[red-knot] Add more tests asserting that the VendoredFileSystem and t…

…he `VERSIONS` parser work with the vendored typeshed stubs (#11970)

crates/red_knot_module_resolver/Cargo.toml

@@ -27,7 +27,9 @@ zip = { workspace = true }
 [dev-dependencies]
 anyhow = { workspace = true }
 insta = { workspace = true }
+path-slash = { workspace = true }
 tempfile = { workspace = true }
+walkdir = { workspace = true }
 
 [lints]
 workspace = true

crates/red_knot_module_resolver/src/typeshed.rs

@@ -5,14 +5,20 @@ mod tests {
     use std::io::{self, Read};
     use std::path::Path;
 
-    #[test]
-    fn typeshed_zip_created_at_build_time() -> anyhow::Result<()> {
-        // The file path here is hardcoded in this crate's `build.rs` script.
-        // Luckily this crate will fail to build if this file isn't available at build time.
-        const TYPESHED_ZIP_BYTES: &[u8] =
-            include_bytes!(concat!(env!("OUT_DIR"), "/zipped_typeshed.zip"));
+    use path_slash::PathExt;
+
+    use ruff_db::vendored::VendoredFileSystem;
+    use ruff_db::vfs::VendoredPath;
 
-        let mut typeshed_zip_archive = zip::ZipArchive::new(io::Cursor::new(TYPESHED_ZIP_BYTES))?;
+    // The file path here is hardcoded in this crate's `build.rs` script.
+    // Luckily this crate will fail to build if this file isn't available at build time.
+    const TYPESHED_ZIP_BYTES: &[u8] =
+        include_bytes!(concat!(env!("OUT_DIR"), "/zipped_typeshed.zip"));
+
+    #[test]
+    fn typeshed_zip_created_at_build_time() {
+        let mut typeshed_zip_archive =
+            zip::ZipArchive::new(io::Cursor::new(TYPESHED_ZIP_BYTES)).unwrap();
 
         let path_to_functools = Path::new("stdlib").join("functools.pyi");
         let mut functools_module_stub = typeshed_zip_archive
@@ -21,9 +27,59 @@ mod tests {
         assert!(functools_module_stub.is_file());
 
         let mut functools_module_stub_source = String::new();
-        functools_module_stub.read_to_string(&mut functools_module_stub_source)?;
+        functools_module_stub
+            .read_to_string(&mut functools_module_stub_source)
+            .unwrap();
 
         assert!(functools_module_stub_source.contains("def update_wrapper("));
-        Ok(())
+    }
+
+    #[test]
+    fn typeshed_vfs_consistent_with_vendored_stubs() {
+        let vendored_typeshed_dir = Path::new("vendor/typeshed").canonicalize().unwrap();
+        let vendored_typeshed_stubs = VendoredFileSystem::new(TYPESHED_ZIP_BYTES).unwrap();
+
+        let mut empty_iterator = true;
+        for entry in walkdir::WalkDir::new(&vendored_typeshed_dir).min_depth(1) {
+            empty_iterator = false;
+            let entry = entry.unwrap();
+            let absolute_path = entry.path();
+            let file_type = entry.file_type();
+
+            let relative_path = absolute_path
+                .strip_prefix(&vendored_typeshed_dir)
+                .unwrap_or_else(|_| {
+                    panic!("Expected {absolute_path:?} to be a child of {vendored_typeshed_dir:?}")
+                });
+
+            let posix_style_path = relative_path
+                .to_slash()
+                .unwrap_or_else(|| panic!("Expected {relative_path:?} to be a valid UTF-8 path"));
+
+            let vendored_path = VendoredPath::new(&*posix_style_path);
+
+            assert!(
+                vendored_typeshed_stubs.exists(vendored_path),
+                "Expected {vendored_path:?} to exist in the `VendoredFileSystem`!"
+            );
+
+            let vendored_path_kind = vendored_typeshed_stubs
+                .metadata(vendored_path)
+                .unwrap_or_else(|| {
+                    panic!("Expected metadata for {vendored_path:?} to be retrievable from the `VendoredFileSystem!")
+                })
+                .kind();
+
+            assert_eq!(
+                vendored_path_kind.is_directory(),
+                file_type.is_dir(),
+                "{vendored_path:?} had type {vendored_path_kind:?}, inconsistent with fs path {relative_path:?}: {file_type:?}"
+            );
+        }
+
+        assert!(
+            !empty_iterator,
+            "Expected there to be at least one file or directory in the vendored typeshed stubs!"
+        );
     }
 }

crates/red_knot_module_resolver/src/typeshed/versions.rs

@@ -308,11 +308,14 @@ impl From<SupportedPyVersion> for PyVersion {
 #[cfg(test)]
 mod tests {
     use std::num::{IntErrorKind, NonZeroU16};
+    use std::path::Path;
 
     use super::*;
 
     use insta::assert_snapshot;
 
+    const TYPESHED_STDLIB_DIR: &str = "stdlib";
+
     #[allow(unsafe_code)]
     const ONE: NonZeroU16 = unsafe { NonZeroU16::new_unchecked(1) };
 
@@ -345,6 +348,60 @@ mod tests {
         assert!(!versions.module_exists_on_version(audioop, SupportedPyVersion::Py313));
     }
 
+    #[test]
+    fn typeshed_versions_consistent_with_vendored_stubs() {
+        const VERSIONS_DATA: &str = include_str!("../../vendor/typeshed/stdlib/VERSIONS");
+        let vendored_typeshed_dir = Path::new("vendor/typeshed").canonicalize().unwrap();
+        let vendored_typeshed_versions = TypeshedVersions::from_str(VERSIONS_DATA).unwrap();
+
+        let mut empty_iterator = true;
+
+        let stdlib_stubs_path = vendored_typeshed_dir.join(TYPESHED_STDLIB_DIR);
+
+        for entry in std::fs::read_dir(&stdlib_stubs_path).unwrap() {
+            empty_iterator = false;
+            let entry = entry.unwrap();
+            let absolute_path = entry.path();
+
+            let relative_path = absolute_path
+                .strip_prefix(&stdlib_stubs_path)
+                .unwrap_or_else(|_| panic!("Expected path to be a child of {stdlib_stubs_path:?} but found {absolute_path:?}"));
+
+            let relative_path_str = relative_path.as_os_str().to_str().unwrap_or_else(|| {
+                panic!("Expected all typeshed paths to be valid UTF-8; got {relative_path:?}")
+            });
+            if relative_path_str == "VERSIONS" {
+                continue;
+            }
+
+            let top_level_module = if let Some(extension) = relative_path.extension() {
+                // It was a file; strip off the file extension to get the module name:
+                let extension = extension
+                    .to_str()
+                    .unwrap_or_else(||panic!("Expected all file extensions to be UTF-8; was not true for {relative_path:?}"));
+
+                relative_path_str
+                    .strip_suffix(extension)
+                    .and_then(|string| string.strip_suffix('.')).unwrap_or_else(|| {
+                        panic!("Expected path {relative_path_str:?} to end with computed extension {extension:?}")
+                })
+            } else {
+                // It was a directory; no need to do anything to get the module name
+                relative_path_str
+            };
+
+            let top_level_module = ModuleName::new(top_level_module)
+                .unwrap_or_else(|| panic!("{top_level_module:?} was not a valid module name!"));
+
+            assert!(vendored_typeshed_versions.contains_module(&top_level_module));
+        }
+
+        assert!(
+            !empty_iterator,
+            "Expected there to be at least one file or directory in the vendored typeshed stubs"
+        );
+    }
+
     #[test]
     fn can_parse_mock_versions_file() {
         const VERSIONS: &str = "\