diff --git a/web/test/crate_test.gleam b/web/test/crate_test.gleam
index f2aec25..49394b5 100644
--- a/web/test/crate_test.gleam
+++ b/web/test/crate_test.gleam
@@ -125,8 +125,6 @@ pub fn set_display_back_to_grid_persists_without_a_shelf_reload_test() {
   let rows_view = Model(..logged_in(), display: Rows)
   let #(model, effect) = update(rows_view, SetDisplay(Grid))
   assert model.display == Grid
-  // Switching display persists the choice (see prefs_test.gleam) but never
-  // reloads the shelf.
   assert effect != empty_effect()
 }
 
diff --git a/web/test/prefs_test.gleam b/web/test/prefs_test.gleam
index 2f826b1..6d38b44 100644
--- a/web/test/prefs_test.gleam
+++ b/web/test/prefs_test.gleam
@@ -1,9 +1,5 @@
-//// Interface-level tests for the generic prefs module's pure helpers (JSON
-//// codecs, capping, dedup) and for the `update`/init integration points
-//// that read/write them. The FFI boundary itself (`prefs.get`/`prefs.set`,
-//// backed by localStorage) is a thin, side-effecting passthrough exercised
-//// in the browser, not here - `update` never runs its own effects, so these
-//// tests never touch real localStorage.
+//// Tests for the prefs module's pure helpers and the `update` integration
+//// that persists/loads them.
 
 import at_record_web/model.{
   type EditProposal, EditProposal, Grid, InboxCard, InboxLoaded, Model,
@@ -45,19 +41,21 @@ fn a_proposal(uri: String, cid: String) -> EditProposal {
 
 // --- display ---
 
-pub fn display_to_string_round_trips_test() {
-  assert model.display_from_string(model.display_to_string(Grid)) == Grid
-  assert model.display_from_string(model.display_to_string(Rows)) == Rows
+pub fn display_string_codec_test() {
+  [#(Grid, "grid"), #(Rows, "rows")]
+  |> list.each(fn(pair) {
+    let #(display, str) = pair
+    assert model.display_to_string(display) == str
+    assert model.display_from_string(str) == display
+  })
+  ["", "garbage"]
+  |> list.each(fn(value) {
+    assert model.display_from_string(value) == Grid
+  })
 }
 
-pub fn display_from_string_falls_back_to_grid_for_unknown_values_test() {
-  assert model.display_from_string("") == Grid
-  assert model.display_from_string("garbage") == Grid
-}
-
-pub fn set_display_persists_and_updates_the_model_test() {
-  let #(model_after, effect) = update(logged_in(), SetDisplay(Rows))
-  assert model_after.display == Rows
+pub fn set_display_fires_a_persist_effect_test() {
+  let #(_, effect) = update(logged_in(), SetDisplay(Rows))
   assert effect != empty_effect()
 }
 
@@ -71,8 +69,10 @@ pub fn ignored_proposals_round_trip_through_json_test() {
 }
 
 pub fn ignored_proposals_decode_falls_back_to_empty_on_garbage_test() {
-  assert prefs.decode_ignored_proposals("not json") == []
-  assert prefs.decode_ignored_proposals("{}") == []
+  ["not json", "{}"]
+  |> list.each(fn(raw) {
+    assert prefs.decode_ignored_proposals(raw) == []
+  })
 }
 
 pub fn add_ignored_proposal_dedupes_on_uri_test() {