builder API; move override logic into produceDerivation

This should simplify writing builders

src/builders/nodejs/granular/default.nix

@@ -32,10 +32,11 @@
   # where versions is a list of version strings
   packageVersions,
 
-  # Overrides
-  # Those must be applied by the builder to each individual derivation
-  # using `utils.applyOverridesToPackage`
-  packageOverrides ? {},
+  # function which applies overrides to a package
+  # It must be applied by the builder to each individual derivation
+  # Example:
+  #   produceDerivation name (mkDerivation {...})
+  produceDerivation,
 
   # Custom Options: (parametrize builder behavior)
   # These can be passed by the user via `builderArgs`.
@@ -70,6 +71,10 @@ let
               makePackage name version))
       packageVersions;
 
+  outputs = {
+    inherit defaultPackage packages;
+  };
+
   # Generates a derivation for a specific package name + version
   makePackage = name: version:
     let
@@ -88,7 +93,7 @@ let
             deps));
 
       pkg =
-        stdenv.mkDerivation rec {
+        produceDerivation name (stdenv.mkDerivation rec {
 
           packageName = name;
         
@@ -300,13 +305,16 @@ let
               done
             fi
           '';
-        };
+        });
     in
+      pkg;
       # apply packageOverrides to current derivation
-      (utils.applyOverridesToPackage packageOverrides pkg name);
-
+      # (utils.applyOverridesToPackage {
+      #   inherit outputs pkg;
+      #   conditionalOverrides = packageOverrides;
+      #   pname = name;
+      # });
 
 in
-{
-  inherit defaultPackage packages;
-}
+outputs
+

src/default.nix

@@ -229,6 +229,7 @@ let
       dreamLock,
       inject,
       sourceOverrides,
+      packageOverrides,
     }@args:
       let
 
@@ -242,6 +243,14 @@ let
         fetchedSources =
           args.fetchedSources // changedSources;
 
+        produceDerivation = name: pkg:
+          utils.applyOverridesToPackage {
+            inherit pkg;
+            packages = formattedOutputs.packages;
+            pname = name;
+            conditionalOverrides = packageOverrides;
+          };
+
         buildPackageWithOtherBuilder =
           {
             builder,
@@ -258,16 +267,24 @@ let
 
           in
             callBuilder {
-              inherit builder builderArgs inject sourceOverrides;
+              inherit
+                builder
+                builderArgs
+                fetchedSources
+                inject
+                sourceOverrides
+                packageOverrides
+              ;
+
               dreamLock =
                 subDreamLockLoaded.lock;
-              inherit fetchedSources;
             };
 
         outputs = builder ( builderArgs // {
 
           inherit
             buildPackageWithOtherBuilder
+            produceDerivation
           ;
 
           inherit (dreamLockInterface)
@@ -283,8 +300,33 @@ let
 
         });
 
+        # Makes the packages tree compatible with flakes schema.
+        # For each package the attr `{pname}` will link to the latest release.
+        # Other package versions will be inside: `{pname}.versions`
+        formattedOutputs = outputs // {
+          packages =
+            let
+              allPackages = outputs.packages or {};
+
+              latestPackages =
+                lib.mapAttrs'
+                  (pname: releases:
+                    let
+                      latest =
+                        releases."${utils.latestVersion (b.attrNames releases)}";
+                    in
+                      (lib.nameValuePair
+                        "${pname}"
+                        (latest // {
+                          versions = releases;
+                        })))
+                  allPackages;
+            in
+              latestPackages;
+        };
+
       in
-        outputs;
+        formattedOutputs;
 
 
   # produce outputs for a dream-lock or a source
@@ -339,48 +381,28 @@ let
       }).fetchedSources;
 
       builderOutputs = callBuilder {
+
         inherit
           dreamLock
           fetchedSources
           sourceOverrides
         ;
+
         builder = builder';
-        builderArgs = (args.builderArgs or {}) // {
-          packageOverrides =
-            lib.recursiveUpdate
-              (dreamOverrides."${dreamLock._generic.subsystem}" or {})
-              (args.packageOverrides or {});
-        };
+
+        inherit builderArgs;
+
+        packageOverrides =
+          lib.recursiveUpdate
+            (dreamOverrides."${dreamLock._generic.subsystem}" or {})
+            (args.packageOverrides or {});
+
         inject =
           utils.dreamLock.decompressDependencyGraph args.inject or {};
       };
 
-      # Makes the packages tree compatible with flakes schema.
-      # For each package the attr `{pname}` will link to the latest release.
-      # Other package versions will be inside: `{pname}.versions`
-      formattedBuilderOutputs = builderOutputs // {
-        packages =
-          let
-            allPackages = builderOutputs.packages or {};
-
-            latestPackages =
-              lib.mapAttrs'
-                (pname: releases:
-                  let
-                    latest =
-                      releases."${utils.latestVersion (b.attrNames releases)}";
-                  in
-                    (lib.nameValuePair
-                      "${pname}"
-                      (latest // {
-                        versions = releases;
-                      })))
-                allPackages;
-          in
-            latestPackages;
-      };
     in
-      formattedBuilderOutputs;
+      builderOutputs;
    
 in
 {

src/templates/builders/default.nix

@@ -28,10 +28,11 @@
   # where versions is a list of version strings
   packageVersions,
 
-  # Overrides
-  # Those must be applied by the builder to each individual derivation
-  # using `utils.applyOverridesToPackage`
-  packageOverrides ? {},
+  # function which applies overrides to a package
+  # It must be applied by the builder to each individual derivation
+  # Example:
+  #   produceDerivation name (mkDerivation {...})
+  produceDerivation,
 
   # Custom Options: (parametrize builder behavior)
   # These can be passed by the user via `builderArgs`.

src/utils/override.nix

@@ -54,19 +54,32 @@ let
       ```
     '';
 
-  applyOverridesToPackage = conditionalOverrides: pkg: pname:
-    # if ! conditionalOverrides ? "${pname}" then
-    #   pkg
-    # else
-      
+  getOverrideFunctionArgs = function:
+    let
+      funcArgs = lib.functionArgs function;
+    in
+      if funcArgs != {} then
+        b.attrNames funcArgs
+      else
+        (
+          function (old: {passthru.funcArgs = lib.attrNames old;})
+        ).funcArgs;
+
+  applyOverridesToPackage =
+    {
+      conditionalOverrides,
+      pkg,
+      pname,
+      packages,
+    }:
       let
 
         # if condition is unset, it will be assumed true
         evalCondition = condOverride: pkg:
-            if condOverride ? _condition then
-              condOverride._condition pkg
-            else
-              true;
+          if condOverride ? _condition then
+            condOverride._condition pkg
+          else
+            true;
 
         # filter the overrides by the package name and conditions
         overridesToApply =
@@ -88,7 +101,9 @@ let
 
             overridesListForPackage =
               lib.mapAttrsToList
-                (_name: data: data // { inherit _name; })
+                (_name: data:
+                  data // { inherit _name; }
+                )
                 overridesForPackage;
           in
             (lib.filter
@@ -97,10 +112,10 @@ let
 
         # apply single attribute override
         applySingleAttributeOverride = oldVal: functionOrValue:
-           if b.isFunction functionOrValue then
-              functionOrValue oldVal
-            else
-              functionOrValue;
+          if b.isFunction functionOrValue then
+            functionOrValue oldVal
+          else
+            functionOrValue;
 
         # helper to apply one conditional override
         # the condition is not evaluated anymore here
@@ -128,7 +143,7 @@ let
               let
                 availableFunctions =
                   lib.mapAttrs
-                    (funcName: func: lib.attrNames (lib.functionArgs func))
+                    (funcName: func: getOverrideFunctionArgs func)
                     (lib.filterAttrs
                       (funcName: func: lib.hasPrefix "override" funcName)
                       base_derivation);
@@ -143,8 +158,8 @@ let
                   in
                     if b.length applicableFuncs == 0 then
                       "overrideAttrs"
-                    else if b.length applicableFuncs >= 1 then
-                      throwErrorUnclearAttributeOverride pname condOverride._name attrName
+                    else if b.length applicableFuncs > 1 then
+                      throwErrorUnclearAttributeOverride Hpname condOverride._name attrName
                     else
                       b.elemAt applicableFuncs 0;
 
@@ -175,12 +190,12 @@ let
                       updateAttrsFuncs))
               base_derivation
               (overrideFuncs ++ singleArgOverrideFuncs);
-      in
-        # apply the overrides to the given pkg
-        (lib.foldl
-          (pkg: condOverride: applyOneOverride pkg condOverride)
-          pkg
-          overridesToApply);
+        in
+          # apply the overrides to the given pkg
+          (lib.foldl
+            (pkg: condOverride: applyOneOverride pkg condOverride)
+            pkg
+            overridesToApply);
 
 in
 {