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fix(scripts): stop the frontmatter field regex backtracking quadratically #1206

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Merged
BryanFRD merged 1 commit into from
Sep 27, 2026
Merged

fix(scripts): stop the frontmatter field regex backtracking quadratically #1206

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4 changes: 2 additions & 2 deletions scripts/validate-site-docs.mjs
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Original file line number Diff line number Diff line change
Expand Up @@ -6,7 +6,7 @@ const root = fileURLToPath(new URL('..', import.meta.url));
const contentDir = join(root, 'docs/site');

const FRONTMATTER = /^---\r?\n([\s\S]*?)\r?\n---\r?\n/;
const FIELD = /^([A-Za-z_][A-Za-z0-9_]*):\s*(.*?)\s*$/;
const FIELD = /^([A-Za-z_]\w*):(.*)$/;

@ferrfleet ferrfleet Bot Sep 27, 2026

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Nit: (.*)$ is not quite equivalent to the old \s*(.*?)\s*$, because . excludes \r, 
 and 
 while \s includes the first two. On a line ending in one of those (title:a\r), the old pattern matched and stored a; the new one cannot match at all, so the field silently disappears and validation reports a missing title.

Not reachable through the current call path, as far as I can tell: the block is split on /\r?\n/, and a CR-only file never matches FRONTMATTER in the first place, so it takes something like a doubled \r\r\n to get there. Still, [\s\S] costs nothing and is just as linear (greedy, runs straight to the end, $ matches in one step):

Suggested change
const FIELD = /^([A-Za-z_]\w*):(.*)$/;
const FIELD = /^([A-Za-z_]\w*):([\s\S]*)$/;


function walk(dir) {
return readdirSync(dir).flatMap((name) => {
Expand All @@ -24,7 +24,7 @@ function frontmatter(raw) {
for (const line of block[1].split(/\r?\n/)) {
const field = FIELD.exec(line);
if (field) {
fields.set(field[1], field[2].replace(/^['"]|['"]$/g, ''));
fields.set(field[1], field[2].trim().replace(/^['"]|['"]$/g, ''));
}
}
return fields;
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