From 84a8b628b8a3b6aa8035c9f49b38392556aea32c Mon Sep 17 00:00:00 2001
From: Charlie Marsh <charlie.r.marsh@gmail.com>
Date: Tue, 31 Jan 2023 17:35:30 -0500
Subject: [PATCH] Avoid implicit-namespace-package checks for .pyi files
 (#2420)

---
 .../test_pass_pyi/example.pyi                 |  0
 src/rules/flake8_no_pep420/mod.rs             | 21 ++++++++++---------
 src/rules/flake8_no_pep420/rules.rs           |  2 +-
 ...lake8_no_pep420__tests__test_pass_pyi.snap |  6 ++++++
 4 files changed, 18 insertions(+), 11 deletions(-)
 create mode 100644 resources/test/fixtures/flake8_no_pep420/test_pass_pyi/example.pyi
 create mode 100644 src/rules/flake8_no_pep420/snapshots/ruff__rules__flake8_no_pep420__tests__test_pass_pyi.snap

diff --git a/resources/test/fixtures/flake8_no_pep420/test_pass_pyi/example.pyi b/resources/test/fixtures/flake8_no_pep420/test_pass_pyi/example.pyi
new file mode 100644
index 00000000000000..e69de29bb2d1d6
diff --git a/src/rules/flake8_no_pep420/mod.rs b/src/rules/flake8_no_pep420/mod.rs
index 04d38aeff3e5b2..e9505a660d107c 100644
--- a/src/rules/flake8_no_pep420/mod.rs
+++ b/src/rules/flake8_no_pep420/mod.rs
@@ -13,18 +13,19 @@ mod tests {
     use crate::registry::Rule;
     use crate::settings::Settings;
 
-    #[test_case(Path::new("test_pass_init"); "INP001_0")]
-    #[test_case(Path::new("test_fail_empty"); "INP001_1")]
-    #[test_case(Path::new("test_fail_nonempty"); "INP001_2")]
-    #[test_case(Path::new("test_fail_shebang"); "INP001_3")]
-    #[test_case(Path::new("test_ignored"); "INP001_4")]
-    #[test_case(Path::new("test_pass_namespace_package"); "INP001_5")]
-    fn test_flake8_no_pep420(path: &Path) -> Result<()> {
+    #[test_case(Path::new("test_pass_init"), Path::new("example.py"); "INP001_0")]
+    #[test_case(Path::new("test_fail_empty"), Path::new("example.py"); "INP001_1")]
+    #[test_case(Path::new("test_fail_nonempty"), Path::new("example.py"); "INP001_2")]
+    #[test_case(Path::new("test_fail_shebang"), Path::new("example.py"); "INP001_3")]
+    #[test_case(Path::new("test_ignored"), Path::new("example.py"); "INP001_4")]
+    #[test_case(Path::new("test_pass_namespace_package"), Path::new("example.py"); "INP001_5")]
+    #[test_case(Path::new("test_pass_pyi"), Path::new("example.pyi"); "INP001_6")]
+    fn test_flake8_no_pep420(path: &Path, filename: &Path) -> Result<()> {
         let snapshot = format!("{}", path.to_string_lossy());
-        // Platform-independent paths
         let p = PathBuf::from(format!(
-            "./resources/test/fixtures/flake8_no_pep420/{}/example.py",
-            path.display()
+            "./resources/test/fixtures/flake8_no_pep420/{}/{}",
+            path.display(),
+            filename.display()
         ));
         let diagnostics = test_path(
             p.as_path(),
diff --git a/src/rules/flake8_no_pep420/rules.rs b/src/rules/flake8_no_pep420/rules.rs
index 07d1fe9ba53f8d..7791e4a09d0ed0 100644
--- a/src/rules/flake8_no_pep420/rules.rs
+++ b/src/rules/flake8_no_pep420/rules.rs
@@ -20,7 +20,7 @@ impl Violation for ImplicitNamespacePackage {
 
 /// INP001
 pub fn implicit_namespace_package(path: &Path, package: Option<&Path>) -> Option<Diagnostic> {
-    if package.is_none() {
+    if package.is_none() && path.extension().map_or(true, |ext| ext != "pyi") {
         Some(Diagnostic::new(
             ImplicitNamespacePackage(fs::relativize_path(path)),
             Range::default(),
diff --git a/src/rules/flake8_no_pep420/snapshots/ruff__rules__flake8_no_pep420__tests__test_pass_pyi.snap b/src/rules/flake8_no_pep420/snapshots/ruff__rules__flake8_no_pep420__tests__test_pass_pyi.snap
new file mode 100644
index 00000000000000..622ebcff04079e
--- /dev/null
+++ b/src/rules/flake8_no_pep420/snapshots/ruff__rules__flake8_no_pep420__tests__test_pass_pyi.snap
@@ -0,0 +1,6 @@
+---
+source: src/rules/flake8_no_pep420/mod.rs
+expression: diagnostics
+---
+[]
+