Finish filter-only feature by fixing empty excerpts

pagefind/features/filtering.feature

@@ -159,6 +159,28 @@ Feature: Filtering
         Then There should be no logs
         Then The selector "[data-results]" should contain "/cheeka/, /theodore/"
 
+    Scenario: Filtering without search term returns an unprocessed excerpt
+        When I evaluate:
+            """
+            async function() {
+                let pagefind = await import("/_pagefind/pagefind.js");
+
+                // Run a search so that some index words are loaded
+                let unused = await pagefind.search("cat");
+
+                let search = await pagefind.search(null, {
+                    filters: {
+                        color: ["Black", "White"]
+                    }
+                });
+                let data = await Promise.all(search.results.map(result => result.data()));
+
+                document.querySelector('[data-results]').innerText = data.map(d => d.excerpt).join(', ');
+            }
+            """
+        Then There should be no logs
+        Then The selector "[data-results]" should contain "Black White Cat."
+
     @skip
     # Currently only an AND filtering is supported. Need to restructure to support boolean logic
     Scenario: Filtering to multiple values

pagefind_web/src/lib.rs

@@ -120,7 +120,7 @@ pub fn add_synthetic_filter(ptr: *mut SearchIndex, filter: &str) -> *mut SearchI
 #[wasm_bindgen]
 pub fn request_indexes(ptr: *mut SearchIndex, query: &str) -> String {
     let indexes = try_request_indexes(ptr, query, false);
-    if indexes.is_empty() {
+    if indexes.is_empty() && !query.trim().is_empty() {
         debug!({
             "No index chunks found with strict boundaries. Loading all possible extension chunks."
         });

pagefind_web/src/search.rs

@@ -210,6 +210,9 @@ impl SearchIndex {
 }
 
 fn stems_from_term(term: &str) -> Vec<Cow<str>> {
+    if term.trim().is_empty() {
+        return vec![];
+    }
     let stemmer = Stemmer::try_create_default();
     term.split(' ')
         .map(|word| match &stemmer {