SEO-13: no JobPosting on the jobs listing; a job's page carries one (#114)

ddiff --git a/test/jobs.test.js b/test/jobs.test.js
iindex bf10d64..05499f9 100644
---- a/test/jobs.test.js
++++ b/test/jobs.test.js
@@@ -139,6 +139,7 @@ const first = async (t, path) => (await t.get(path)).json();
          await check('the listing page carries a valid JobPosting whose url is the original, not this page', async () => {
              const job = (await first(t, '/api/v1/jobs?q=DevOps')).jobs[0];
              const html = (await t.get(`/jobs/${job.id}`)).text;
++            assert.strictEqual((html.match(/application\/ld\+json/g) || []).length, 1, 'one JSON-LD script per page');
              const blocks = ldBlocks(html);
              const posting = blocks.find((b) => b['@type'] === 'JobPosting');
              assert.ok(posting, `no JobPosting node: ${JSON.stringify(blocks.map((b) => b['@type']))}`);
@@@ -151,6 +152,8 @@ const first = async (t, path) => (await t.get(path)).json();
              assert.strictEqual(posting.identifier.name, 'remoteok');
              assert.ok(posting.description.length <= 320);
              assert.ok(posting['@context'] === 'https://schema.org');
++            // The search page lists many listings but is not one job, so it carries no JobPosting.
++            assert.ok(!ldBlocks((await t.get('/jobs')).text).some((b) => b['@type'] === 'JobPosting'), 'the listing page has no JobPosting');
              // Every JSON-LD block on the page parses (the escaping must survive a hostile title).
              assert.ok(blocks.length >= 1);
          });