flake.nix: expose library as an overlay

t184256 · May 18, 2023 · f0acee7 · f0acee7
1 parent 0081cb9
commit f0acee7
Showing 1 changed file with 52 additions and 33 deletions.
diff --git a/flake.nix b/flake.nix
@@ -7,58 +7,77 @@
   outputs = { self, nixpkgs, flake-utils }:
     flake-utils.lib.eachDefaultSystem (system:
       let
-        pkgs = nixpkgs.legacyPackages.${system};
-        python3Packages = pkgs.python311Packages;  # force 3.11+
-        pylama = python3Packages.pylama.overridePythonAttrs (_: {
-          # https://github.com/klen/pylama/issues/232
-          patches = [
-            (pkgs.fetchpatch {
-              url = "https://github.com/klen/pylama/pull/233.patch";
-              hash = "sha256-jaVG/vuhkPiHEL+28Pf1VuClBVlFtlzDohT0mZasL04=";
-            })
-          ];
-        });
-        pytest-asyncio =
-          python3Packages.pytest-asyncio.overridePythonAttrs rec {
-            pname = "pytest-asyncio";
-            version = "0.21.0";  # first one with typing
-            src = pkgs.fetchPypi {
-              inherit pname version;
-              sha256 = "sha256-Kziklq71b1aw6HVX7DE+EeGrknb8OGP2p74PHQ5BXhs=";
-            };
-          };
         deps = pyPackages: with pyPackages; [
           sqlalchemy aiosqlite
         ];
-        tools = pkgs: pyPackages: (with pyPackages; [
+        tools = pyPackages: (with pyPackages; [
           pytest pytestCheckHook
           coverage pytest-cov
           mypy pytest-mypy
-          pylama pyflakes pycodestyle pydocstyle mccabe pylint
+          (pylama' pyPackages)
+          pyflakes pycodestyle pydocstyle mccabe pylint
           eradicate
-          pytest-asyncio
+          (pytest-asyncio' pyPackages)
         ]);
 
-        asyncdbview = python3Packages.buildPythonPackage {
-          pname = "asyncdbview";
-          version = "0.0.1";
-          src = ./.;
-          format = "pyproject";
-          propagatedBuildInputs = deps python3Packages;
-          nativeBuildInputs = [ python3Packages.setuptools ];
-          checkInputs = tools pkgs python3Packages;
+        pylama' = pyPackages:
+          pyPackages.pylama.overridePythonAttrs (_: {
+            # https://github.com/klen/pylama/issues/232
+            patches = [
+              (pkgs.fetchpatch {
+                url = "https://github.com/klen/pylama/pull/233.patch";
+                hash = "sha256-jaVG/vuhkPiHEL+28Pf1VuClBVlFtlzDohT0mZasL04=";
+              })
+            ];
+          });
+        pytest-asyncio' = pyPackages:
+          pyPackages.pytest-asyncio.overridePythonAttrs rec {
+            pname = "pytest-asyncio";
+            version = "0.21.0";  # first one with typing
+            src = pyPackages.fetchPypi {
+              inherit pname version;
+              sha256 = "sha256-Kziklq71b1aw6HVX7DE+EeGrknb8OGP2p74PHQ5BXhs=";
+            };
+          };
+
+        asyncdbview-package = {python3Packages}:
+          python3Packages.buildPythonPackage {
+            pname = "asyncdbview";
+            version = "0.0.1";
+            src = ./.;
+            format = "pyproject";
+            propagatedBuildInputs = deps python3Packages;
+            nativeBuildInputs = [ python3Packages.setuptools ];
+            checkInputs = tools python3Packages;
+          };
+        asyncdbview-pyextension = pyFinal: pyPrev: {
+          asyncdbview = pkgs.callPackage asyncdbview-package {
+            python3Packages = pyFinal;
+          };
+        };
+
+        overlay = final: prev: {
+          pythonPackagesExtensions =
+            prev.pythonPackagesExtensions ++ [ asyncdbview-pyextension ];
+        };
+        pkgs = import nixpkgs { inherit system; overlays = [ overlay ]; };
+
+        defaultPython3Packages = pkgs.python311Packages;  # 3.11+
+        asyncdbview = pkgs.callPackage asyncdbview-package {
+          python3Packages = defaultPython3Packages;
         };
       in
       {
         devShells.default = pkgs.mkShell {
-          buildInputs = [(python3Packages.python.withPackages deps)];
-          nativeBuildInputs = tools pkgs python3Packages;
+          buildInputs = [(defaultPython3Packages.python.withPackages deps)];
+          nativeBuildInputs = tools defaultPython3Packages;
           shellHook = ''
             export PYTHONASYNCIODEBUG=1 PYTHONWARNINGS=error
           '';
         };
         packages.asyncdbview = asyncdbview;
         packages.default = asyncdbview;
+        overlays.default = overlay;
       }
     );
 }