Read Cargo lints from declared manifests

cargo/private/cargo_toml_info/BUILD.bazel

@@ -1,5 +1,6 @@
 """BUILD file for cargo info helper binary."""
 
+load("@rules_python//python:defs.bzl", "py_test")
 load("//rust:defs.bzl", "rust_binary", "rust_test")
 
 rust_binary(
@@ -14,3 +15,11 @@ rust_test(
     name = "unit_test",
     crate = ":cargo_toml_info",
 )
+
+py_test(
+    name = "declared_manifests_test",
+    srcs = ["declared_manifests_test.py"],
+    args = ["$(rlocationpath :cargo_toml_info)"],
+    data = [":cargo_toml_info"],
+    deps = ["@rules_python//python/runfiles"],
+)

cargo/private/cargo_toml_info/declared_manifests_test.py

@@ -0,0 +1,89 @@
+"""Lint extraction uses only the declared package and workspace manifests."""
+
+import os
+import subprocess
+import sys
+import tempfile
+import unittest
+from pathlib import Path
+
+from python.runfiles import runfiles
+
+WORKSPACE = """\
+[workspace]
+members = ["missing-member"]
+
+[workspace.package]
+version = "0.1.0"
+readme = "missing-readme.md"
+
+[workspace.lints.rust]
+unused = { level = "deny", priority = -1 }
+unsafe_code = "forbid"
+
+[workspace.lints.clippy]
+all = "warn"
+"""
+
+PACKAGE = """\
+[package]
+name = "example"
+version.workspace = true
+readme.workspace = true
+edition = "2021"
+
+[lints]
+workspace = true
+"""
+
+
+class DeclaredManifestsTest(unittest.TestCase):
+    def test_root_and_member_inherit_lints_without_workspace_sources(self):
+        lookup = runfiles.Create()
+        self.assertIsNotNone(lookup)
+        executable = lookup.Rlocation(EXTRACTOR)
+        self.assertIsNotNone(executable)
+
+        with tempfile.TemporaryDirectory(
+            dir=os.environ.get("TEST_TMPDIR")
+        ) as directory:
+            root = Path(directory)
+            workspace = root / "Cargo.toml"
+            workspace.write_text(WORKSPACE + "\n" + PACKAGE)
+            member = root / "member" / "Cargo.toml"
+            member.parent.mkdir()
+            member.write_text(PACKAGE)
+
+            for package in (workspace, member):
+                with self.subTest(package=package):
+                    outputs = [
+                        root / f"{package.parent.name}.{group}.lints"
+                        for group in ("rustc", "clippy", "rustdoc")
+                    ]
+                    result = subprocess.run(
+                        [
+                            executable,
+                            f"--manifest_toml={package.relative_to(root)}",
+                            f"--workspace_toml={workspace.relative_to(root)}",
+                            "lints",
+                            *(str(path) for path in outputs),
+                        ],
+                        cwd=root,
+                        capture_output=True,
+                        text=True,
+                        check=False,
+                    )
+                    self.assertEqual(0, result.returncode, result.stderr)
+                    self.assertEqual(
+                        ["--deny=unused", "--forbid=unsafe_code"],
+                        outputs[0].read_text().splitlines(),
+                    )
+                    self.assertEqual(
+                        ["--warn=clippy::all"], outputs[1].read_text().splitlines()
+                    )
+                    self.assertEqual("", outputs[2].read_text())
+
+
+if __name__ == "__main__":
+    EXTRACTOR = sys.argv.pop(1)
+    unittest.main()

cargo/private/cargo_toml_info/main.rs

@@ -21,18 +21,13 @@ pub fn main() -> Result<(), Box<dyn Error>> {
     } = Args::try_from(std::env::args())?;
 
     let manifest_contents = std::fs::read_to_string(&manifest_toml)?;
-    let mut crate_manifest = Manifest::from_str(&manifest_contents)?;
+    let crate_manifest = Manifest::from_str(&manifest_contents)?;
     let mut workspace_manifest = None;
 
-    // Optionally populate the manifest with info from the parent workspace, if one is provided.
+    // Lint extraction only needs the declared manifests. Completing the package
+    // from disk would require undeclared sources and workspace members.
     if let Some(workspace_path) = workspace_toml {
-        let manifest = Manifest::from_path(&workspace_path)?;
-        let workspace_details = Some((&manifest, workspace_path.as_path()));
-
-        // TODO(parkmycar): Fix cargo_toml so we inherit lints from our workspace.
-        //
-        // See: <https://gitlab.com/lib.rs/cargo_toml/-/issues/35>
-        crate_manifest.complete_from_path_and_workspace(&manifest_toml, workspace_details)?;
+        let manifest = Manifest::from_str(&std::fs::read_to_string(workspace_path)?)?;
         workspace_manifest = Some(manifest);
     }