fix(view-sync): refuse sync of a saved query whose filter is empty

A saved query with no filter constraints compiled to nil via pearl--build-issue-filter. The sync command then passed (cons "filterData" nil) to customViewCreate, which JSON-encoded as filterData=null. Linear's CustomViewCreateInput.filterData expects a JSON object, so the API rejected with an opaque error message after the user had already clicked through the scope picker.

I added an early refusal in pearl-sync-saved-query-to-linear: when filter-data is nil, signal a user-error naming what's wrong before the scope prompt fires. The message tells the user to add a constraint and re-sync rather than leaving them to puzzle out an opaque API rejection.

I restructured the let* nesting to put the empty-filter check between the bindings (where filter-data is computed) and the scope prompt (where the user is asked to pick a destination). The scope binding moved out of the outer let* into an inner let so it doesn't evaluate until after the filter-data guard runs.

Two tests cover the guard. The first-time-sync test (no :linear-view-id on the entry) asserts neither the scope prompt nor customViewCreate fires. The re-sync test (entry has :linear-view-id) asserts customViewUpdate doesn't fire either. The re-sync test guards against a future refactor accidentally hoisting the check into the create-only branch. All 663 ert tests pass. make compile and make lint are clean.

2 files changed, 56 insertions, 27 deletions

diff --git a/pearl.el b/pearl.el
index 39b7878..ad88d4d 100644
--- a/pearl.el
+++ b/pearl.el
@@ -3953,32 +3953,41 @@ the user can re-sync with Replace to reconcile."
            ;; silently flip a personal view to team-shared.
            (existing-shared (eq (plist-get spec :linear-view-shared) t))
            (filter-data (pearl--build-issue-filter filter-plist))
-           (target-name name)
-           (scope (if existing-view-id
-                      ;; Re-sync uses the stored scope.
-                      (list :team-id existing-team-id
-                            :team-name (or (and existing-team-id
-                                                (cdr (assoc 'name
-                                                            (seq-find
-                                                             (lambda (tm)
-                                                               (equal existing-team-id
-                                                                      (cdr (assoc 'id tm))))
-                                                             (pearl--all-teams)))))
-                                           "Personal")
-                            :shared existing-shared)
-                    (pearl--sync-saved-query-pick-scope filter-plist))))
-      (unless scope
-        (user-error "Cancelled; no saved query synced"))
-      ;; Validate the filter at the boundary so a malformed entry surfaces
-      ;; before the API call.
-      (pearl--validate-issue-filter filter-plist)
-      (let* ((team-id (plist-get scope :team-id))
-             (shared (plist-get scope :shared))
-             (scope-label (car (rassoc scope
-                                       (pearl--sync-scope-candidates
-                                        (pearl--all-teams)
-                                        (plist-get filter-plist :team))))))
-        (cond
+           (target-name name))
+      ;; Linear's CustomViewCreateInput.filterData expects a JSON object.  An
+      ;; empty filter plist compiles to nil, which JSON-encodes as `null' and
+      ;; the API rejects with an opaque error.  Refuse early -- before we
+      ;; prompt the user for scope -- so they see what's wrong instead of
+      ;; clicking through the scope picker only to hit "Linear refused".
+      (unless filter-data
+        (user-error
+         "Saved query %s has no filter constraints; Linear views need at least one constraint -- add one and re-sync"
+         name))
+      (let ((scope (if existing-view-id
+                       ;; Re-sync uses the stored scope.
+                       (list :team-id existing-team-id
+                             :team-name (or (and existing-team-id
+                                                 (cdr (assoc 'name
+                                                             (seq-find
+                                                              (lambda (tm)
+                                                                (equal existing-team-id
+                                                                       (cdr (assoc 'id tm))))
+                                                              (pearl--all-teams)))))
+                                            "Personal")
+                             :shared existing-shared)
+                     (pearl--sync-saved-query-pick-scope filter-plist))))
+        (unless scope
+          (user-error "Cancelled; no saved query synced"))
+        ;; Validate the filter at the boundary so a malformed entry surfaces
+        ;; before the API call.
+        (pearl--validate-issue-filter filter-plist)
+        (let* ((team-id (plist-get scope :team-id))
+               (shared (plist-get scope :shared))
+               (scope-label (car (rassoc scope
+                                         (pearl--sync-scope-candidates
+                                          (pearl--all-teams)
+                                          (plist-get filter-plist :team))))))
+          (cond
          ;; First-time sync: check for a same-name collision in the chosen
          ;; scope and either update-by-id (Replace), re-prompt (Rename), or
          ;; bail (Cancel).
@@ -4011,7 +4020,7 @@ the user can re-sync with Replace to reconcile."
          ;; the existing view directly).
          (t
           (pearl--sync-saved-query-do-update
-           name existing-view-id team-id shared filter-data scope-label)))))))
+           name existing-view-id team-id shared filter-data scope-label))))))))
 
 (defun pearl--sync-saved-query-do-create (name target-name team-id shared
                                                filter-data scope-label)
diff --git a/tests/test-pearl-saved-query-sync.el b/tests/test-pearl-saved-query-sync.el
index ceac5e6..8c98539 100644
--- a/tests/test-pearl-saved-query-sync.el
+++ b/tests/test-pearl-saved-query-sync.el
@@ -415,6 +415,26 @@ erased on every re-sync."
       (let ((shared-value (cdr (assoc "shared" captured-input))))
         (should (eq :json-false shared-value))))))
 
+;;; pearl-sync-saved-query-to-linear — empty filter refusal
+
+(ert-deftest test-pearl-sync-empty-filter-refuses-before-scope-prompt ()
+  "A saved query whose filter compiles to nil signals a clear user-error
+before any scope prompt fires.  Without the guard, the sync would pass
+filterData=null to Linear, which rejects with an opaque error after the
+user has already clicked through the scope picker."
+  (let ((pearl-saved-queries (copy-tree '(("EmptyFilter" :filter nil))))
+        (scope-prompt-fired nil)
+        (api-called nil))
+    (cl-letf (((symbol-function 'pearl--sync-saved-query-pick-scope)
+               (lambda (&rest _) (setq scope-prompt-fired t)
+                 (list :team-id nil :team-name "Personal" :shared nil)))
+              ((symbol-function 'pearl--customview-create-async)
+               (lambda (&rest _) (setq api-called t))))
+      (should-error (pearl-sync-saved-query-to-linear "EmptyFilter")
+                    :type 'user-error)
+      (should-not scope-prompt-fired)
+      (should-not api-called))))
+
 ;;; pearl-publish-current-source
 
 (defmacro test-pearl-publish--in-buffer (source-form &rest body)