test: generate the external module fixture instead of copying ignored build output

The test proving that migrations of a module installed outside the repository
are discovered, while Core's come from the platform, copied templates/module
including dist/. dist/ is gitignored and never committed. CI runs `pnpm test`
before any build of the template, where only the template's own UI test may
have written dist/ui, dist/display, and dist/contributions, so discovery
failed with MODULE_ENTRYPOINT_MISSING for ./dist/server/index.js and
./dist/schema/index.js (and, had the UI test not run yet, the copy itself
would have failed). Locally a previous `pnpm build` had left dist/ complete.

The test now generates a minimal valid installed module in a temporary
directory with createMigrationModule, moved unchanged from the migration
discovery test into core/tests/support so both share it. It depends on no
build output, ignored file, or node_modules. It also asserts more precisely:
the module directory is outside the repository, Core's migrations match the
platform's own core/drizzle inventory by identity and checksum, and the
module's migration matches the SQL that was installed.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

core/tests/support/migration-module-fixture.ts

@@ -0,0 +1,171 @@
+import { mkdir, writeFile } from "node:fs/promises";
+import path from "node:path";
+
+/**
+ * A minimal, valid installed module written into a directory the caller owns: `package.json`,
+ * `ekklesia.module.json`, a compiled-ESM server stub at `dist/server/index.js`, and, unless
+ * disabled, a native Drizzle migration directory (journal, `_ekklesia.json` policy, snapshot chain,
+ * and SQL) that passes Core's migration discovery.
+ *
+ * Everything is generated here, from nothing in the repository: no build output, no ignored file,
+ * and no `node_modules`. Migration discovery imports no module code, so the stub is never run.
+ */
+
+export const originSnapshotId = "00000000-0000-0000-0000-000000000000";
+
+export interface MigrationFixture {
+  readonly breakpoints?: boolean;
+  readonly destructive?:
+    | { readonly mode: "none" }
+    | { readonly mode: "approval-required"; readonly reason: string };
+  readonly snapshotId?: string;
+  readonly sql: string | Uint8Array;
+  readonly tag: string;
+  readonly timestamp?: number;
+}
+
+export interface MigrationModuleFixture {
+  readonly dependencies?: Record<string, unknown>;
+  readonly manifest?: Record<string, unknown>;
+  readonly migrations?: readonly MigrationFixture[] | false;
+  readonly schemaSource?: string;
+  readonly serverSource?: string;
+}
+
+export interface CreatedMigrationModule {
+  readonly migrationDirectory?: string;
+  readonly moduleDirectory: string;
+}
+
+export function snapshotId(index: number): string {
+  return `10000000-0000-4000-8000-${(index + 1).toString(16).padStart(12, "0")}`;
+}
+
+export function manifestFor(
+  id: string,
+  options: {
+    readonly dependencies?: Record<string, unknown>;
+    readonly migrations?: boolean;
+    readonly schema?: boolean;
+  } = {},
+): Record<string, unknown> {
+  return {
+    manifestVersion: 7,
+    id,
+    name: `${id} module`,
+    version: "0.1.0",
+    compatibility: { platform: "^0.1.0", moduleSdk: "^0.1.0" },
+    ...(options.dependencies ? { dependencies: options.dependencies } : {}),
+    capabilities: [],
+    permissions: [],
+    entrypoints: {
+      server: "./dist/server/index.js",
+      ...(options.schema ? { schema: "./dist/schema/index.js" } : {}),
+      ...(options.migrations === false ? {} : { migrations: "./drizzle" }),
+    },
+  };
+}
+
+export function defaultMigrations(id: string): readonly MigrationFixture[] {
+  return [
+    {
+      sql: `CREATE TABLE "${id.replaceAll("-", "_")}_records" ("id" integer);\n`,
+      tag: "0000_initial",
+    },
+  ];
+}
+
+export async function createMigrationModule(
+  modulesDirectory: string,
+  id: string,
+  fixture: MigrationModuleFixture = {},
+): Promise<CreatedMigrationModule> {
+  const migrations =
+    fixture.migrations === false ? undefined : (fixture.migrations ?? defaultMigrations(id));
+  const moduleDirectory = path.join(modulesDirectory, id);
+  const migrationDirectory = migrations ? path.join(moduleDirectory, "drizzle") : undefined;
+  await mkdir(path.join(moduleDirectory, "dist/server"), { recursive: true });
+  if (fixture.schemaSource !== undefined) {
+    await mkdir(path.join(moduleDirectory, "dist/schema"), { recursive: true });
+  }
+  if (migrationDirectory) {
+    await mkdir(path.join(migrationDirectory, "meta"), { recursive: true });
+  }
+
+  await Promise.all([
+    writeFile(
+      path.join(moduleDirectory, "package.json"),
+      JSON.stringify({
+        name: `@test/module-${id}`,
+        version: "0.1.0",
+        type: "module",
+        ekklesia: { layer: "module" },
+      }),
+    ),
+    writeFile(
+      path.join(moduleDirectory, "ekklesia.module.json"),
+      JSON.stringify(
+        fixture.manifest ??
+          manifestFor(id, {
+            ...(fixture.dependencies ? { dependencies: fixture.dependencies } : {}),
+            migrations: migrations !== undefined,
+            schema: fixture.schemaSource !== undefined,
+          }),
+      ),
+    ),
+    writeFile(
+      path.join(moduleDirectory, "dist/server/index.js"),
+      fixture.serverSource ?? `export default { id: ${JSON.stringify(id)}, version: "0.1.0" };`,
+    ),
+    ...(fixture.schemaSource === undefined
+      ? []
+      : [writeFile(path.join(moduleDirectory, "dist/schema/index.js"), fixture.schemaSource)]),
+  ]);
+
+  if (!migrationDirectory || !migrations) {
+    return { moduleDirectory };
+  }
+
+  const journalEntries = migrations.map((migration, index) => ({
+    idx: index,
+    version: "7",
+    when: migration.timestamp ?? 1_700_000_000_000 + index,
+    tag: migration.tag,
+    breakpoints: migration.breakpoints ?? true,
+  }));
+  const policyEntries = migrations.map((migration) => ({
+    tag: migration.tag,
+    destructive: migration.destructive ?? { mode: "none" },
+  }));
+  await Promise.all([
+    writeFile(
+      path.join(migrationDirectory, "meta/_journal.json"),
+      JSON.stringify({ version: "7", dialect: "postgresql", entries: journalEntries }),
+    ),
+    writeFile(
+      path.join(migrationDirectory, "meta/_ekklesia.json"),
+      JSON.stringify({ version: 1, moduleId: id, entries: policyEntries }),
+    ),
+    ...migrations.flatMap((migration, index) => {
+      const idForSnapshot = migration.snapshotId ?? snapshotId(index);
+      const previousId =
+        index === 0
+          ? originSnapshotId
+          : (migrations[index - 1]?.snapshotId ?? snapshotId(index - 1));
+      return [
+        writeFile(path.join(migrationDirectory, `${migration.tag}.sql`), migration.sql),
+        writeFile(
+          path.join(migrationDirectory, `meta/${index.toString().padStart(4, "0")}_snapshot.json`),
+          JSON.stringify({
+            version: "7",
+            dialect: "postgresql",
+            id: idForSnapshot,
+            prevId: previousId,
+          }),
+        ),
+      ];
+    }),
+  ]);
+
+  return { migrationDirectory, moduleDirectory };
+}