test(B-0156): add bun test for tools/profile.ts CLI dispatch

tools/profile.test.ts

@@ -0,0 +1,93 @@
+// profile.test.ts — smoke tests for the DBSP profiling helper CLI.
+//
+// Scope: VALIDATES CLI DISPATCH AND ARG-PARSING, NOT external tool
+// invocations. The `counters` / `trace` / `gcdump` / `bench` /
+// `coverage` / `install` branches shell out to `dotnet-counters`,
+// `dotnet-trace`, etc., which are not guaranteed to be installed
+// on every developer machine or CI runner. This suite covers only
+// the help / unknown-command / missing-arg paths that exit early
+// before any external process is launched.
+//
+// Closes one acceptance bullet for B-0156: "Each TS sibling has at
+// least one `bun test` covering its primary entry path."
+
+import { describe, expect, test } from "bun:test";
+import { spawnSync } from "node:child_process";
+import { dirname, resolve } from "node:path";
+import { fileURLToPath } from "node:url";
+
+const PROFILE_TS = resolve(
+  dirname(fileURLToPath(import.meta.url)),
+  "profile.ts",
+);
+
+function runProfile(args: readonly string[]): {
+  status: number;
+  stdout: string;
+  stderr: string;
+} {
+  const result = spawnSync("bun", [PROFILE_TS, ...args], {
+    encoding: "utf8",
+    timeout: 10_000,
+  });
+  return {
+    status: result.status ?? -1,
+    stdout: result.stdout ?? "",
+    stderr: result.stderr ?? "",
+  };
+}
+
+describe("tools/profile.ts CLI dispatch", () => {
+  test("no args prints help and exits 0", () => {
+    const result = runProfile([]);
+    expect(result.status).toBe(0);
+    expect(result.stdout).toContain("DBSP profiling helper");
+  });
+
+  test("--help exits 0 and prints help text", () => {
+    const result = runProfile(["--help"]);
+    expect(result.status).toBe(0);
+    expect(result.stdout).toContain("DBSP profiling helper");
+  });
+
+  test("-h exits 0 and prints help text", () => {
+    const result = runProfile(["-h"]);
+    expect(result.status).toBe(0);
+    expect(result.stdout).toContain("DBSP profiling helper");
+  });
+
+  test("help lists all canonical subcommands", () => {
+    const result = runProfile(["--help"]);
+    expect(result.status).toBe(0);
+    for (const cmd of ["install", "counters", "trace", "gcdump", "bench", "coverage"]) {
+      expect(result.stdout).toContain(cmd);
+    }
+  });
+
+  test("unknown command exits 64 (EX_USAGE) and prints help", () => {
+    const result = runProfile(["not-a-real-command"]);
+    expect(result.status).toBe(64);
+    expect(result.stdout).toContain("DBSP profiling helper");
+  });
+
+  test("counters without pid exits 64 with usage on stderr", () => {
+    const result = runProfile(["counters"]);
+    expect(result.status).toBe(64);
+    expect(result.stderr).toContain("usage:");
+    expect(result.stderr).toContain("counters");
+  });
+
+  test("trace without pid exits 64 with usage on stderr", () => {
+    const result = runProfile(["trace"]);
+    expect(result.status).toBe(64);
+    expect(result.stderr).toContain("usage:");
+    expect(result.stderr).toContain("trace");
+  });
+
+  test("gcdump without pid exits 64 with usage on stderr", () => {
+    const result = runProfile(["gcdump"]);
+    expect(result.status).toBe(64);
+    expect(result.stderr).toContain("usage:");
+    expect(result.stderr).toContain("gcdump");
+  });
+});

tsconfig.json

@@ -19,7 +19,7 @@
     "isolatedModules": true,
     "moduleDetection": "force",
     "skipLibCheck": true,
-    "types": ["bun"]
+    "types": ["bun", "bun-types"]
   },
   "include": ["**/*.ts"],
   "exclude": [