| 1 | package fonts_test |
| 2 | |
| 3 | import ( |
| 4 | "strings" |
| 5 | "testing" |
| 6 | |
| 7 | "github.com/carlosframework/docs/internal/fonts" |
| 8 | ) |
| 9 | |
| 10 | func TestEveryFaceParses(t *testing.T) { |
| 11 | all := fonts.All() |
| 12 | if len(all) != 12 { |
| 13 | t.Fatalf("want 12 faces (3 families x 4 styles), got %d", len(all)) |
| 14 | } |
| 15 | for _, face := range all { |
| 16 | font, err := face.Parsed() |
| 17 | if err != nil { |
| 18 | t.Fatalf("%s: %v", face.File, err) |
| 19 | } |
| 20 | if font.UnitsPerEm == 0 || font.NumGlyphs == 0 { |
| 21 | t.Errorf("%s: unitsPerEm=%d numGlyphs=%d", face.File, font.UnitsPerEm, font.NumGlyphs) |
| 22 | } |
| 23 | if font.Ascender <= 0 || font.Descender >= 0 { |
| 24 | t.Errorf("%s: implausible vertical metrics asc=%d desc=%d", face.File, font.Ascender, font.Descender) |
| 25 | } |
| 26 | // Every face must be able to set ordinary prose. A face whose |
| 27 | // cmap this build failed to read still parses, so the check |
| 28 | // that matters is that letters resolve to real glyphs. |
| 29 | for _, r := range "The quick brown fox, 0123456789 — “quoted” café" { |
| 30 | if font.GlyphIndex(r) == 0 { |
| 31 | t.Errorf("%s: no glyph for %q", face.File, r) |
| 32 | } |
| 33 | } |
| 34 | } |
| 35 | } |
| 36 | |
| 37 | // Advance widths are what every measurement in internal/pdf is built |
| 38 | // on. A monospace face is the one where a wrong answer is unmissable: |
| 39 | // every glyph must advance by the same amount. |
| 40 | func TestMonoAdvancesAreUniform(t *testing.T) { |
| 41 | font, err := fonts.Get(fonts.Mono, false, false).Parsed() |
| 42 | if err != nil { |
| 43 | t.Fatal(err) |
| 44 | } |
| 45 | want := font.Advance(font.GlyphIndex('m')) |
| 46 | if want == 0 { |
| 47 | t.Fatal("no advance for 'm'") |
| 48 | } |
| 49 | for _, r := range "il.MW@" { |
| 50 | if got := font.Advance(font.GlyphIndex(r)); got != want { |
| 51 | t.Errorf("mono advance for %q = %d, want %d", r, got, want) |
| 52 | } |
| 53 | } |
| 54 | } |
| 55 | |
| 56 | // The proportional faces must NOT be uniform — the same assertion the |
| 57 | // other way round, so a bug that returned one constant width for |
| 58 | // everything cannot pass both tests. |
| 59 | func TestProportionalAdvancesDiffer(t *testing.T) { |
| 60 | font, err := fonts.Get(fonts.Serif, false, false).Parsed() |
| 61 | if err != nil { |
| 62 | t.Fatal(err) |
| 63 | } |
| 64 | narrow := font.Advance(font.GlyphIndex('i')) |
| 65 | wide := font.Advance(font.GlyphIndex('W')) |
| 66 | if narrow == 0 || wide == 0 || narrow >= wide { |
| 67 | t.Errorf("serif advances: i=%d W=%d, want 0 < i < W", narrow, wide) |
| 68 | } |
| 69 | } |
| 70 | |
| 71 | func TestWidthEmScalesWithTheString(t *testing.T) { |
| 72 | font, err := fonts.Get(fonts.Serif, false, false).Parsed() |
| 73 | if err != nil { |
| 74 | t.Fatal(err) |
| 75 | } |
| 76 | one, gids := font.WidthEm("n") |
| 77 | two, _ := font.WidthEm("nn") |
| 78 | if len(gids) != 1 { |
| 79 | t.Errorf("WidthEm returned %d gids for one rune", len(gids)) |
| 80 | } |
| 81 | if one <= 0 { |
| 82 | t.Fatalf("width of %q is %v", "n", one) |
| 83 | } |
| 84 | if diff := two - 2*one; diff > 1e-9 || diff < -1e-9 { |
| 85 | t.Errorf("width(nn)=%v, want 2*width(n)=%v", two, 2*one) |
| 86 | } |
| 87 | } |
| 88 | |
| 89 | // The subset has to be a font a reader can actually use, so this |
| 90 | // parses the output rather than checking that it got smaller. Glyph |
| 91 | // ids must survive unchanged (the whole design — see truetype.go), the |
| 92 | // kept glyphs must still have outlines, and a dropped glyph must be |
| 93 | // empty rather than missing. |
| 94 | func TestSubsetKeepsGlyphIdsAndOutlines(t *testing.T) { |
| 95 | face := fonts.Get(fonts.Serif, false, false) |
| 96 | font, err := face.Parsed() |
| 97 | if err != nil { |
| 98 | t.Fatal(err) |
| 99 | } |
| 100 | |
| 101 | keep := map[uint16]bool{} |
| 102 | const sample = "Hello" |
| 103 | for _, r := range sample { |
| 104 | keep[font.GlyphIndex(r)] = true |
| 105 | } |
| 106 | |
| 107 | sub, err := font.Subset(keep) |
| 108 | if err != nil { |
| 109 | t.Fatal(err) |
| 110 | } |
| 111 | if len(sub) >= len(face.Data) { |
| 112 | t.Errorf("subset is %d bytes, original is %d — not a subset", len(sub), len(face.Data)) |
| 113 | } |
| 114 | |
| 115 | reparsed, err := fonts.Parse(sub) |
| 116 | if err != nil { |
| 117 | t.Fatalf("the subset does not parse: %v", err) |
| 118 | } |
| 119 | if reparsed.NumGlyphs != font.NumGlyphs { |
| 120 | t.Errorf("subset numGlyphs=%d, want %d unchanged", reparsed.NumGlyphs, font.NumGlyphs) |
| 121 | } |
| 122 | if reparsed.UnitsPerEm != font.UnitsPerEm { |
| 123 | t.Errorf("subset unitsPerEm=%d, want %d", reparsed.UnitsPerEm, font.UnitsPerEm) |
| 124 | } |
| 125 | for _, r := range sample { |
| 126 | gid := font.GlyphIndex(r) |
| 127 | if got := reparsed.Advance(gid); got != font.Advance(gid) { |
| 128 | t.Errorf("advance for %q changed: %d -> %d", r, font.Advance(gid), got) |
| 129 | } |
| 130 | if !glyphHasOutline(t, sub, gid) { |
| 131 | t.Errorf("kept glyph for %q has no outline in the subset", r) |
| 132 | } |
| 133 | } |
| 134 | |
| 135 | // A glyph nobody asked for must be gone. 'Z' is not in "Hello". |
| 136 | if gid := font.GlyphIndex('Z'); gid != 0 && glyphHasOutline(t, sub, gid) { |
| 137 | t.Errorf("glyph for 'Z' survived a subset that did not ask for it") |
| 138 | } |
| 139 | } |
| 140 | |
| 141 | // The hinting tables travel with the glyphs. ISO 32000-1 §9.9 requires |
| 142 | // cvt /fpgm/prep to be in an embedded font whose instructions need |
| 143 | // them, and Liberation's glyph programs call functions defined in fpgm |
| 144 | // and read values from cvt — so a subset without them is executing |
| 145 | // instructions against definitions that are not in the file. |
| 146 | func TestSubsetKeepsTheHintingTables(t *testing.T) { |
| 147 | face := fonts.Get(fonts.Serif, false, false) |
| 148 | font, err := face.Parsed() |
| 149 | if err != nil { |
| 150 | t.Fatal(err) |
| 151 | } |
| 152 | sub, err := font.Subset(map[uint16]bool{font.GlyphIndex('A'): true}) |
| 153 | if err != nil { |
| 154 | t.Fatal(err) |
| 155 | } |
| 156 | for _, tag := range []string{"cvt ", "fpgm", "prep"} { |
| 157 | if !fontHasTable(t, sub, tag) { |
| 158 | t.Errorf("the subset dropped %q, which its glyph instructions need", tag) |
| 159 | } |
| 160 | } |
| 161 | // And it is still a subset: the hinting tables are tens of |
| 162 | // kilobytes, not hundreds. |
| 163 | if len(sub) >= len(face.Data)/2 { |
| 164 | t.Errorf("subset is %d bytes against a %d-byte face — the hinting tables should not cost that much", |
| 165 | len(sub), len(face.Data)) |
| 166 | } |
| 167 | } |
| 168 | |
| 169 | // fontHasTable reports whether a built font file carries a table. |
| 170 | func fontHasTable(t *testing.T, file []byte, tag string) bool { |
| 171 | t.Helper() |
| 172 | if len(file) < 12 { |
| 173 | t.Fatal("not a font") |
| 174 | } |
| 175 | n := int(file[4])<<8 | int(file[5]) |
| 176 | for i := 0; i < n; i++ { |
| 177 | rec := 12 + i*16 |
| 178 | if rec+4 > len(file) { |
| 179 | break |
| 180 | } |
| 181 | if string(file[rec:rec+4]) == tag { |
| 182 | return true |
| 183 | } |
| 184 | } |
| 185 | return false |
| 186 | } |
| 187 | |
| 188 | // A composite glyph's components must come along, or the accent |
| 189 | // renders as nothing. |
| 190 | func TestSubsetFollowsCompositeComponents(t *testing.T) { |
| 191 | face := fonts.Get(fonts.Serif, false, false) |
| 192 | font, err := face.Parsed() |
| 193 | if err != nil { |
| 194 | t.Fatal(err) |
| 195 | } |
| 196 | gid := font.GlyphIndex('é') |
| 197 | if gid == 0 { |
| 198 | t.Skip("no é in this face") |
| 199 | } |
| 200 | sub, err := font.Subset(map[uint16]bool{gid: true}) |
| 201 | if err != nil { |
| 202 | t.Fatal(err) |
| 203 | } |
| 204 | if !glyphHasOutline(t, sub, gid) { |
| 205 | t.Fatal("é itself is missing from its own subset") |
| 206 | } |
| 207 | // 'e' was never asked for; it must still be present, because é is |
| 208 | // assembled from it. (If this face happens to draw é as a simple |
| 209 | // glyph, the assertion still holds trivially — é has an outline |
| 210 | // either way — so this cannot pass by accident on a face where |
| 211 | // there is nothing to follow.) |
| 212 | base := font.GlyphIndex('e') |
| 213 | if isComposite(t, face.Data, font, gid) && !glyphHasOutline(t, sub, base) { |
| 214 | t.Error("é is composite but its base glyph was dropped from the subset") |
| 215 | } |
| 216 | } |
| 217 | |
| 218 | // glyphHasOutline reports whether gid occupies bytes in the file's |
| 219 | // glyf table — the actual question a reader asks when it draws. |
| 220 | func glyphHasOutline(t *testing.T, file []byte, gid uint16) bool { |
| 221 | t.Helper() |
| 222 | f, err := fonts.Parse(file) |
| 223 | if err != nil { |
| 224 | t.Fatalf("parse: %v", err) |
| 225 | } |
| 226 | return f.GlyphLen(gid) > 0 |
| 227 | } |
| 228 | |
| 229 | func isComposite(t *testing.T, file []byte, orig *fonts.Font, gid uint16) bool { |
| 230 | t.Helper() |
| 231 | f, err := fonts.Parse(file) |
| 232 | if err != nil { |
| 233 | t.Fatalf("parse: %v", err) |
| 234 | } |
| 235 | return f.GlyphIsComposite(gid) |
| 236 | } |
| 237 | |
| 238 | // Every face is served at a content-hashed path, so the URL changes |
| 239 | // whenever the bytes do and the year-long cache header is safe. |
| 240 | func TestFacePathsAreUniqueAndHashed(t *testing.T) { |
| 241 | seen := map[string]bool{} |
| 242 | for _, f := range fonts.All() { |
| 243 | if !strings.HasPrefix(f.Path, fonts.PathPrefix) || !strings.HasSuffix(f.Path, ".ttf") { |
| 244 | t.Errorf("%s: unexpected path %q", f.File, f.Path) |
| 245 | } |
| 246 | if seen[f.Path] { |
| 247 | t.Errorf("duplicate path %q", f.Path) |
| 248 | } |
| 249 | seen[f.Path] = true |
| 250 | got, ok := fonts.Asset(f.Path) |
| 251 | if !ok || got.File != f.File { |
| 252 | t.Errorf("Asset(%q) did not round-trip to %s", f.Path, f.File) |
| 253 | } |
| 254 | } |
| 255 | } |
| 256 | |
| 257 | func TestLicenceTravelsWithTheFonts(t *testing.T) { |
| 258 | l := fonts.Licence() |
| 259 | if !strings.Contains(l, "SIL OPEN FONT LICENSE Version 1.1") { |
| 260 | t.Error("the OFL text is not what is being served") |
| 261 | } |
| 262 | if strings.Contains(l, "GNU General Public License") { |
| 263 | t.Error("the Debian packaging licence leaked into the font licence file") |
| 264 | } |
| 265 | } |
| 266 | |
| 267 | func TestFamilyKeysRoundTrip(t *testing.T) { |
| 268 | for _, fam := range []fonts.Family{fonts.Serif, fonts.Sans, fonts.Mono} { |
| 269 | got, ok := fonts.FamilyForKey(fam.Key()) |
| 270 | if !ok || got != fam { |
| 271 | t.Errorf("%q did not round-trip", fam.Key()) |
| 272 | } |
| 273 | } |
| 274 | if _, ok := fonts.FamilyForKey("comic"); ok { |
| 275 | t.Error("an unknown family key must be a miss, not a silent serif") |
| 276 | } |
| 277 | } |
| 278 | |
amadan