refactor(chart): enforce 400-line source limit

scripts/check-file-length.mjs

@@ -0,0 +1,45 @@
+import { readdirSync, readFileSync } from 'node:fs'
+import { relative, resolve } from 'node:path'
+import { pathToFileURL } from 'node:url'
+
+export const maximumLines = 400
+
+export function physicalLineCount(contents) {
+  if (contents.length === 0) return 0
+  return contents.split('\n').length - Number(contents.endsWith('\n'))
+}
+
+export function isTextFile(contents) {
+  return !contents.includes(0)
+}
+
+export function collectTextFiles(directory) {
+  return readdirSync(directory, { withFileTypes: true }).flatMap((entry) => {
+    const path = resolve(directory, entry.name)
+    if (entry.isDirectory()) return collectTextFiles(path)
+    if (!entry.isFile()) return []
+    const contents = readFileSync(path)
+    return isTextFile(contents) ? [{ path, contents: contents.toString('utf8') }] : []
+  })
+}
+
+export function findFileLengthViolations(sourceRoot, limit = maximumLines) {
+  return collectTextFiles(sourceRoot).flatMap(({ path, contents }) => {
+    const lineCount = physicalLineCount(contents)
+    if (lineCount <= limit) return []
+    return [{ path: relative(process.cwd(), path), lineCount, limit }]
+  })
+}
+
+function run() {
+  const violations = findFileLengthViolations(resolve('src'))
+  if (!violations.length) return
+  console.error('Files exceed the source file length limit:')
+  violations.forEach(({ path, lineCount, limit }) => {
+    console.error(`  ${path}: ${lineCount} lines (maximum ${limit})`)
+  })
+  process.exitCode = 1
+}
+
+const entryPath = process.argv[1] ? pathToFileURL(resolve(process.argv[1])).href : ''
+if (import.meta.url === entryPath) run()