From 93525f783b1066d1239be953aafd67432da5bd25 Mon Sep 17 00:00:00 2001
From: Alan Zimmerman <alanzimm@meta.com>
Date: Thu, 22 Aug 2024 08:47:54 -0700
Subject: [PATCH] Add a comment for elp lint filtering

Summary: Add a clarification comment to elp lint about when exactly the enabled/disabled lints from config are used.

Reviewed By: robertoaloi

Differential Revision: D61649402

fbshipit-source-id: 1fae823a30605e9c301c34e6a7624021421aeaa9
---
 crates/elp/src/bin/lint_cli.rs | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/crates/elp/src/bin/lint_cli.rs b/crates/elp/src/bin/lint_cli.rs
index 75ec3fc42..13e46a181 100644
--- a/crates/elp/src/bin/lint_cli.rs
+++ b/crates/elp/src/bin/lint_cli.rs
@@ -362,6 +362,11 @@ fn filter_diagnostics<'a>(
     diags: &'a [(String, FileId, DiagnosticCollection)],
     changed_forms: &FxHashSet<InFile<FormIdx>>,
 ) -> Result<Vec<(String, FileId, Vec<diagnostics::Diagnostic>)>> {
+    // The initial set of diagnostics is filtered with a `Some` value
+    // for allowed_diagnostics. Thereafter, during the simplification
+    // stage, it is called with `None`.  This means
+    // `Category::SimplificationRule` is always enabled for that
+    // usage.
     Ok(diags
         .to_owned()
         .into_iter()