| 1 | import fs from "node:fs"; |
| 2 | import path from "node:path"; |
| 3 | import { fileURLToPath, pathToFileURL } from "node:url"; |
| 4 | |
| 5 | const scriptDir = path.dirname(fileURLToPath(import.meta.url)); |
| 6 | const frontendRoot = path.resolve(scriptDir, ".."); |
| 7 | |
| 8 | /** Returns one message per fault site; an empty array means the file is clean. */ |
| 9 | export function checkCssFile(fullPath, label) { |
| 10 | const source = fs.readFileSync(fullPath, "utf8"); |
| 11 | const result = checkCssDelimiters(source); |
| 12 | if (!result.ok) return [`${label}:${result.line}:${result.column}\n${result.message}`]; |
| 13 | |
| 14 | return findGluedPreludes(source).map( |
| 15 | (site) => |
| 16 | `${label}:${site.line}:${site.column}\n` + |
| 17 | ` A selector list runs into the next rule without its own declaration block: "${site.text}"`, |
| 18 | ); |
| 19 | } |
| 20 | |
| 21 | function main(targets) { |
| 22 | const files = targets.length > 0 ? targets : ["src/styles.css"]; |
| 23 | let failed = false; |
| 24 | |
| 25 | for (const file of files) { |
| 26 | const failures = checkCssFile(path.resolve(frontendRoot, file), file); |
| 27 | if (failures.length === 0) { |
| 28 | console.log(`CSS syntax check passed: ${file}`); |
| 29 | continue; |
| 30 | } |
| 31 | failed = true; |
| 32 | for (const failure of failures) console.error(`CSS syntax check failed: ${failure}`); |
| 33 | console.error( |
| 34 | "The CSS parser drops the orphaned selectors and swallows the block that follows, so the\n" + |
| 35 | "damage is invisible in the browser. Restore the deleted block or remove the selectors.", |
| 36 | ); |
| 37 | } |
| 38 | |
| 39 | return failed ? 1 : 0; |
| 40 | } |
| 41 | |
| 42 | if (process.argv[1] && import.meta.url === pathToFileURL(path.resolve(process.argv[1])).href) { |
| 43 | process.exitCode = main(process.argv.slice(2)); |
| 44 | } |
| 45 | |
| 46 | /** |
| 47 | * Finds a selector list that lost its declaration block and ran into the next |
| 48 | * rule. Delimiters stay balanced in that shape, so checkCssDelimiters passes, |
| 49 | * but the CSS parser drops the orphaned selectors and swallows the block that |
| 50 | * follows — a rule silently stops applying. Only multi-line preludes are |
| 51 | * judged: a selector list puts `,` at every line end but the last, so a line |
| 52 | * that breaks that pattern is glued text rather than a selector. |
| 53 | * |
| 54 | * A single-line prelude cannot be judged (`@media (max-width: 820px)` and |
| 55 | * `.a {` look alike), and a glued rule whose last orphan happened to end in |
| 56 | * `,` is textually a legal selector list. Neither is detectable statically; |
| 57 | * both need the rendered-DOM check. |
| 58 | */ |
| 59 | function findGluedPreludes(source) { |
| 60 | const found = []; |
| 61 | let state = "normal"; |
| 62 | let line = 1; |
| 63 | let column = 0; |
| 64 | let buffer = ""; |
| 65 | let bufferLine = 1; |
| 66 | let bufferColumn = 1; |
| 67 | |
| 68 | const judge = () => { |
| 69 | const lines = buffer.split("\n").map((entry) => entry.trim()).filter(Boolean); |
| 70 | if (lines.length < 2) return null; |
| 71 | // A declaration whose value wraps across lines (`--x: linear-gradient(`) |
| 72 | // is not a prelude. Element selectors with a pseudo-class read the same |
| 73 | // way, so they pass unchecked — their siblings still get judged. |
| 74 | if (/^[-*_a-zA-Z][-\w]*\s*:/.test(lines[0])) return null; |
| 75 | for (let i = 0; i < lines.length - 1; i += 1) { |
| 76 | if (!lines[i].endsWith(",")) return lines[i]; |
| 77 | } |
| 78 | return null; |
| 79 | }; |
| 80 | |
| 81 | const reset = (nextLine, nextColumn) => { |
| 82 | buffer = ""; |
| 83 | bufferLine = nextLine; |
| 84 | bufferColumn = nextColumn; |
| 85 | }; |
| 86 | |
| 87 | for (let i = 0; i < source.length; i += 1) { |
| 88 | const char = source[i]; |
| 89 | const next = source[i + 1]; |
| 90 | |
| 91 | if (char === "\n") { |
| 92 | line += 1; |
| 93 | column = 0; |
| 94 | } else { |
| 95 | column += 1; |
| 96 | } |
| 97 | |
| 98 | if (state === "comment") { |
| 99 | if (char === "*" && next === "/") { |
| 100 | i += 1; |
| 101 | column += 1; |
| 102 | state = "normal"; |
| 103 | } |
| 104 | continue; |
| 105 | } |
| 106 | |
| 107 | if (state === "single" || state === "double") { |
| 108 | if (char === "\\") { |
| 109 | i += 1; |
| 110 | column += 1; |
| 111 | continue; |
| 112 | } |
| 113 | if ((state === "single" && char === "'") || (state === "double" && char === '"')) { |
| 114 | state = "normal"; |
| 115 | } |
| 116 | continue; |
| 117 | } |
| 118 | |
| 119 | if (char === "/" && next === "*") { |
| 120 | i += 1; |
| 121 | column += 1; |
| 122 | state = "comment"; |
| 123 | continue; |
| 124 | } |
| 125 | |
| 126 | if (char === "'") { |
| 127 | state = "single"; |
| 128 | continue; |
| 129 | } |
| 130 | |
| 131 | if (char === '"') { |
| 132 | state = "double"; |
| 133 | continue; |
| 134 | } |
| 135 | |
| 136 | if (char === "{" || char === "}") { |
| 137 | const text = judge(); |
| 138 | if (text !== null) found.push({ line: bufferLine, column: bufferColumn, text }); |
| 139 | reset(line, column); |
| 140 | continue; |
| 141 | } |
| 142 | |
| 143 | // A `;` only terminates declarations and at-rules, never a selector list, |
| 144 | // so the buffer it closes is not a prelude worth judging. |
| 145 | if (char === ";") { |
| 146 | reset(line, column); |
| 147 | continue; |
| 148 | } |
| 149 | |
| 150 | // Keep the cursor on the first character that is not whitespace, so the |
| 151 | // reported position names the selector rather than the blank line above it. |
| 152 | if (buffer.trim() === "") { |
| 153 | bufferLine = line; |
| 154 | bufferColumn = column; |
| 155 | } |
| 156 | buffer += char; |
| 157 | } |
| 158 | |
| 159 | const text = judge(); |
| 160 | if (text !== null) found.push({ line: bufferLine, column: bufferColumn, text }); |
| 161 | return found; |
| 162 | } |
| 163 | |
| 164 | function checkCssDelimiters(source) { |
| 165 | const stack = []; |
| 166 | let state = "normal"; |
| 167 | let line = 1; |
| 168 | let column = 0; |
| 169 | let tokenLine = 1; |
| 170 | let tokenColumn = 1; |
| 171 | |
| 172 | for (let i = 0; i < source.length; i += 1) { |
| 173 | const char = source[i]; |
| 174 | const next = source[i + 1]; |
| 175 | |
| 176 | if (char === "\n") { |
| 177 | line += 1; |
| 178 | column = 0; |
| 179 | } else { |
| 180 | column += 1; |
| 181 | } |
| 182 | |
| 183 | if (state === "comment") { |
| 184 | if (char === "*" && next === "/") { |
| 185 | i += 1; |
| 186 | column += 1; |
| 187 | state = "normal"; |
| 188 | } |
| 189 | continue; |
| 190 | } |
| 191 | |
| 192 | if (state === "single" || state === "double") { |
| 193 | if (char === "\\") { |
| 194 | i += 1; |
| 195 | column += 1; |
| 196 | continue; |
| 197 | } |
| 198 | if ((state === "single" && char === "'") || (state === "double" && char === '"')) { |
| 199 | state = "normal"; |
| 200 | } |
| 201 | continue; |
| 202 | } |
| 203 | |
| 204 | if (char === "/" && next === "*") { |
| 205 | tokenLine = line; |
| 206 | tokenColumn = column; |
| 207 | i += 1; |
| 208 | column += 1; |
| 209 | state = "comment"; |
| 210 | continue; |
| 211 | } |
| 212 | |
| 213 | if (char === "'") { |
| 214 | tokenLine = line; |
| 215 | tokenColumn = column; |
| 216 | state = "single"; |
| 217 | continue; |
| 218 | } |
| 219 | |
| 220 | if (char === '"') { |
| 221 | tokenLine = line; |
| 222 | tokenColumn = column; |
| 223 | state = "double"; |
| 224 | continue; |
| 225 | } |
| 226 | |
| 227 | if (char === "{") { |
| 228 | stack.push({ line, column }); |
| 229 | continue; |
| 230 | } |
| 231 | |
| 232 | if (char === "}") { |
| 233 | if (stack.length === 0) { |
| 234 | return { |
| 235 | ok: false, |
| 236 | line, |
| 237 | column, |
| 238 | message: "Found a closing brace without a matching opening brace.", |
| 239 | }; |
| 240 | } |
| 241 | stack.pop(); |
| 242 | } |
| 243 | } |
| 244 | |
| 245 | if (state === "comment") { |
| 246 | return { |
| 247 | ok: false, |
| 248 | line: tokenLine, |
| 249 | column: tokenColumn, |
| 250 | message: "Found an unterminated CSS comment.", |
| 251 | }; |
| 252 | } |
| 253 | |
| 254 | if (state === "single" || state === "double") { |
| 255 | return { |
| 256 | ok: false, |
| 257 | line: tokenLine, |
| 258 | column: tokenColumn, |
| 259 | message: "Found an unterminated CSS string.", |
| 260 | }; |
| 261 | } |
| 262 | |
| 263 | if (stack.length > 0) { |
| 264 | const opener = stack[stack.length - 1]; |
| 265 | return { |
| 266 | ok: false, |
| 267 | line: opener.line, |
| 268 | column: opener.column, |
| 269 | message: "Found an opening brace without a matching closing brace.", |
| 270 | }; |
| 271 | } |
| 272 | |
| 273 | return { ok: true }; |
| 274 | } |
| 275 |