fix(es/minifier): Don't convert a signed integer literal key to a numeric literal (#6529)

**Related issue:**

 - Closes #6528.

Author: hyp3rflow

crates/swc_ecma_minifier/src/compress/pure/properties.rs

@@ -95,7 +95,7 @@ impl Pure<'_> {
                 return;
             }
 
-            if !s.value.starts_with('0') || s.value.len() <= 1 {
+            if (!s.value.starts_with('0') && !s.value.starts_with('+')) || s.value.len() <= 1 {
                 if let Ok(v) = s.value.parse::<u32>() {
                     self.changed = true;
                     report_change!("misc: Optimizing numeric property name");

crates/swc_ecma_minifier/tests/exec.rs

@@ -10374,3 +10374,23 @@ fn issue_6463_1() {
         "###,
     );
 }
+
+#[test]
+fn issue_6528() {
+    run_default_exec_test(
+        r###"
+        const foo = {
+            "+1": 1,
+            "2": 2,
+            "-3": 3,
+        }
+
+        console.log(foo[1]);
+        console.log(foo["+1"]);
+        console.log(foo["2"]);
+        console.log(foo[2]);
+        console.log(foo[-3]);
+        console.log(foo["-3"]);
+        "###,
+    )
+}