feat: add the dsh-superagent research prototype

tests/class-docs.spec.ts

@@ -0,0 +1,19 @@
+/** Verifies that every class in src has a preceding JSDoc block. */
+import { readdirSync, readFileSync } from 'node:fs'
+import { dirname, join } from 'node:path'
+import { fileURLToPath } from 'node:url'
+import { expect, it } from 'vitest'
+
+const SRC = join(dirname(fileURLToPath(import.meta.url)), '..', 'src')
+
+it('gives every class declaration in src a JSDoc block right before it', () => {
+  const undocumented = readdirSync(SRC, { recursive: true, encoding: 'utf8' }).filter(path => /\.tsx?$/.test(path)).flatMap(path => {
+    const text = readFileSync(join(SRC, path), 'utf8')
+    return [...text.matchAll(/^[ \t]*(?:export\s+)?(?:default\s+)?(?:abstract\s+)?class\s+(\w+)/gm)].flatMap(match => {
+      const before = text.slice(0, match.index).trimEnd()
+      const start = before.lastIndexOf('/**')
+      return start >= 0 && before.indexOf('*/', start) === before.length - 2 ? [] : [`src/${path}: ${match[1]}`]
+    })
+  })
+  expect(undocumented).toEqual([])
+})