chore(scripts): DB-free view-DDL dumper for projection round-trip checks

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: dmealing

server/typescript/scripts/dump-view-ddl.ts

@@ -0,0 +1,77 @@
+// DB-free view-DDL dumper.
+//
+// Loads a MetaObjects metadata directory, finds projection entities
+// (a read-only `source.rdb @kind:view` with no writable source), and prints
+// the CREATE VIEW DDL each one compiles to — using the same pure functions the
+// CLI's `meta migrate` uses (`extractViewSpec` + `emitViewDdl`). No database.
+//
+// Usage:
+//   bun scripts/dump-view-ddl.ts <metadataDir>              -> all projections
+//   bun scripts/dump-view-ddl.ts <metadataDir> <ViewName>   -> just that one (by entity name OR view name)
+//
+// Mirrors the real call sequence in
+//   packages/cli/src/lib/projection-migrations.ts (computeProjectionMigrations).
+import { MetaDataLoader, resolveTableName } from "@metaobjectsdev/metadata";
+import { isProjection, extractViewSpec, emitViewDdl } from "@metaobjectsdev/codegen-ts";
+
+const dir = process.argv[2];
+const filter = process.argv[3];
+if (!dir) {
+  console.error("need <metadataDir> [ViewNameOrEntityName]");
+  process.exit(2);
+}
+
+const res = await MetaDataLoader.fromDirectory(dir);
+if (res.errors.length) {
+  console.error("LOAD ERRORS:", JSON.stringify(res.errors, null, 2));
+  process.exit(1);
+}
+const root = res.root;
+
+// Resolve table names for every writable entity, exactly as the CLI does, so
+// the emitter can map base entity + joined entities to physical tables.
+const joinTables: Record<string, string> = {};
+for (const obj of root.objects()) {
+  joinTables[obj.name] = resolveTableName(obj);
+}
+
+// Find projection entities (source.rdb @kind:view, read-only, no writable source).
+const projections = root.objects().filter(isProjection);
+
+if (projections.length === 0) {
+  console.error("-- no projection entities found");
+  process.exit(0);
+}
+
+let printed = 0;
+for (const projection of projections) {
+  let spec: ReturnType<typeof extractViewSpec>;
+  let createSql: string;
+  try {
+    spec = extractViewSpec(projection, root, { columnNamingStrategy: "snake_case" });
+    const baseTableName = joinTables[spec.joinTree.baseEntity];
+    if (!baseTableName) {
+      console.log(`-- ${projection.name}: EMIT ERROR: base entity "${spec.joinTree.baseEntity}" has no resolvable table name`);
+      continue;
+    }
+    createSql = emitViewDdl(spec, { dialect: "postgres", baseTableName, joinTables });
+  } catch (e) {
+    console.log(`-- ${projection.name}: EMIT ERROR: ${e instanceof Error ? e.message : String(e)}`);
+    continue;
+  }
+
+  // Filter (after a successful extract so we can match on the physical view name too).
+  if (filter && projection.name !== filter && spec.viewName !== filter) {
+    continue;
+  }
+
+  if (printed > 0) console.log("");
+  console.log(`-- projection: ${projection.name}`);
+  console.log(createSql);
+  printed++;
+}
+
+if (filter && printed === 0) {
+  console.error(`-- no projection matched "${filter}"`);
+  process.exit(1);
+}