Properly highlight function name in letfn form

Author: rrudakov

CHANGELOG.md

@@ -3,19 +3,20 @@
 ## main (unreleased)
 
 - [#62](https://github.com/clojure-emacs/clojure-ts-mode/issues/62): Define `list` "thing" to improve navigation in Emacs 31.
-- [#64]: Add defcustom `clojure-ts-auto-remap` to control remapping of `clojure-mode` buffers.
-- Improve syntax highlighting:
+- [#64](https://github.com/clojure-emacs/clojure-ts-mode/pull/64): Add defcustom `clojure-ts-auto-remap` to control remapping of `clojure-mode` buffers.
+- [#66](https://github.com/clojure-emacs/clojure-ts-mode/pull/66): Improve syntax highlighting:
   - Highlight metadata with single keyword with `clojure-ts-keyword-face`.
   - Only highlight built-ins from `clojure.core` namespace.
   - Highlight named lambda functions properly.
   - Fix syntax highlighting for functions and vars with metadata on the previous
     line.
-- Improve semantic indentation rules to be more consistent with cljfmt.
-- Introduce `clojure-ts-semantic-indent-rules` customization option.
+- [#67](https://github.com/clojure-emacs/clojure-ts-mode/pull/67): Improve semantic indentation rules to be more consistent with cljfmt.
+- [#67](https://github.com/clojure-emacs/clojure-ts-mode/pull/67): Introduce `clojure-ts-semantic-indent-rules` customization option.
 - [#61](https://github.com/clojure-emacs/clojure-ts-mode/issues/61): Fix issue with indentation of collection items with metadata.
-- Proper syntax highlighting for expressions with metadata.
-- Add basic support for dynamic indentation via `clojure-ts-get-indent-function`.
-- Add support for nested indentation rules.
+- [#68](https://github.com/clojure-emacs/clojure-ts-mode/pull/68): Proper syntax highlighting for expressions with metadata.
+- [#69](https://github.com/clojure-emacs/clojure-ts-mode/pull/69): Add basic support for dynamic indentation via `clojure-ts-get-indent-function`.
+- [#70](https://github.com/clojure-emacs/clojure-ts-mode/pull/70): Add support for nested indentation rules.
+- [#71](https://github.com/clojure-emacs/clojure-ts-mode/pull/71): Properly highlight function name in `letfn` form.
 
 ## 0.2.3 (2025-03-04)
 

clojure-ts-mode.el

@@ -473,7 +473,14 @@ with the markdown_inline grammar."
         ((sym_lit name: (sym_name) @def)
          ((:equal "reify" @def)))
         (list_lit
-         (sym_lit name: (sym_name) @font-lock-function-name-face)))))
+         (sym_lit name: (sym_name) @font-lock-function-name-face))))
+      ;; letfn
+      ((list_lit
+        ((sym_lit name: (sym_name) @symbol)
+         ((:equal "letfn" @symbol)))
+        (vec_lit
+         (list_lit
+          (sym_lit name: (sym_name) @font-lock-function-name-face))))))
 
     :feature 'variable ;; def, defonce
     :language 'clojure

test/clojure-ts-mode-font-lock-test.el

@@ -167,4 +167,56 @@ DESCRIPTION is the description of the spec."
   (when-fontifying-it "special-forms-with-metadata"
     ("^long (if true 1 2)"
      (2 5 font-lock-type-face)
-     (8 9 font-lock-keyword-face))))
+     (8 9 font-lock-keyword-face)))
+
+  (when-fontifying-it "should highlight function name in all known forms"
+    ("(letfn [(add [x y]
+          (+ x y))
+        (hello [user]
+          (println \"Hello\" user))]
+  (dotimes [_ (add 6 8)]
+    (hello \"John Doe\")))"
+     (2 6 font-lock-keyword-face)
+     (10 12 font-lock-function-name-face)
+     (48 52 font-lock-function-name-face))
+
+    ("(reify
+  AutoCloseable
+  (close [this] (.close this)))"
+     (2 6 font-lock-keyword-face)
+     (27 31 font-lock-function-name-face))
+
+    ("(defrecord TestRecord [field]
+  AutoCloseable
+  (close [this]
+    (.close this)))"
+     (2 10 font-lock-keyword-face)
+     (12 21 font-lock-type-face)
+     (50 54 font-lock-function-name-face))
+
+    ("(definterface MyInterface
+  (^String name [])
+  (^double mass []))"
+     (2 13 font-lock-keyword-face)
+     (15 25 font-lock-type-face)
+     (31 36 font-lock-type-face)
+     (38 41 font-lock-function-name-face)
+     (51 56 font-lock-type-face)
+     (58 61 font-lock-function-name-face))
+
+    ("(deftype ImageSelection [data]
+  Transferable
+  (getTransferDataFlavors
+    [this]
+    (into-array DataFlavor [DataFlavor/imageFlavor])))"
+     (2 8 font-lock-keyword-face)
+     (10 23 font-lock-type-face)
+     (50 71 font-lock-function-name-face))
+
+    ("(defprotocol P
+  (foo [this])
+  (bar-me [this] [this y]))"
+     (2 12 font-lock-keyword-face)
+     (14 14 font-lock-type-face)
+     (19 21 font-lock-function-name-face)
+     (34 39 font-lock-function-name-face))))

test/samples/test.clj

@@ -27,6 +27,14 @@
 (clojure.core/for [])
 (honey.sql/for {})
 
+;; the "add" and "hello" should both have a function name face
+(letfn [(add [x y]
+          (+ x y))
+        (hello [user]
+          (println "Hello" user))]
+  (dotimes [_ (add 6 8)]
+    (hello "John Doe")))
+
 ;; the myfn sexp should have a comment face
 (mysfn 101
        foo