fix(go) highlight the name of a method with a receiver

CHANGES.md

@@ -14,6 +14,7 @@ Core Grammars:
 - fix(c, cpp) stop a raw string's closing delimiter from swallowing quotes, which broke highlighting of everything after the literal, issue #3585 [David Pavlovschii][]
 - enh(python) add missing builtins: `aiter` and `anext` (Python 3.10), `frozendict` and `sentinel` (Python 3.15) [Hugo van Kemenade][]
 - enh(python) Support t-strings [Nicolas Le Cam][]
+- fix(go) highlight the name of a method with a receiver, e.g. `func (c *exec.Cmd) Run()`, issue #4196 [Ali Asgher][]
 
 Documentation:
 
@@ -33,6 +34,7 @@ CONTRIBUTORS
 [Nicolas Le Cam]: https://github.com/KuSh
 [Konstantin Baltsat]: https://github.com/Baltsat
 [David Pavlovschii]: https://github.com/davidpavlovschi
+[Ali Asgher]: https://github.com/alliasgher
 
 
 ## Version 11.11.3

src/languages/go.js

@@ -8,6 +8,7 @@ Category: common, system
 */
 
 export default function(hljs) {
+  const regex = hljs.regex;
   const LITERALS = [
     "true",
     "false",
@@ -86,6 +87,22 @@ export default function(hljs) {
     literal: LITERALS,
     built_in: BUILT_INS
   };
+  const PARAMS = {
+    className: 'params',
+    begin: /\(/,
+    end: /\)/,
+    endsParent: true,
+    keywords: KEYWORDS,
+    illegal: /["']/
+  };
+  // a method's receiver, ie the `(c *exec.Cmd)` of `func (c *exec.Cmd) Run()` -
+  // it must not end the function mode, otherwise the method name that follows
+  // it is never seen; only a parenthesized group directly followed by
+  // `name(` qualifies, so a plain function's argument list is unaffected
+  const RECEIVER = hljs.inherit(PARAMS, {
+    begin: regex.concat(/\(/, regex.lookahead(/[^)]+\)\s*(?!func\b)[a-zA-Z_]\w*\s*\(/)),
+    endsParent: false
+  });
   return {
     name: 'Go',
     aliases: [ 'golang' ],
@@ -142,15 +159,9 @@ export default function(hljs) {
         end: '\\s*(\\{|$)',
         excludeEnd: true,
         contains: [
+          RECEIVER,
           hljs.TITLE_MODE,
-          {
-            className: 'params',
-            begin: /\(/,
-            end: /\)/,
-            endsParent: true,
-            keywords: KEYWORDS,
-            illegal: /["']/
-          }
+          PARAMS
         ]
       }
     ]

test/markup/go/methods.expect.txt

@@ -0,0 +1,15 @@
+<span class="hljs-function"><span class="hljs-keyword">func</span> <span class="hljs-params">(c *exec.Cmd)</span> <span class="hljs-title">Run</span><span class="hljs-params">()</span></span> <span class="hljs-type">error</span>
+
+<span class="hljs-function"><span class="hljs-keyword">func</span> <span class="hljs-params">(m sync.Mutex)</span> <span class="hljs-title">Lock</span><span class="hljs-params">()</span></span>
+
+<span class="hljs-function"><span class="hljs-keyword">func</span> <span class="hljs-params">(*sync.Mutex)</span> <span class="hljs-title">Unlock</span><span class="hljs-params">()</span></span>
+
+<span class="hljs-function"><span class="hljs-keyword">func</span> <span class="hljs-params">(s *Stack[T])</span> <span class="hljs-title">Push</span><span class="hljs-params">(v T)</span></span> {
+  s.items = <span class="hljs-built_in">append</span>(s.items, v)
+}
+
+<span class="hljs-function"><span class="hljs-keyword">func</span> <span class="hljs-params">(mt MyType)</span> <span class="hljs-title">MyFunc</span><span class="hljs-params">(<span class="hljs-type">int</span>, <span class="hljs-type">float32</span>)</span></span> (<span class="hljs-type">int</span>, io.Reader, <span class="hljs-type">error</span>) {
+  <span class="hljs-keyword">return</span> <span class="hljs-number">0</span>, <span class="hljs-literal">nil</span>, <span class="hljs-literal">nil</span>
+}
+
+<span class="hljs-function"><span class="hljs-keyword">func</span> <span class="hljs-title">middleware</span><span class="hljs-params">(h Handler)</span></span> <span class="hljs-function"><span class="hljs-keyword">func</span><span class="hljs-params">(<span class="hljs-type">int32</span>)</span></span> <span class="hljs-type">int32</span>

test/markup/go/methods.txt

@@ -0,0 +1,15 @@
+func (c *exec.Cmd) Run() error
+
+func (m sync.Mutex) Lock()
+
+func (*sync.Mutex) Unlock()
+
+func (s *Stack[T]) Push(v T) {
+  s.items = append(s.items, v)
+}
+
+func (mt MyType) MyFunc(int, float32) (int, io.Reader, error) {
+  return 0, nil, nil
+}
+
+func middleware(h Handler) func(int32) int32