fix(eslint-plugin): [unified-signatures] fix false positives for ignoreOverloadsWithDifferentJSDoc option (#11381)

* fix: improve comment comparison logic for overload unification

* test: add cases for overloads with different comments and class methods

Author: y-hsgw

packages/eslint-plugin/src/rules/unified-signatures.ts

@@ -241,9 +241,8 @@ export default createRule<Options, MessageIds>({
       }
 
       if (ignoreOverloadsWithDifferentJSDoc) {
-        const aComment = getBlockCommentForNode(getExportingNode(a) ?? a);
-        const bComment = getBlockCommentForNode(getExportingNode(b) ?? b);
-
+        const aComment = getBlockCommentForNode(getCommentTargetNode(a));
+        const bComment = getBlockCommentForNode(getCommentTargetNode(b));
         if (aComment?.value !== bComment?.value) {
           return false;
         }
@@ -657,6 +656,14 @@ export default createRule<Options, MessageIds>({
   },
 });
 
+function getCommentTargetNode(node: SignatureDefinition) {
+  if (node.type === AST_NODE_TYPES.TSEmptyBodyFunctionExpression) {
+    return node.parent;
+  }
+
+  return getExportingNode(node) ?? node;
+}
+
 function getExportingNode(
   node: SignatureDefinition,
 ):

packages/eslint-plugin/tests/rules/unified-signatures.test.ts

@@ -378,6 +378,19 @@ declare function f(x: boolean): unknown;
 declare function f(x: number): unknown;
 declare function f(x: boolean): unknown;
       `,
+
+      options: [{ ignoreOverloadsWithDifferentJSDoc: true }],
+    },
+    {
+      code: `
+class C {
+  a(b: string): void;
+  /**
+   * @deprecate
+   */
+  a(b: number): void;
+}
+      `,
       options: [{ ignoreOverloadsWithDifferentJSDoc: true }],
     },
     `
@@ -833,6 +846,30 @@ abstract class Foo {
         },
       ],
     },
+    {
+      code: `
+abstract class C {
+  a(b: string): void;
+  /**
+   * @deprecate
+   */
+  a(b: number): void;
+}
+      `,
+      errors: [
+        {
+          column: 5,
+          data: {
+            failureStringStart:
+              'These overloads can be combined into one signature',
+            type1: 'string',
+            type2: 'number',
+          },
+          line: 7,
+          messageId: 'singleParameterDifference',
+        },
+      ],
+    },
     {
       // Works with literals
       code: `