Make sure that the order of the filterableAttributes is constant

meilisearch-http/src/index/updates.rs

@@ -55,7 +55,7 @@ pub struct Settings<T> {
     pub searchable_attributes: Setting<Vec<String>>,
 
     #[serde(default, skip_serializing_if = "Setting::is_not_set")]
-    pub filterable_attributes: Setting<HashSet<String>>,
+    pub filterable_attributes: Setting<BTreeSet<String>>,
     #[serde(default, skip_serializing_if = "Setting::is_not_set")]
     pub sortable_attributes: Setting<BTreeSet<String>>,
     #[serde(default, skip_serializing_if = "Setting::is_not_set")]
@@ -254,7 +254,9 @@ impl Index {
         }
 
         match settings.filterable_attributes {
-            Setting::Set(ref facets) => builder.set_filterable_fields(facets.clone()),
+            Setting::Set(ref facets) => {
+                builder.set_filterable_fields(facets.clone().into_iter().collect())
+            }
             Setting::Reset => builder.reset_filterable_fields(),
             Setting::NotSet => (),
         }

meilisearch-http/src/routes/indexes/settings.rs

@@ -75,7 +75,7 @@ macro_rules! make_setting_route {
 
 make_setting_route!(
     "/filterable-attributes",
-    std::collections::HashSet<String>,
+    std::collections::BTreeSet<String>,
     filterable_attributes,
     "filterableAttributes"
 );