fix: Preserve tp-name and tp-layers when setting properties with layer/group names

- tp--resolve-props now uses tp-layer-props (includes tp-name) for layers
- For groups, uses tp--build-layer-props to include tp-layers structure
- Updated tests to verify tp-name and tp-layers are preserved
- Added new test for groups with multiple layers

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

tp-tests.el

@@ -2054,7 +2054,9 @@ Returns list of (START END VALUE) intervals."
     ;; Use layer name instead of plist
     (tp-set 1 6 'my-style)
     (should (eq (tp-at 1 'face) 'bold))
-    (should (equal (tp-at 1 'help-echo) "tip"))))
+    (should (equal (tp-at 1 'help-echo) "tip"))
+    ;; tp-name should be preserved for reactive text property support
+    (should (eq (tp-at 1 'tp-name) 'my-style))))
 
 (ert-deftest tp-test-set-with-layer-name-on-string ()
   "Test tp-set accepts a layer name on string."
@@ -2063,7 +2065,9 @@ Returns list of (START END VALUE) intervals."
     (setq tp-layer-groups nil)
     (tp-define-layer my-style (face italic))
     (tp-set 0 5 'my-style str)
-    (should (eq (get-text-property 0 'face str) 'italic))))
+    (should (eq (get-text-property 0 'face str) 'italic))
+    ;; tp-name should be preserved for reactive text property support
+    (should (eq (get-text-property 0 'tp-name str) 'my-style))))
 
 (ert-deftest tp-test-reset-with-layer-name ()
   "Test tp-reset accepts a layer name defined by define-tp."
@@ -2074,7 +2078,9 @@ Returns list of (START END VALUE) intervals."
     ;; Use layer name - should completely replace
     (tp-reset 1 6 'my-style)
     (should (eq (tp-at 1 'face) 'underline))
-    (should (null (tp-at 1 'mouse-face)))))
+    (should (null (tp-at 1 'mouse-face)))
+    ;; tp-name should be preserved
+    (should (eq (tp-at 1 'tp-name) 'my-style))))
 
 (ert-deftest tp-test-add-with-layer-name ()
   "Test tp-add accepts a layer name defined by define-tp."
@@ -2085,7 +2091,9 @@ Returns list of (START END VALUE) intervals."
     ;; Use layer name - should preserve existing properties
     (tp-add 1 6 'my-style)
     (should (eq (tp-at 1 'face) 'bold))
-    (should (equal (tp-at 1 'help-echo) "existing"))))
+    (should (equal (tp-at 1 'help-echo) "existing"))
+    ;; tp-name should be preserved
+    (should (eq (tp-at 1 'tp-name) 'my-style))))
 
 (ert-deftest tp-test-match-set-with-layer-name ()
   "Test tp-match-set accepts a layer name."
@@ -2095,7 +2103,9 @@ Returns list of (START END VALUE) intervals."
     (tp-match-set "Hello" 'match-style)
     (should (eq (tp-at 1 'face) 'bold))
     (should (equal (tp-at 1 'help-echo) "matched"))
-    (should (eq (tp-at 13 'face) 'bold))))
+    (should (eq (tp-at 13 'face) 'bold))
+    ;; tp-name should be preserved
+    (should (eq (tp-at 1 'tp-name) 'match-style))))
 
 (ert-deftest tp-test-match-set-with-layer-name-on-string ()
   "Test tp-match-set accepts a layer name on string."
@@ -2105,7 +2115,9 @@ Returns list of (START END VALUE) intervals."
     (tp-define-layer match-style (face italic))
     (tp-match-set "Hello" 'match-style str)
     (should (eq (get-text-property 0 'face str) 'italic))
-    (should (eq (get-text-property 12 'face str) 'italic))))
+    (should (eq (get-text-property 12 'face str) 'italic))
+    ;; tp-name should be preserved
+    (should (eq (get-text-property 0 'tp-name str) 'match-style))))
 
 (ert-deftest tp-test-match-reset-with-layer-name ()
   "Test tp-match-reset accepts a layer name."
@@ -2165,7 +2177,9 @@ Returns list of (START END VALUE) intervals."
     (tp-define-layer number-style (face bold))
     (tp-regexp-add "[0-9]+" 'number-style)
     (should (eq (tp-at 5 'face) 'bold))
-    (should (equal (tp-at 5 'help-echo) "original"))))
+    (should (equal (tp-at 5 'help-echo) "original"))
+    ;; tp-name should be preserved
+    (should (eq (tp-at 5 'tp-name) 'number-style))))
 
 (ert-deftest tp-test-set-with-group-name ()
   "Test tp-set accepts a group name defined by define-tp-group."
@@ -2173,10 +2187,30 @@ Returns list of (START END VALUE) intervals."
     (insert "Hello World")
     (tp-define-layer-group my-group
       ("style" . (face bold help-echo "grouped")))
-    ;; Use group name - should use first layer's properties
+    ;; Use group name - should include tp-name for top layer
     (tp-set 1 6 'my-group)
     (should (eq (tp-at 1 'face) 'bold))
-    (should (equal (tp-at 1 'help-echo) "grouped"))))
+    (should (equal (tp-at 1 'help-echo) "grouped"))
+    ;; tp-name should be preserved for the top layer
+    (should (eq (tp-at 1 'tp-name) 'my-group-style))))
+
+(ert-deftest tp-test-set-with-group-name-multiple-layers ()
+  "Test tp-set with group containing multiple layers preserves tp-layers."
+  (tp-test-with-temp-buffer
+    (insert "Hello World")
+    (tp-define-layer-group my-group
+      ("first" . (face bold))
+      ("second" . (face italic)))
+    ;; Use group name - should include tp-layers for multiple layers
+    (tp-set 1 6 'my-group)
+    ;; First layer is on top
+    (should (eq (tp-at 1 'face) 'bold))
+    (should (eq (tp-at 1 'tp-name) 'my-group-first))
+    ;; tp-layers should contain the second layer
+    (let ((layers (tp-at 1 'tp-layers)))
+      (should layers)
+      (should (= (length layers) 1))
+      (should (eq (plist-get (car layers) 'tp-name) 'my-group-second)))))
 
 (ert-deftest tp-test-match-set-with-group-name ()
   "Test tp-match-set accepts a group name."
@@ -2186,7 +2220,9 @@ Returns list of (START END VALUE) intervals."
       ("style" . (face italic)))
     (tp-match-set "Hello" 'my-group)
     (should (eq (tp-at 1 'face) 'italic))
-    (should (eq (tp-at 13 'face) 'italic))))
+    (should (eq (tp-at 13 'face) 'italic))
+    ;; tp-name should be preserved
+    (should (eq (tp-at 1 'tp-name) 'my-group-style))))
 
 (ert-deftest tp-test-resolve-props-returns-nil-for-unknown ()
   "Test tp--resolve-props returns nil for unknown layer name."

tp.el

@@ -1953,37 +1953,33 @@ Appends 'tp-name property to identify the layer."
             layers)))
 
 (defun tp--resolve-props (props)
-  "Resolve PROPS to a property list.
+  "Resolve PROPS to a property list with layer metadata.
 PROPS can be:
 - A symbol (layer name from `tp-layer-alist' or group name from `tp-layer-groups')
 - A plist (returned as-is)
 
 If PROPS is a symbol:
-- First checks `tp-layer-alist' and returns the layer properties
+- First checks `tp-layer-alist' and returns the layer properties WITH `tp-name'
-- Then checks `tp-layer-groups' and returns the first layer's properties
+- Then checks `tp-layer-groups' and returns properties WITH `tp-layers'
 
-Returns nil if PROPS is a symbol but no matching layer/group is found,
+Returns nil if PROPS is a symbol but no matching layer/group is found.
-or if the group's first layer doesn't exist in `tp-layer-alist'.
 
-Unlike `tp-layer-props', this does NOT add the `tp-name' property,
+For layer names, includes `tp-name' property for reactive text property support.
-making it suitable for use with basic property-setting APIs like
+For group names, includes `tp-layers' property with the full layer stack."
-`tp-set', `tp-add', `tp-match-set', etc."
   (cond
    ;; Already a plist - return as-is
    ((listp props) props)
    ;; Symbol - check if it's a layer or group name
    ((symbolp props)
     (cond
-     ;; Check layer first
+     ;; Check layer first - use tp-layer-props which adds tp-name
      ((assoc props tp-layer-alist)
-      (cdr (assoc props tp-layer-alist)))
+      (tp-layer-props props))
-     ;; Check group (use first layer's properties)
+     ;; Check group - build layer stack with tp-layers
      ((assoc props tp-layer-groups)
-      (when-let* ((layers (cdr (assoc props tp-layer-groups)))
+      (when-let ((layer-props-list (tp-group-props props)))
-                  (first-layer (car layers))
+        ;; Build the layer stack: first layer on top, rest in tp-layers
-                  ;; Ensure the first layer exists in tp-layer-alist
+        (tp--build-layer-props layer-props-list)))
-                  (layer-entry (assoc first-layer tp-layer-alist)))
-        (cdr layer-entry)))
      ;; Not found - return nil (let caller decide how to handle)
      (t nil)))
    (t nil)))