; }).outputs
+        else
+          throw ".asFlake needs flake-compat as a source";
+    };
 
   mkGitSource =
     {
@@ -221,29 +232,31 @@ let
         imageDigest = image_digest;
         finalImageTag = image_tag;
       };
-in
-mkFunctor (
-  {
-    input ? ./sources.json,
-  }:
-  let
-    data =
-      if builtins.isPath input then
-        # while `readFile` will throw an error anyways if the path doesn't exist,
-        # we still need to check beforehand because *our* error can be caught but not the one from the builtin
-        # *piegames sighs*
-        if builtins.pathExists input then
-          builtins.fromJSON (builtins.readFile input)
+
+  sources = mkFunctor (
+    {
+      input ? ./sources.json,
+    }:
+    let
+      data =
+        if builtins.isPath input then
+          # while `readFile` will throw an error anyways if the path doesn't exist,
+          # we still need to check beforehand because *our* error can be caught but not the one from the builtin
+          # *piegames sighs*
+          if builtins.pathExists input then
+            builtins.fromJSON (builtins.readFile input)
+          else
+            throw "Input path ${toString input} does not exist"
+        else if builtins.isAttrs input then
+          input
         else
-          throw "Input path ${toString input} does not exist"
-      else if builtins.isAttrs input then
-        input
-      else
-        throw "Unsupported input type ${builtins.typeOf input}, must be a path or an attrset";
-    version = data.version;
-  in
-  if version == 7 then
-    builtins.mapAttrs (name: spec: mkFunctor (mkSource name spec)) data.pins
-  else
-    throw "Unsupported format version ${toString version} in sources.json. Try running `npins upgrade`"
-)
+          throw "Unsupported input type ${builtins.typeOf input}, must be a path or an attrset";
+      version = data.version;
+    in
+    if version == 7 then
+      builtins.mapAttrs (name: spec: mkFunctor (mkSource name spec)) data.pins
+    else
+      throw "Unsupported format version ${toString version} in sources.json. Try running `npins upgrade`"
+  );
+in
+sources