add fetchCrate support

README.md

@@ -6,6 +6,7 @@ designed to work with nixpkgs but also other package sets.
 ## Features
 
 -   automatically figure out the latest version of packages from:
+    -   crates.io
     -   github.com
     -   gitlab.com or other instances that uses fetchFromGitLab
     -   pypi

nix_update/version/__init__.py

@@ -3,6 +3,7 @@ from typing import List, Callable, Optional
 import re
 
 from ..errors import VersionError
+from .crate import fetch_crate_versions
 from .github import fetch_github_versions
 from .gitlab import fetch_gitlab_versions
 from .pypi import fetch_pypi_versions
@@ -21,6 +22,7 @@ from .version import VersionPreference, Version
 #    return None
 
 fetchers: List[Callable[[ParseResult], List[Version]]] = [
+    fetch_crate_versions,
     fetch_pypi_versions,
     fetch_github_versions,
     fetch_gitlab_versions,

nix_update/version/crate.py

@@ -0,0 +1,19 @@
+import json
+import urllib.request
+from typing import List
+from urllib.parse import ParseResult
+
+from ..utils import info
+from .version import Version
+
+
+def fetch_crate_versions(url: ParseResult) -> List[Version]:
+    if url.netloc != "crates.io":
+        return []
+    parts = url.path.split("/")
+    package = parts[4]
+    crate_url = f"https://crates.io/api/v1/crates/{package}/versions"
+    info(f"fetch {crate_url}")
+    resp = urllib.request.urlopen(crate_url)
+    data = json.loads(resp.read())
+    return [Version(version["num"]) for version in data["versions"]]

tests/test_crate.py

@@ -0,0 +1,27 @@
+#!/usr/bin/env python3
+
+from nix_update.options import Options
+from nix_update.update import update
+import subprocess
+import conftest
+
+
+def test_update(helpers: conftest.Helpers) -> None:
+    with helpers.testpkgs() as path:
+        opts = Options(attribute="crate", import_path=str(path))
+        update(opts)
+        version = subprocess.run(
+            [
+                "nix",
+                "eval",
+                "--raw",
+                "--extra-experimental-features",
+                "nix-command",
+                "-f",
+                path,
+                "crate.version",
+            ],
+            text=True,
+            stdout=subprocess.PIPE,
+        )
+        assert version.stdout.strip() >= "8.5.2"

tests/testpkgs/crate.nix

@@ -0,0 +1,13 @@
+{ rustPlatform, fetchCrate }:
+
+rustPlatform.buildRustPackage rec {
+  pname = "fd-find";
+  version = "8.0.0";
+
+  src = fetchCrate {
+    inherit pname version;
+    sha256 = "";
+  };
+
+  cargoSha256 = "";
+}

tests/testpkgs/default.nix

@@ -1,5 +1,6 @@
 { pkgs ? import <nixpkgs> {} }:
 {
+  crate = pkgs.callPackage ./crate.nix {};
   pypi = pkgs.python3.pkgs.callPackage ./pypi.nix {};
   sourcehut = pkgs.python3.pkgs.callPackage ./sourcehut.nix {};
   savanna = pkgs.python3.pkgs.callPackage ./savanna.nix {};