5c: the build, the freeze audit and the release pipeline

src/result.test.ts

@@ -0,0 +1,31 @@
+import assert from 'node:assert/strict'
+import { readFileSync, readdirSync } from 'node:fs'
+import { dirname, join } from 'node:path'
+import test from 'node:test'
+import { fileURLToPath } from 'node:url'
+
+const sourceRoot = dirname(fileURLToPath(import.meta.url))
+const union = /export type ConvertErrorCode =\n((?:\s+\| '[a-z-]+'\n)+)/
+const declared = /'([a-z-]+)'/g
+const callSite = /(?:failure\(|code: )'([a-z-]+)'/g
+
+function declaredCodes(): string[] {
+  const source = readFileSync(join(sourceRoot, 'result.ts'), 'utf8')
+  const members = union.exec(source)?.[1]
+  assert.notEqual(members, undefined, 'result.ts declares no ConvertErrorCode union')
+  return [...(members ?? '').matchAll(declared)].map(([, name]) => name ?? '').sort()
+}
+
+function calledCodes(): string[] {
+  const called = new Set<string>()
+  for (const name of readdirSync(sourceRoot, { encoding: 'utf8', recursive: true })) {
+    if (!name.endsWith('.ts') || name.endsWith('.test.ts') || name === 'result.ts') continue
+    for (const [, code] of readFileSync(join(sourceRoot, name), 'utf8').matchAll(callSite)) called.add(code ?? '')
+  }
+  return [...called].sort()
+}
+
+// The list is frozen at 0.1.0 (AGENTS.md §8), so a code outliving its cause is a removal that costs a MAJOR.
+test('every ConvertErrorCode is the code of a production call site, and every call site names a declared one', () => {
+  assert.deepEqual(calledCodes(), declaredCodes())
+})