| 1 | package slidestest |
| 2 | |
| 3 | import ( |
| 4 | "crypto/sha256" |
| 5 | "encoding/hex" |
| 6 | "fmt" |
| 7 | "net/http" |
| 8 | "os" |
| 9 | "path/filepath" |
| 10 | "regexp" |
| 11 | "strings" |
| 12 | "testing" |
| 13 | |
| 14 | "amadan.net/oficina/slides/internal/slides/fonts" |
| 15 | ) |
| 16 | |
| 17 | // This file holds slides.css's half of "one font set everywhere" to |
| 18 | // the Go half. The stylesheet is a static file — nothing templates it |
| 19 | // — so the twelve @font-face URLs, the fallback stacks and the served |
| 20 | // bytes are all things that can drift silently. These tests are what |
| 21 | // notice. |
| 22 | |
| 23 | func slidesCSS(t *testing.T) string { |
| 24 | t.Helper() |
| 25 | b, err := os.ReadFile(filepath.Join("..", "slides", "static", "slides.css")) |
| 26 | if err != nil { |
| 27 | t.Fatalf("read slides.css: %v", err) |
| 28 | } |
| 29 | return string(b) |
| 30 | } |
| 31 | |
| 32 | // fontFaceSrc pulls each @font-face's family, style, weight and URL |
| 33 | // out in the order slides.css writes them. |
| 34 | var fontFaceRule = regexp.MustCompile(`(?s)@font-face \{(.*?)\}`) |
| 35 | |
| 36 | type faceRule struct { |
| 37 | family, style, weight, url string |
| 38 | } |
| 39 | |
| 40 | func parseFontFaces(t *testing.T, css string) []faceRule { |
| 41 | t.Helper() |
| 42 | field := func(body, name string) string { |
| 43 | re := regexp.MustCompile(name + `:\s*([^;]+);`) |
| 44 | m := re.FindStringSubmatch(body) |
| 45 | if m == nil { |
| 46 | return "" |
| 47 | } |
| 48 | return strings.Trim(strings.TrimSpace(m[1]), `"`) |
| 49 | } |
| 50 | var out []faceRule |
| 51 | for _, m := range fontFaceRule.FindAllStringSubmatch(css, -1) { |
| 52 | body := m[1] |
| 53 | src := field(body, "src") |
| 54 | u := regexp.MustCompile(`url\("([^"]+)"\)`).FindStringSubmatch(src) |
| 55 | if u == nil { |
| 56 | t.Errorf("an @font-face has no url(): %q", src) |
| 57 | continue |
| 58 | } |
| 59 | out = append(out, faceRule{ |
| 60 | family: field(body, "font-family"), |
| 61 | style: field(body, "font-style"), |
| 62 | weight: field(body, "font-weight"), |
| 63 | url: u[1], |
| 64 | }) |
| 65 | } |
| 66 | return out |
| 67 | } |
| 68 | |
| 69 | // Every one of the twelve embedded faces is declared, once, under its |
| 70 | // own family name and with the weight and slope that select it. A face |
| 71 | // the engine measures with and the browser cannot fetch is the |
| 72 | // divergence this whole font set exists to close. |
| 73 | func TestSlidesCSSDeclaresEveryEmbeddedFace(t *testing.T) { |
| 74 | rules := parseFontFaces(t, slidesCSS(t)) |
| 75 | got := map[string]string{} |
| 76 | for _, r := range rules { |
| 77 | key := fmt.Sprintf("%s|%s|%s", r.family, r.style, r.weight) |
| 78 | if prev, dup := got[key]; dup { |
| 79 | t.Errorf("%s is declared twice (%s and %s)", key, prev, r.url) |
| 80 | } |
| 81 | got[key] = r.url |
| 82 | } |
| 83 | for _, f := range fonts.All() { |
| 84 | style, weight := "normal", "400" |
| 85 | if f.Italic { |
| 86 | style = "italic" |
| 87 | } |
| 88 | if f.Bold { |
| 89 | weight = "700" |
| 90 | } |
| 91 | key := fmt.Sprintf("%s|%s|%s", f.Family.CSSName(), style, weight) |
| 92 | url, ok := got[key] |
| 93 | if !ok { |
| 94 | t.Errorf("slides.css declares no @font-face for %s (%s)", f.File(), key) |
| 95 | continue |
| 96 | } |
| 97 | if !strings.HasPrefix(url, "fonts/"+strings.TrimSuffix(f.File(), ".ttf")+".") { |
| 98 | t.Errorf("%s is declared as %q, which is not that face's file", key, url) |
| 99 | } |
| 100 | delete(got, key) |
| 101 | } |
| 102 | for key, url := range got { |
| 103 | t.Errorf("slides.css declares %s (%s), which is not a face this build embeds", key, url) |
| 104 | } |
| 105 | } |
| 106 | |
| 107 | // The URLs carry a content hash so rastrillo's asset handler serves |
| 108 | // them immutable rather than no-cache — a slide is a page load, and |
| 109 | // refetching a megabyte of fonts on every next-slide link is not a |
| 110 | // cost worth paying for a set of files that never change. |
| 111 | // |
| 112 | // A stale hash is not a broken page (the handler strips it, finds the |
| 113 | // file and serves it no-cache), so this failing means "slower", not |
| 114 | // "broken" — the message says what to write instead. |
| 115 | func TestSlidesCSSFontURLsCarryTheirContentHash(t *testing.T) { |
| 116 | for _, r := range parseFontFaces(t, slidesCSS(t)) { |
| 117 | name := strings.TrimPrefix(r.url, "fonts/") |
| 118 | parts := strings.Split(name, ".") |
| 119 | if len(parts) != 3 || parts[2] != "ttf" || len(parts[1]) != 16 { |
| 120 | t.Errorf("%q is not <face>.<16 hex>.ttf", r.url) |
| 121 | continue |
| 122 | } |
| 123 | b, err := os.ReadFile(filepath.Join("..", "slides", "static", "fonts", parts[0]+".ttf")) |
| 124 | if err != nil { |
| 125 | t.Errorf("%s: %v", r.url, err) |
| 126 | continue |
| 127 | } |
| 128 | sum := sha256.Sum256(b) |
| 129 | if want := hex.EncodeToString(sum[:])[:16]; parts[1] != want { |
| 130 | t.Errorf("%s carries a stale hash; write fonts/%s.%s.ttf", r.url, parts[0], want) |
| 131 | } |
| 132 | } |
| 133 | } |
| 134 | |
| 135 | // The stylesheet's own fallback stacks — what a section that arrived |
| 136 | // without inline custom properties renders as — name the same faces |
| 137 | // the themes do. |
| 138 | func TestSlidesCSSFallbackStacksAreTheEmbeddedFamilies(t *testing.T) { |
| 139 | css := slidesCSS(t) |
| 140 | for _, c := range []struct { |
| 141 | prop string |
| 142 | fam fonts.Family |
| 143 | }{ |
| 144 | {"--slides-font-heading", fonts.Serif}, |
| 145 | {"--slides-font-body", fonts.Sans}, |
| 146 | {"--slides-font-code", fonts.Mono}, |
| 147 | } { |
| 148 | want := c.prop + ": " + c.fam.Stack() + ";" |
| 149 | if !strings.Contains(css, want) { |
| 150 | t.Errorf("slides.css does not set %q", want) |
| 151 | } |
| 152 | } |
| 153 | } |
| 154 | |
| 155 | // The end of the wire: the app serves the bytes at the URL the |
| 156 | // stylesheet asks for, with the immutable Cache-Control the hash buys. |
| 157 | func TestTheAppServesTheDeclaredFontFiles(t *testing.T) { |
| 158 | a := newApp(t) |
| 159 | for _, r := range parseFontFaces(t, slidesCSS(t)) { |
| 160 | rec := get(t, a, "/static/"+r.url) |
| 161 | if rec.Code != http.StatusOK { |
| 162 | t.Errorf("GET /static/%s: %d", r.url, rec.Code) |
| 163 | continue |
| 164 | } |
| 165 | if got := rec.Header().Get("Cache-Control"); !strings.Contains(got, "immutable") { |
| 166 | t.Errorf("GET /static/%s: Cache-Control %q, want an immutable one", r.url, got) |
| 167 | } |
| 168 | if rec.Body.Len() < 100_000 { |
| 169 | t.Errorf("GET /static/%s returned %d bytes", r.url, rec.Body.Len()) |
| 170 | } |
| 171 | } |
| 172 | } |
| 173 | |
| 174 | // The licence travels with the fonts, as the OFL requires of anything |
| 175 | // redistributing them — and a slide surface is redistribution. |
| 176 | func TestTheAppServesTheFontLicence(t *testing.T) { |
| 177 | a := newApp(t) |
| 178 | rec := get(t, a, "/static/fonts/LICENSE-OFL-1.1.txt") |
| 179 | if rec.Code != http.StatusOK { |
| 180 | t.Fatalf("GET the font licence: %d", rec.Code) |
| 181 | } |
| 182 | if !strings.Contains(rec.Body.String(), "SIL OPEN FONT LICENSE") { |
| 183 | t.Error("the served licence is not the OFL") |
| 184 | } |
| 185 | } |
| 186 | |
amadan