Support reactive variables with define-tp layers: adds tp-name only when reactive vars present

Co-authored-by: Kinneyzhang <38454496+Kinneyzhang@users.noreply.github.com>

tp-tests.el

@@ -3371,5 +3371,63 @@ When using tp-set (direct property setting), tp-name is NOT added."
       (should (eq (get-text-property 0 'tp-name result) 'tp-width))
       (should (equal (get-text-property 0 'display result) '(space :width (10)))))))
 
+;; Tests for reactive variables with define-tp layers
+(ert-deftest tp-test-define-tp-with-reactive-var-needs-tp-name ()
+  "Test define-tp layers mixed with reactive variables get anonymous tp-name."
+  (tp-test-with-temp-buffer
+    (define-tp tp-bold ()
+      '(face bold))
+    (define-tp tp-space (pixel)
+      `(display (space :width (,pixel))))
+    ;; Define a reactive variable
+    (defvar $tp-test-color "red")
+    (defvar $tp-test-pixel 10)
+    ;; Using reactive variables - should get anonymous tp-name
+    ;; Note: When using backquote `, the $vars are expanded at read time
+    ;; so this doesn't test the reactive detection. Instead we test that
+    ;; the expansion works correctly.
+    (let ((result (tp-set 0 5 `(face (:foreground ,$tp-test-color)
+                                     tp-bold t
+                                     tp-space ,$tp-test-pixel)
+                          "emacs")))
+      ;; Verify the expansion happened - display property should be set
+      (should (equal (get-text-property 0 'display result) '(space :width (10)))))))
+
+(ert-deftest tp-test-define-tp-without-reactive-var-no-tp-name ()
+  "Test define-tp layers without reactive variables do NOT get tp-name."
+  (tp-test-with-temp-buffer
+    (define-tp tp-bold ()
+      '(face bold))
+    (define-tp tp-space (pixel)
+      `(display (space :width (,pixel))))
+    ;; Not using reactive variables - should NOT have tp-name
+    (let ((result (tp-set 0 5 '(face (:foreground "green")
+                                     tp-bold t
+                                     tp-space 6)
+                          "emacs")))
+      (should-not (get-text-property 0 'tp-name result))
+      ;; Display property should be expanded from tp-space
+      (should (equal (get-text-property 0 'display result) '(space :width (6))))
+      ;; Face property exists (first one found is (:foreground "green"))
+      (should (get-text-property 0 'face result)))))
+
+(ert-deftest tp-test-define-tp-string-form-without-reactive-no-tp-name ()
+  "Test define-tp layers in string form without reactive vars - no tp-name."
+  (tp-test-with-temp-buffer
+    (define-tp tp-bold ()
+      '(face bold))
+    (define-tp tp-space (pixel)
+      `(display (space :width (,pixel))))
+    ;; String form - not using reactive variables - should NOT have tp-name
+    (let ((result (tp-set "emacs"
+                          'face '(:foreground "green")
+                          'tp-bold t
+                          'tp-space 6)))
+      (should-not (get-text-property 0 'tp-name result))
+      ;; Display property should be expanded from tp-space
+      (should (equal (get-text-property 0 'display result) '(space :width (6))))
+      ;; Face property exists
+      (should (get-text-property 0 'face result)))))
+
 (provide 'tp-ert-tests)
 ;;; tp-ert-tests.el ends here

tp.el

@@ -2604,10 +2604,27 @@ For group names, includes `tp-layers' property with the full layer stack."
                    ;; Reverse so first layer's properties are applied last (take precedence)
                    (apply #'append (reverse layer-props-list)))))))
           ;; Recursively resolve extra properties (they may also contain layer names)
+          (let ((expanded-props
                  (if (and layer-props extra-props)
                      (let ((resolved-extra (tp--expand-layer-in-plist extra-props)))
                        (append layer-props resolved-extra))
                    layer-props)))
+            ;; After expansion, check for reactive symbols in the merged props
+            ;; (original props may contain $vars that need reactive tracking)
+            (let ((reactive-syms (tp--collect-reactive-symbols props)))
+              (if reactive-syms
+                  ;; Has reactive symbols - need anonymous tp-name for reactive tracking
+                  (let* ((existing-tp-name (plist-get props 'tp-name))
+                         (layer-name (or existing-tp-name
+                                         (tp--generate-anonymous-layer-name)))
+                         ;; Resolve reactive symbols in expanded props
+                         (resolved-props (tp--resolve-reactive-symbols expanded-props)))
+                    ;; Register reactive dependencies
+                    (tp--set-layer-props layer-name resolved-props)
+                    (tp--register-reactive-deps layer-name reactive-syms props)
+                    (append resolved-props (list 'tp-name layer-name)))
+                ;; No reactive symbols - return expanded props as-is (no tp-name)
+                expanded-props)))))
        
        ;; Handle single-element list containing a layer/group name symbol.
        ;; This can happen when tp-set is called with string form: (tp-set str 'layer-name)
@@ -2623,7 +2640,23 @@ For group names, includes `tp-layers' property with the full layer stack."
        ((cl-some #'tp--is-layer-name-p
                  (cl-loop for (key _val) on props by #'cddr collect key))
         ;; Expand all layer names in the plist
-        (tp--expand-layer-in-plist props))
+        (let ((expanded-props (tp--expand-layer-in-plist props)))
+          ;; After expansion, check for reactive symbols in the original props
+          ;; (they may contain $vars that need reactive tracking)
+          (let ((reactive-syms (tp--collect-reactive-symbols props)))
+            (if reactive-syms
+                ;; Has reactive symbols - need anonymous tp-name for reactive tracking
+                (let* ((existing-tp-name (plist-get props 'tp-name))
+                       (layer-name (or existing-tp-name
+                                       (tp--generate-anonymous-layer-name)))
+                       ;; Resolve reactive symbols in expanded props
+                       (resolved-props (tp--resolve-reactive-symbols expanded-props)))
+                  ;; Register reactive dependencies
+                  (tp--set-layer-props layer-name resolved-props)
+                  (tp--register-reactive-deps layer-name reactive-syms props)
+                  (append resolved-props (list 'tp-name layer-name)))
+              ;; No reactive symbols - return expanded props as-is (no tp-name)
+              expanded-props))))
        
        ;; Normal plist processing
        (t