From 05636b772583758071c0d378f5236a609a8b7f09 Mon Sep 17 00:00:00 2001
From: overlookmotel <557937+overlookmotel@users.noreply.github.com>
Date: Fri, 30 Aug 2024 12:52:39 +0000
Subject: [PATCH] perf(linter): avoid unnecessary work in
 `jsx_a11y/anchor_is_valid` rule (#5341)

Follow-on after #5223.

#5223 introduced the line `let span = jsx_el.opening_element.name.span();`. But the span is only needed when creating a diagnostic when the rule fails (cold path). Avoid the work of getting the span for the common case where the rule passes.
---
 .../oxc_linter/src/rules/jsx_a11y/anchor_is_valid.rs  | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/crates/oxc_linter/src/rules/jsx_a11y/anchor_is_valid.rs b/crates/oxc_linter/src/rules/jsx_a11y/anchor_is_valid.rs
index eb6936507db3e..1a0a68f5cf1c6 100644
--- a/crates/oxc_linter/src/rules/jsx_a11y/anchor_is_valid.rs
+++ b/crates/oxc_linter/src/rules/jsx_a11y/anchor_is_valid.rs
@@ -135,7 +135,8 @@ impl Rule for AnchorIsValid {
             if name != "a" {
                 return;
             };
-            let span = jsx_el.opening_element.name.span();
+            // Don't eagerly get `span` here, to avoid that work unless rule fails
+            let get_span = || jsx_el.opening_element.name.span();
             if let Option::Some(href_attr) =
                 has_jsx_prop_ignore_case(&jsx_el.opening_element, "href")
             {
@@ -145,17 +146,17 @@ impl Rule for AnchorIsValid {
 
                 // Check if the 'a' element has a correct href attribute
                 let Some(value) = attr.value.as_ref() else {
-                    ctx.diagnostic(incorrect_href(span));
+                    ctx.diagnostic(incorrect_href(get_span()));
                     return;
                 };
 
                 let is_empty = self.check_value_is_empty(value);
                 if is_empty {
                     if has_jsx_prop_ignore_case(&jsx_el.opening_element, "onclick").is_some() {
-                        ctx.diagnostic(cant_be_anchor(span));
+                        ctx.diagnostic(cant_be_anchor(get_span()));
                         return;
                     }
-                    ctx.diagnostic(incorrect_href(span));
+                    ctx.diagnostic(incorrect_href(get_span()));
                     return;
                 }
                 return;
@@ -168,7 +169,7 @@ impl Rule for AnchorIsValid {
             if has_spread_attr {
                 return;
             }
-            ctx.diagnostic(missing_href_attribute(span));
+            ctx.diagnostic(missing_href_attribute(get_span()));
         }
     }
 }