add support for flakes

README.md

@@ -14,6 +14,7 @@ designed to work with nixpkgs but also other package sets.
 -   update buildRustPackage's cargoHash/cargoSha256 and cargoSetupHook's cargoDeps
 -   update buildGoModule's vendorHash/vendorSha256
 -   update buildNpmPackage's npmDepsHash and npmConfigHook's npmDeps
+-   update flake outputs (see `--flake`)
 -   build and run the resulting package (see `--build`,
     `--run` or `--shell`
 -   commit updated files (see `--commit` flag)

nix_update/__init__.py

@@ -20,6 +20,9 @@ def parse_args(args: list[str]) -> Options:
     parser = argparse.ArgumentParser()
     help = "File to import rather than default.nix. Examples, ./release.nix"
     parser.add_argument("-f", "--file", default="./.", help=help)
+    parser.add_argument(
+        "-F", "--flake", action="store_true", help="Update a flake attribute instead"
+    )
     parser.add_argument("--build", action="store_true", help="build the package")
     parser.add_argument(
         "--test", action="store_true", help="Run package's `passthru.tests`"
@@ -68,7 +71,8 @@ def parse_args(args: list[str]) -> Options:
     parser.add_argument("attribute", help="Attribute name within the file evaluated")
     a = parser.parse_args(args)
     return Options(
-        import_path=a.file,
+        import_path=os.path.realpath(a.file),
+        flake=a.flake,
         build=a.build,
         commit=a.commit,
         use_update_script=a.use_update_script,
@@ -87,13 +91,25 @@ def parse_args(args: list[str]) -> Options:
 
 
 def nix_shell(options: Options) -> None:
-    import_path = os.path.realpath(options.import_path)
-    expr = f"with import {import_path} {{}}; mkShell {{ buildInputs = [ {options.attribute} ]; }}"
-    with tempfile.TemporaryDirectory() as d:
-        path = os.path.join(d, "default.nix")
-        with open(path, "w") as f:
-            f.write(expr)
-        run(["nix-shell", path], stdout=None, check=False)
+    if options.flake:
+        run(
+            [
+                "nix",
+                "shell",
+                f"{options.import_path}#{options.attribute}",
+                "--extra-experimental-features",
+                "flakes nix-command",
+            ],
+            stdout=None,
+            check=False,
+        )
+    else:
+        expr = f"with import {options.import_path} {{}}; mkShell {{ buildInputs = [ {options.attribute} ]; }}"
+        with tempfile.TemporaryDirectory() as d:
+            path = os.path.join(d, "default.nix")
+            with open(path, "w") as f:
+                f.write(expr)
+            run(["nix-shell", path], stdout=None, check=False)
 
 
 def git_has_diff(git_dir: str, package: Package) -> bool:
@@ -172,37 +188,69 @@ def validate_git_dir(import_path: str) -> str:
 
 
 def nix_run(options: Options) -> None:
-    cmd = ["nix", "shell", "--extra-experimental-features", "nix-command"]
+    cmd = (
+        [
+            "nix",
+            "shell",
+            "--extra-experimental-features",
+            "flakes nix-command",
+            f"{options.import_path}#{options.attribute}",
+        ]
+        if options.flake
+        else [
+            "nix",
+            "shell",
+            "--extra-experimental-features",
+            "nix-command",
+            "-f",
+            options.import_path,
+            options.attribute,
+        ]
+    )
     run(
-        cmd + ["-f", options.import_path, options.attribute],
+        cmd,
         stdout=None,
         check=False,
     )
 
 
 def nix_build(options: Options) -> None:
-    cmd = [
-        "nix",
-        "build",
-        "--extra-experimental-features",
-        "nix-command",
-        "-L",
-        "-f",
-        options.import_path,
-        options.attribute,
-    ]
+    cmd = (
+        [
+            "nix",
+            "shell",
+            "--extra-experimental-features",
+            "flakes nix-command",
+            f"{options.import_path}#{options.attribute}",
+        ]
+        if options.flake
+        else [
+            "nix",
+            "build",
+            "--extra-experimental-features",
+            "nix-command",
+            "-L",
+            "-f",
+            options.import_path,
+            options.attribute,
+        ]
+    )
     run(cmd, stdout=None)
 
 
-def nix_test(package: Package) -> None:
+def nix_test(opts: Options, package: Package) -> None:
     if not package.tests:
         die(f"Package '{package.name}' does not define any tests")
 
-    tests = []
-    for t in package.tests:
-        tests.append("-A")
-        tests.append(f"{package.attribute}.tests.{t}")
-    cmd = ["nix-build"] + tests
+    if opts.flake:
+        cmd = ["nix", "build", "--experimental-features", "flakes nix-command"]
+        for t in package.tests:
+            cmd.append(f"{opts.import_path}#{package.attribute}.tests.{t}")
+    else:
+        cmd = ["nix-build"]
+        for t in package.tests:
+            cmd.append("-A")
+            cmd.append(f"{package.attribute}.tests.{t}")
     run(cmd, stdout=None)
 
 
@@ -251,10 +299,13 @@ def main(args: list[str] = sys.argv[1:]) -> None:
         return
 
     if options.test:
-        nix_test(package)
+        nix_test(options, package)
 
     if options.review:
-        nixpkgs_review()
+        if options.flake:
+            print("--review is unsupporetd with --flake")
+        else:
+            nixpkgs_review()
 
     if options.format:
         nixpkgs_fmt(package, git_dir)

nix_update/eval.py

@@ -53,43 +53,59 @@ class Package:
             self.version_position = Position(**raw_version_position)
 
 
-def eval_expression(import_path: str, attr: str) -> str:
-    return f"""(
-    let
-      inputs = (if (builtins.hasAttr "overlays" (builtins.functionArgs (import {import_path}))) then {{ overlays = []; }} else {{ }});
-    in
-    with import {import_path} inputs;
-    let
-      pkg = {attr};
-      raw_version_position = builtins.unsafeGetAttrPos "version" pkg;
+def eval_expression(import_path: str, attr: str, flake: bool) -> str:
+    let_bindings = (
+        f"""inherit (builtins) currentSystem getFlake stringLength substring;
+  flake = getFlake "{import_path}";
+  pkg = flake.packages.${{currentSystem}}.{attr} or flake.{attr};
+  inherit (flake) outPath;
+  outPathLen = stringLength outPath;
+  sanitizePosition = {{ file, ... }}@pos:
+    assert substring 0 outPathLen file == outPath;
+    pos // {{ file = "{import_path}" + substring outPathLen (stringLength file - outPathLen) file; }};"""
+        if flake
+        else f"""
+  inputs = if (builtins.functionArgs (import {import_path})) ? overlays then {{ overlays = [ ]; }} else {{ }};
+  pkg = (import {import_path} inputs).{attr};
+  sanitizePosition = x: x;"""
+    )
 
-      position = if pkg ? isRubyGem then
-        raw_version_position
-      else
-        builtins.unsafeGetAttrPos "src" pkg;
-    in {{
-      name = pkg.name;
-      old_version = pkg.version or (builtins.parseDrvName pkg.name).version;
-      inherit raw_version_position;
-      filename = position.file;
-      line = position.line;
-      urls = pkg.src.urls or null;
-      url = pkg.src.url or null;
-      rev = pkg.src.rev or null;
-      hash = pkg.src.outputHash or null;
-      vendor_hash = pkg.vendorHash or null;
-      vendor_sha256 = pkg.vendorSha256 or null;
-      cargo_deps = (pkg.cargoDeps or null).outputHash or null;
-      npm_deps = (pkg.npmDeps or null).outputHash or null;
-      tests = builtins.attrNames (pkg.passthru.tests or {{}});
-      has_update_script = pkg.passthru.updateScript or null != null;
-      src_homepage = pkg.src.meta.homepage or null;
-      changelog = pkg.meta.changelog or null;
-    }})"""
+    has_update_script = (
+        "false" if flake else "pkg.passthru.updateScript or null != null"
+    )
+
+    return f"""
+let
+  {let_bindings}
+  raw_version_position = sanitizePosition (builtins.unsafeGetAttrPos "version" pkg);
+
+  position = if pkg ? isRubyGem then
+    raw_version_position
+  else
+    sanitizePosition (builtins.unsafeGetAttrPos "src" pkg);
+in {{
+  name = pkg.name;
+  old_version = pkg.version or (builtins.parseDrvName pkg.name).version;
+  inherit raw_version_position;
+  filename = position.file;
+  line = position.line;
+  urls = pkg.src.urls or null;
+  url = pkg.src.url or null;
+  rev = pkg.src.rev or null;
+  hash = pkg.src.outputHash or null;
+  vendor_hash = pkg.vendorHash or null;
+  vendor_sha256 = pkg.vendorSha256 or null;
+  cargo_deps = pkg.cargoDeps.outputHash or null;
+  npm_deps = pkg.npmDeps.outputHash or null;
+  tests = builtins.attrNames (pkg.passthru.tests or {{}});
+  has_update_script = {has_update_script};
+  src_homepage = pkg.src.meta.homepage or null;
+  changelog = pkg.meta.changelog or null;
+}}"""
 
 
 def eval_attr(opts: Options) -> Package:
-    expr = eval_expression(opts.import_path, opts.attribute)
+    expr = eval_expression(opts.import_path, opts.attribute, opts.flake)
     cmd = [
         "nix",
         "eval",

nix_update/options.py

@@ -1,3 +1,4 @@
+import os
 from dataclasses import dataclass
 from typing import Optional
 
@@ -7,10 +8,11 @@ from .version.version import VersionPreference
 @dataclass
 class Options:
     attribute: str
+    flake: bool = False
     version: str = "stable"
     version_preference: VersionPreference = VersionPreference.STABLE
     version_regex: str = "(.*)"
-    import_path: str = "./."
+    import_path: str = os.getcwd()
     override_filename: Optional[str] = None
     commit: bool = False
     use_update_script: bool = False

nix_update/update.py

@@ -105,29 +105,31 @@ def disable_check_meta(opts: Options) -> str:
     return f'(if (builtins.hasAttr "config" (builtins.functionArgs (import {opts.import_path}))) then {{ config.checkMeta = false; overlays = []; }} else {{ }})'
 
 
-def update_src_hash(opts: Options, filename: str, current_hash: str) -> None:
-    expr = (
-        f"(import {opts.import_path} {disable_check_meta(opts)}).{opts.attribute}.src"
+def get_attr(opts: Options, attr: str) -> str:
+    return (
+        f'let flake = builtins.getFlake "{opts.import_path}"; in (flake.packages.${{builtins.currentSystem}}.{opts.attribute} or flake.{opts.attribute}).{attr}'
+        if opts.flake
+        else f"(import {opts.import_path} {disable_check_meta(opts)}).{opts.attribute}.{attr}"
     )
-    target_hash = nix_prefetch(expr)
+
+
+def update_src_hash(opts: Options, filename: str, current_hash: str) -> None:
+    target_hash = nix_prefetch(get_attr(opts, "src"))
     replace_hash(filename, current_hash, target_hash)
 
 
 def update_go_modules_hash(opts: Options, filename: str, current_hash: str) -> None:
-    expr = f"(import {opts.import_path} {disable_check_meta(opts)}).{opts.attribute}.go-modules"
-    target_hash = nix_prefetch(expr)
+    target_hash = nix_prefetch(get_attr(opts, "go-modules"))
     replace_hash(filename, current_hash, target_hash)
 
 
 def update_cargo_deps_hash(opts: Options, filename: str, current_hash: str) -> None:
-    expr = f"(import {opts.import_path} {disable_check_meta(opts)}).{opts.attribute}.cargoDeps"
-    target_hash = nix_prefetch(expr)
+    target_hash = nix_prefetch(get_attr(opts, "cargoDeps"))
     replace_hash(filename, current_hash, target_hash)
 
 
 def update_npm_deps_hash(opts: Options, filename: str, current_hash: str) -> None:
-    expr = f"(import {opts.import_path} {disable_check_meta(opts)}).{opts.attribute}.npmDeps"
-    target_hash = nix_prefetch(expr)
+    target_hash = nix_prefetch(get_attr(opts, "npmDeps"))
     replace_hash(filename, current_hash, target_hash)