Say "at least" when an API search with no total was cut to fit

src/apisearch.js

@@ -38,18 +38,24 @@ const field = (item, spec) =>
 export function resultsToHTML(def, query, data, apiURL) {
   const host = new URL(apiURL).host;
   const fields = def.fields ?? {};
-  const list = pick(data, def.results ?? 'results');
-  const items = (Array.isArray(list) ? list : []).slice(0, MAX_RESULTS).map((item) => {
+  const picked = pick(data, def.results ?? 'results');
+  const list = Array.isArray(picked) ? picked : [];
+  const items = list.slice(0, MAX_RESULTS).map((item) => {
     const href = new URL(String(field(item, fields.url ?? 'url') ?? ''), apiURL).href;
     const title = String(field(item, fields.title ?? 'title') || href);
     const text = fields.text ? String(field(item, fields.text) ?? '').trim() : '';
     return `<li><a href="${escapeHTML(href)}">${escapeHTML(title)}</a>`
       + `${text ? ` ${escapeHTML(text)}` : ''}</li>`;
   });
   const total = Number(def.total ? pick(data, def.total) : NaN);
-  const count = Number.isFinite(total) && total >= items.length ? total : items.length;
+  // An answer with no total says only how many results it carried, and one
+  // cut to fit is a floor: RubyGems answers 30 a page, so "rails" read as 20
+  // pages matching and nothing saying the list went on.
+  const known = Number.isFinite(total) && total >= items.length;
+  const count = known ? total : list.length;
+  const floor = !known && count > items.length ? 'at least ' : '';
   const summary = items.length
-    ? `${count} page${count === 1 ? '' : 's'} match, ranked by the site's own search`
+    ? `${floor}${count} page${count === 1 ? '' : 's'} match, ranked by the site's own search`
       + `${count > items.length ? `, top ${items.length} shown` : ''}:`
     : `nothing in the site's own search matches; try fewer or different words`;
   return `<html><head><title>${escapeHTML(host)} search: ${escapeHTML(query)}</title></head><body><main>`

tests/apisearch.test.js

@@ -33,6 +33,17 @@ test('the site total is reported, and result count is what the page shows', () =
   assert.match(resultsToHTML(DEF, 'map', DATA, API), /2696 pages match, ranked by the site's own search, top 2 shown:/);
 });
 
+test('with no total, a list cut to fit says it went on', () => {
+  // RubyGems answers a search with a bare array of 30 and no total. Cut to
+  // 20, the page said 20 pages match and nothing about the other ten.
+  const gems = Array.from({ length: 30 }, (_, i) => ({ name: `gem${i}`, url: `https://rubygems.org/gems/gem${i}` }));
+  const def = { results: '', fields: { title: 'name', url: 'url' } };
+  const api = 'https://rubygems.org/api/v1/search.json?query=rails';
+  assert.match(resultsToHTML(def, 'rails', gems, api), /at least 30 pages match, ranked by the site's own search, top 20 shown:/);
+  // A list that fits is still counted as it is.
+  assert.match(resultsToHTML(def, 'rails', gems.slice(0, 5), api), /<p>5 pages match, ranked by the site's own search:<\/p>/);
+});
+
 test('a title is response data, never markup on the results page', () => {
   const html = resultsToHTML(DEF, 'map', DATA, API);
   assert.doesNotMatch(html, /<script/);