fix(#1391): boot-time ValidationPipe metatype self-check — fail loud at startup (#1419)

Co-authored-by: code-infra-01 <[email protected]>
2026-08-25 14:01:24 +00:00
parent d30a4cce00
commit b2d40dada0
3 changed files with 204 additions and 0 deletions
@@ -0,0 +1,94 @@
+import 'reflect-metadata';
+import { getMetadataStorage } from 'class-validator';
+import { BootstrapSetupDto } from './admin/bootstrap.dto.js';
+
+/**
+ * Boot-time self-check: the global ValidationPipe must be able to SEE the
+ * decorated properties of the DTOs it guards (#1391, #436 class).
+ *
+ * WHY THIS EXISTS. When Nest resolves a @Body() metatype to Object — via
+ * `import type` class erasure (#436), or a dependency graph where the
+ * controller's decorators and the application's route enhancers disagree
+ * (#1391's hypothesized dual-@nestjs/common on a mixed install) — the
+ * ValidationPipe's whitelist treats every property as forbidden. The first
+ * symptom is a 400 on the FIRST bootstrap attempt of a fresh install, the
+ * worst place to discover wiring damage: the operator cannot tell a broken
+ * payload from a broken daemon.
+ *
+ * This check fails LOUD at boot instead: if the pipe cannot see the DTO's
+ * decorated properties, the gateway refuses to start with a named cause.
+ * It catches the whole class — erasure, decorator metadata loss — on every
+ * host, at the moment the damage exists rather than at first use.
+ *
+ * Storage sharing note: class-validator keys its metadata storage on
+ * globalThis, so duplicate package copies do NOT hide metadata (measured,
+ * #1391 diagnosis). What hides it is losing the metatype itself, which is
+ * what this asserts against.
+ */
+
+/**
+ * DTOs the global pipe guards, mapped to the properties the whitelist must
+ * admit. Target is the CONSTRUCTOR (the object class itself): class-validator
+ * decorators register metadata keyed on the constructor, and its executor
+ * looks up `object.constructor` (ValidationExecutor.js:50) — the probe
+ * through `prototype` returns zero. Extend when adding DTOs to the app.
+ */
+export const PIPE_GUARDED_DTOS: Array<{
+  name: string;
+  target: abstract new (...args: never[]) => unknown;
+  properties: string[];
+}> = [
+  {
+    name: 'BootstrapSetupDto',
+    target: BootstrapSetupDto,
+    properties: ['name', 'email', 'password'],
+  },
+];
+
+export class PipeMetatypeCheckError extends Error {
+  constructor(missing: string[]) {
+    super(
+      'ValidationPipe metatype check failed: ' +
+        missing.join('; ') +
+        '. The global ValidationPipe cannot see decorated DTO properties — ' +
+        'every request body would be rejected as non-whitelisted. ' +
+        'Check for import-type erasure or decorator metadata loss in the ' +
+        'dependency graph (see issues #436, #1391).',
+    );
+    this.name = 'PipeMetatypeCheckError';
+  }
+}
+
+/**
+ * Assert the pipe's whitelist can see every guarded DTO's decorated
+ * properties. Throws PipeMetatypeCheckError (fail-loud at boot) listing
+ * each miss. Pure function of module state: no I/O, safe to call twice.
+ */
+export function assertValidationPipeSeesDtoDecorators(): void {
+  const storage = getMetadataStorage();
+  const missing: string[] = [];
+
+  for (const dto of PIPE_GUARDED_DTOS) {
+    // class-validator records constraints keyed on the DTO's constructor
+    // (decorators run on the class), and its executor resolves them via
+    // object.constructor. A property with no recorded metadata is invisible
+    // to the whitelist — whatever the cause — and fails here.
+    // Signature mirrors ValidationExecutor.js:50 — (constructor, schema, always,
+    // strictGroups, groups?). No schema, always=true, no groups: every
+    // constraint regardless of grouping, which is what the whitelist sees.
+    const metadatas = storage.getTargetValidationMetadatas(dto.target, '', true, false);
+    const decorated = new Set(metadatas.map((m) => m.propertyName));
+
+    for (const property of dto.properties) {
+      if (!decorated.has(property)) {
+        missing.push(
+          `${dto.name}.${property} has no class-validator constraints visible to the pipe`,
+        );
+      }
+    }
+  }
+
+  if (missing.length > 0) {
+    throw new PipeMetatypeCheckError(missing);
+  }
+}