test: trim test startup overhead

test/architecture-smells.test.ts

@@ -1,10 +1,26 @@
-import { execFileSync } from "node:child_process";
-import path from "node:path";
 import { describe, expect, it } from "vitest";
-import { collectArchitectureSmells } from "../scripts/check-architecture-smells.mjs";
+import { collectArchitectureSmells, main } from "../scripts/check-architecture-smells.mjs";
 
-const repoRoot = process.cwd();
-const scriptPath = path.join(repoRoot, "scripts", "check-architecture-smells.mjs");
+function createCapturedIo() {
+  let stdout = "";
+  let stderr = "";
+  return {
+    io: {
+      stdout: {
+        write(chunk) {
+          stdout += String(chunk);
+        },
+      },
+      stderr: {
+        write(chunk) {
+          stderr += String(chunk);
+        },
+      },
+    },
+    readStdout: () => stdout,
+    readStderr: () => stderr,
+  };
+}
 
 describe("architecture smell inventory", () => {
   it("produces stable sorted output", async () => {
@@ -26,11 +42,11 @@ describe("architecture smell inventory", () => {
   });
 
   it("script json output matches the collector", async () => {
-    const stdout = execFileSync(process.execPath, [scriptPath, "--json"], {
-      cwd: repoRoot,
-      encoding: "utf8",
-    });
+    const captured = createCapturedIo();
+    const exitCode = await main(["--json"], captured.io);
 
-    expect(JSON.parse(stdout)).toEqual(await collectArchitectureSmells());
+    expect(exitCode).toBe(0);
+    expect(captured.readStderr()).toBe("");
+    expect(JSON.parse(captured.readStdout())).toEqual(await collectArchitectureSmells());
   });
 });