feat: Return publicly shared document title in SSR HTML (#2191)

* feat: Return publicly shared document title in SSR HTML
closes #2146

* tests

server/app.test.js

@@ -0,0 +1,52 @@
+// @flow
+import TestServer from "fetch-test-server";
+import app from "./app";
+import { buildShare, buildDocument } from "./test/factories";
+import { flushdb } from "./test/support";
+
+const server = new TestServer(app.callback());
+
+beforeEach(() => flushdb());
+afterAll(() => server.close());
+
+describe("/share/:id", () => {
+  it("should return standard title in html when loading share", async () => {
+    const share = await buildShare({ published: false });
+
+    const res = await server.get(`/share/${share.id}`);
+    const body = await res.text();
+
+    expect(res.status).toEqual(200);
+    expect(body).toContain("<title>Outline</title>");
+  });
+
+  it("should return standard title in html when share does not exist", async () => {
+    const res = await server.get(`/share/junk`);
+    const body = await res.text();
+
+    expect(res.status).toEqual(200);
+    expect(body).toContain("<title>Outline</title>");
+  });
+
+  it("should return document title in html when loading published share", async () => {
+    const document = await buildDocument();
+    const share = await buildShare({ documentId: document.id });
+
+    const res = await server.get(`/share/${share.id}`);
+    const body = await res.text();
+
+    expect(res.status).toEqual(200);
+    expect(body).toContain(`<title>${document.title}</title>`);
+  });
+
+  it("should return document title in html when loading published share with nested doc route", async () => {
+    const document = await buildDocument();
+    const share = await buildShare({ documentId: document.id });
+
+    const res = await server.get(`/share/${share.id}/doc/test-Cl6g1AgPYn`);
+    const body = await res.text();
+
+    expect(res.status).toEqual(200);
+    expect(body).toContain(`<title>${document.title}</title>`);
+  });
+});