render_test.gno

 1package lru
 2
 3import (
 4	"strconv"
 5	"strings"
 6	"testing"
 7
 8	"gno.land/p/nt/uassert/v0"
 9)
10
11// clear empties the cache without needing a realm argument, so examples (which
12// take no `cur`) can start from a known state. Examples run after all tests.
13func clear() {
14	c = &cache{index: make(map[string]*node)}
15}
16
17// ExampleRender pins the empty-cache view.
18func ExampleRender() {
19	clear()
20	print(Render(""))
21	// Output:
22	// # LRU Cache
23	//
24	// A fixed-capacity least-recently-used cache.
25	//
26	// ## Stats
27	//
28	// - Capacity: 8
29	// - Size: 0
30	// - Hits: 0
31	// - Misses: 0
32	// - Hit rate: n/a
33	//
34	// ## Entries (MRU → LRU)
35	//
36	// _empty_
37}
38
39// TestRenderListsEntriesMRUFirst checks the table is ordered most-recently-used
40// first and renumbered from 1.
41func TestRenderListsEntriesMRUFirst(cur realm, t *testing.T) {
42	reset(cur)
43	Put(cross(cur), "a", "1")
44	Put(cross(cur), "b", "2")
45	Put(cross(cur), "c", "3")
46	Get(cross(cur), "a") // a becomes MRU
47
48	out := Render("")
49	uassert.True(t, strings.Contains(out, "| 1 | a | 1 |\n| 2 | c | 3 |\n| 3 | b | 2 |\n"),
50		"entries should be listed MRU->LRU: a, c, b")
51	uassert.True(t, strings.Contains(out, "- Size: 3\n"), "size should be 3")
52}
53
54// TestRenderHitRate covers the integer-percent branch and the n/a branch.
55func TestRenderHitRate(cur realm, t *testing.T) {
56	reset(cur)
57	uassert.True(t, strings.Contains(Render(""), "- Hit rate: n/a\n"),
58		"no lookups yet should render n/a")
59
60	Put(cross(cur), "a", "1")
61	Get(cross(cur), "a")   // hit
62	Get(cross(cur), "nope") // miss
63
64	out := Render("")
65	uassert.True(t, strings.Contains(out, "- Hits: 1\n"), "one hit")
66	uassert.True(t, strings.Contains(out, "- Misses: 1\n"), "one miss")
67	uassert.True(t, strings.Contains(out, "- Hit rate: 50%\n"), "1/2 should be 50%")
68}
69
70// TestRenderCapacityMatchesConst guards the header against a capacity change
71// that the pinned example would otherwise silently disagree with.
72func TestRenderCapacityMatchesConst(cur realm, t *testing.T) {
73	reset(cur)
74	uassert.True(t, strings.Contains(Render(""), "- Capacity: "+strconv.Itoa(capacity)+"\n"),
75		"rendered capacity should match the constant")
76}
77
78// TestRenderIgnoresPath documents that Render has no sub-routes.
79func TestRenderIgnoresPath(cur realm, t *testing.T) {
80	reset(cur)
81	Put(cross(cur), "k", "v")
82	uassert.Equal(t, Render(""), Render("/whatever"))
83}