limits_test.gno

 1package wiki
 2
 3import (
 4	"strings"
 5	"testing"
 6
 7	"gno.land/p/nt/uassert/v0"
 8)
 9
10// maxLines is how many typical lines fit in DefaultMaxBody: 32 KiB at 43
11// bytes per line.
12const maxLines = 758
13
14func buildLines(n int) string {
15	var b strings.Builder
16	for i := 0; i < n; i++ {
17		b.WriteString("some article line of moderate length here.\n")
18	}
19	return b.String()
20}
21
22// TestWorstCaseRendersStayWithinTheQueryBudget exercises the two render paths
23// at the largest body MaxBody admits.
24//
25// vm/qrender runs under a fixed ceiling (maxGasQuery = 3e9 in
26// gno.land/pkg/sdk/vm/keeper.go), which a reader cannot raise, so a render
27// that exceeds it makes the page permanently unreadable. Measured with
28// `gno test -v` on gno master.184 (2026-09-17):
29//
30//	diff of a 33 KB body against itself plus one line    691M gas   23% of the ceiling
31//	article render of a 33 KB body with links            693M gas   23% of the ceiling
32//
33// gno test reports gas per test function but a test cannot assert on it, so
34// this test pins the shape, not the number: it fails if either path starts
35// panicking or truncating at the limit. Re-measure with `gno test -v` and
36// update the table when either path changes.
37func TestWorstCaseRendersStayWithinTheQueryBudget(t *testing.T) {
38	w := New(3, DefaultMaxBody)
39	body := buildLines(maxLines-2) + "see [[Other page]]\n[[Category:Big]]\n"
40	uassert.True(t, len(body) < DefaultMaxBody, "the fixture must fit in MaxBody")
41
42	now, h := at(1)
43	_, err := w.Edit(alice, now, h, "Big", body, "", false)
44	uassert.NoError(t, err)
45
46	p, err := w.Page("Big")
47	uassert.NoError(t, err)
48
49	c := Ctx{Base: "/r/moul/x/wiki/v0", Exists: w.Exists}
50	uassert.True(t, len(RenderArticle(c, w, p, nil)) > len(body), "the article must render in full")
51
52	now, h = at(2)
53	_, err = w.Edit(alice, now, h, "Big", body+"added\n", "", false)
54	uassert.NoError(t, err)
55
56	hist := p.History(0, 2)
57	out := RenderDiff(c, p, hist[1], hist[0])
58	uassert.True(t, strings.Contains(out, "+1 −0 lines"), "a one-line append to a 32 KiB body diffs exactly")
59}