| 1 | package sheets |
| 2 | |
| 3 | import ( |
| 4 | "bufio" |
| 5 | "context" |
| 6 | "fmt" |
| 7 | "io" |
| 8 | "net/http" |
| 9 | "net/http/httptest" |
| 10 | "strings" |
| 11 | "testing" |
| 12 | "time" |
| 13 | ) |
| 14 | |
| 15 | // liveServer starts a real HTTP server for the app. |
| 16 | // |
| 17 | // httptest.ResponseRecorder cannot test this: it buffers everything and |
| 18 | // returns when the handler does, so a handler that built its whole body |
| 19 | // and returned would pass every assertion a recorder can make — while |
| 20 | // being exactly the bug this endpoint must not have. |
| 21 | func liveServer(t *testing.T, app *App) *httptest.Server { |
| 22 | t.Helper() |
| 23 | srv := httptest.NewServer(app.Router()) |
| 24 | t.Cleanup(srv.Close) |
| 25 | return srv |
| 26 | } |
| 27 | |
| 28 | // openStream connects to a tab's stream and returns the response. |
| 29 | func openStream(t *testing.T, srv *httptest.Server, s SheetSummary, cookies []*http.Cookie) *http.Response { |
| 30 | t.Helper() |
| 31 | ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second) |
| 32 | t.Cleanup(cancel) |
| 33 | |
| 34 | url := fmt.Sprintf("%s/api/sheets/%d/tabs/%d/stream", srv.URL, s.ID, s.TabID) |
| 35 | req, err := http.NewRequestWithContext(ctx, http.MethodGet, url, nil) |
| 36 | if err != nil { |
| 37 | t.Fatalf("build stream request: %v", err) |
| 38 | } |
| 39 | for _, c := range cookies { |
| 40 | req.AddCookie(c) |
| 41 | } |
| 42 | resp, err := http.DefaultClient.Do(req) |
| 43 | if err != nil { |
| 44 | t.Fatalf("open stream: %v", err) |
| 45 | } |
| 46 | t.Cleanup(func() { resp.Body.Close() }) |
| 47 | return resp |
| 48 | } |
| 49 | |
| 50 | // readEventWithin reads SSE lines until a data line arrives, or fails. |
| 51 | func readEventWithin(t *testing.T, body io.Reader, d time.Duration) string { |
| 52 | t.Helper() |
| 53 | type result struct{ line string } |
| 54 | ch := make(chan result, 1) |
| 55 | go func() { |
| 56 | sc := bufio.NewScanner(body) |
| 57 | for sc.Scan() { |
| 58 | if strings.HasPrefix(sc.Text(), "data: ") { |
| 59 | ch <- result{sc.Text()} |
| 60 | return |
| 61 | } |
| 62 | } |
| 63 | ch <- result{""} |
| 64 | }() |
| 65 | select { |
| 66 | case r := <-ch: |
| 67 | if r.line == "" { |
| 68 | t.Fatal("the stream ended without sending a data line") |
| 69 | } |
| 70 | return r.line |
| 71 | case <-time.After(d): |
| 72 | t.Fatalf("no event within %s", d) |
| 73 | return "" |
| 74 | } |
| 75 | } |
| 76 | |
| 77 | // Spec §7: the SSE transport check is a streamed 200, not a 101. SSE is |
| 78 | // text/event-stream over a normal response; 101 is the WebSocket |
| 79 | // upgrade, and a check written against 101 would never pass. |
| 80 | func TestStreamIsAStreamed200NotAnUpgrade(t *testing.T) { |
| 81 | app, cookies := signIn(t) |
| 82 | s, _ := newSheet(t, app, cookies, "Budget") |
| 83 | srv := liveServer(t, app) |
| 84 | |
| 85 | resp := openStream(t, srv, s, cookies) |
| 86 | if resp.StatusCode != http.StatusOK { |
| 87 | t.Fatalf("stream = %d, want a streamed 200", resp.StatusCode) |
| 88 | } |
| 89 | if ct := resp.Header.Get("Content-Type"); !strings.HasPrefix(ct, "text/event-stream") { |
| 90 | t.Fatalf("Content-Type = %q, want text/event-stream", ct) |
| 91 | } |
| 92 | // The header that stops an edge buffering a stream into a complete |
| 93 | // response — the failure that turns live sync into "everything |
| 94 | // arrives when you close the tab", and which no in-process test can |
| 95 | // otherwise see. |
| 96 | if got := resp.Header.Get("X-Accel-Buffering"); got != "no" { |
| 97 | t.Errorf("X-Accel-Buffering = %q, want %q", got, "no") |
| 98 | } |
| 99 | } |
| 100 | |
| 101 | // The real assertion: an edit made after the stream was opened arrives |
| 102 | // on it, without the response having to end. A handler that builds its |
| 103 | // body and returns passes every status check above and is useless. |
| 104 | func TestAnEditArrivesOnAnOpenStream(t *testing.T) { |
| 105 | app, cookies := signIn(t) |
| 106 | s, cells := newSheet(t, app, cookies, "Budget") |
| 107 | srv := liveServer(t, app) |
| 108 | |
| 109 | resp := openStream(t, srv, s, cookies) |
| 110 | |
| 111 | // Wait until the handler has actually subscribed. Posting before |
| 112 | // that races the subscription and loses the message — the test |
| 113 | // would be flaky rather than wrong, which is worse. |
| 114 | waitForSubscriber(t, app, s.TabID) |
| 115 | |
| 116 | postCell(t, app, cookies, cells, `{"r":0,"c":0,"raw":"=6*7"}`) |
| 117 | |
| 118 | line := readEventWithin(t, resp.Body, 5*time.Second) |
| 119 | if !strings.Contains(line, `"display":"42"`) { |
| 120 | t.Fatalf("first streamed event = %q, want the computed value", line) |
| 121 | } |
| 122 | } |
| 123 | |
| 124 | // Two tabs on one sheet: the whole feature, at the layer below the |
| 125 | // browser. |
| 126 | func TestTwoStreamsBothReceiveAnEdit(t *testing.T) { |
| 127 | app, cookies := signIn(t) |
| 128 | s, cells := newSheet(t, app, cookies, "Budget") |
| 129 | srv := liveServer(t, app) |
| 130 | |
| 131 | first := openStream(t, srv, s, cookies) |
| 132 | second := openStream(t, srv, s, cookies) |
| 133 | waitForSubscriberCount(t, app, s.TabID, 2) |
| 134 | |
| 135 | postCell(t, app, cookies, cells, `{"r":0,"c":0,"raw":"hello"}`) |
| 136 | |
| 137 | for i, resp := range []*http.Response{first, second} { |
| 138 | if line := readEventWithin(t, resp.Body, 5*time.Second); !strings.Contains(line, "hello") { |
| 139 | t.Errorf("stream %d received %q", i, line) |
| 140 | } |
| 141 | } |
| 142 | } |
| 143 | |
| 144 | func TestStreamOfAnUnknownTabIs404(t *testing.T) { |
| 145 | app, cookies := signIn(t) |
| 146 | s, _ := newSheet(t, app, cookies, "Budget") |
| 147 | |
| 148 | path := fmt.Sprintf("/api/sheets/%d/tabs/999999/stream", s.ID) |
| 149 | if rec := do(t, app, as(httptest.NewRequest(http.MethodGet, path, nil), cookies)); rec.Code != http.StatusNotFound { |
| 150 | t.Fatalf("streaming an unknown tab = %d, want 404", rec.Code) |
| 151 | } |
| 152 | } |
| 153 | |
| 154 | func TestStreamRequiresASession(t *testing.T) { |
| 155 | app, cookies := signIn(t) |
| 156 | s, _ := newSheet(t, app, cookies, "Budget") |
| 157 | |
| 158 | path := fmt.Sprintf("/api/sheets/%d/tabs/%d/stream", s.ID, s.TabID) |
| 159 | if rec := do(t, app, httptest.NewRequest(http.MethodGet, path, nil)); rec.Code == http.StatusOK { |
| 160 | t.Fatal("the stream served a request with no session") |
| 161 | } |
| 162 | } |
| 163 | |
| 164 | // Closing the connection must unsubscribe, or an instance leaks one |
| 165 | // subscription per browser tab that has ever been opened. |
| 166 | func TestClosingAStreamUnsubscribes(t *testing.T) { |
| 167 | app, cookies := signIn(t) |
| 168 | s, _ := newSheet(t, app, cookies, "Budget") |
| 169 | srv := liveServer(t, app) |
| 170 | |
| 171 | resp := openStream(t, srv, s, cookies) |
| 172 | waitForSubscriber(t, app, s.TabID) |
| 173 | resp.Body.Close() |
| 174 | |
| 175 | deadline := time.Now().Add(5 * time.Second) |
| 176 | for time.Now().Before(deadline) { |
| 177 | if app.hub.Subscribers(s.TabID) == 0 { |
| 178 | return |
| 179 | } |
| 180 | time.Sleep(10 * time.Millisecond) |
| 181 | } |
| 182 | t.Fatalf("after the client closed, %d subscribers remain", app.hub.Subscribers(s.TabID)) |
| 183 | } |
| 184 | |
| 185 | func waitForSubscriber(t *testing.T, app *App, tabID uint64) { |
| 186 | t.Helper() |
| 187 | waitForSubscriberCount(t, app, tabID, 1) |
| 188 | } |
| 189 | |
| 190 | func waitForSubscriberCount(t *testing.T, app *App, tabID uint64, want int) { |
| 191 | t.Helper() |
| 192 | deadline := time.Now().Add(5 * time.Second) |
| 193 | for time.Now().Before(deadline) { |
| 194 | if app.hub.Subscribers(tabID) >= want { |
| 195 | return |
| 196 | } |
| 197 | time.Sleep(5 * time.Millisecond) |
| 198 | } |
| 199 | t.Fatalf("only %d subscribers on tab %d after 5s, want %d", |
| 200 | app.hub.Subscribers(tabID), tabID, want) |
| 201 | } |
| 202 | |
amadan