refactor(cli): centralize process lifecycle

packages/cli/src/utils/commandResult.test.ts

@@ -0,0 +1,35 @@
+import { afterEach, describe, expect, it } from "vitest";
+import {
+  CliResultSignal,
+  CliRuntimeError,
+  CliUsageError,
+  consumeCommandResult,
+  failCommand,
+  failUsage,
+  finishCommand,
+  requestCliExit,
+  setCommandResult,
+} from "./commandResult.js";
+
+afterEach(() => {
+  consumeCommandResult();
+});
+
+describe("command result contract", () => {
+  it("keeps a failure from being overwritten by a later success", () => {
+    setCommandResult({ exitCode: 1, kind: "runtime_error", presented: true });
+    setCommandResult({ exitCode: 0, kind: "success" });
+    expect(consumeCommandResult().exitCode).toBe(1);
+  });
+
+  it("represents fatal and early-success control flow without process.exit", () => {
+    expect(() => failCommand(2)).toThrow(CliRuntimeError);
+    expect(() => failUsage(2)).toThrow(CliUsageError);
+    expect(() => finishCommand()).toThrow(CliResultSignal);
+  });
+
+  it("records a requested exit when no root handler is registered", () => {
+    requestCliExit(1);
+    expect(consumeCommandResult()).toMatchObject({ exitCode: 1, kind: "runtime_error" });
+  });
+});