p0 line landing: coord board/roll + wrapper usage contract + dispatch layer (successor to #1467) (#1468)

Co-authored-by: orch-01 <[email protected]>

packages/mosaic/src/commands/watch.spec.ts

@@ -0,0 +1,72 @@
+import { mkdirSync, mkdtempSync } from 'node:fs';
+import { tmpdir } from 'node:os';
+import { join } from 'node:path';
+
+import { Command } from 'commander';
+import { afterEach, describe, expect, it } from 'vitest';
+
+import { exitStatusFor, registerWatchCommand, resolveAgentWatchTool } from './watch.js';
+
+// The dispatch command execs a real process with inherited stdio; the spec
+// covers the pure resolution and exit-mapping surfaces plus the absent-tool
+// path (which exits without spawning). Live pass-through is exercised by the
+// fleet smoke test against the real brain tool.
+
+describe('resolveAgentWatchTool', () => {
+  const saved = process.env['MOSAIC_BRAIN_HOME'];
+  afterEach(() => {
+    if (saved === undefined) delete process.env['MOSAIC_BRAIN_HOME'];
+    else process.env['MOSAIC_BRAIN_HOME'] = saved;
+  });
+
+  it('honors MOSAIC_BRAIN_HOME over the canonical brain', () => {
+    const tmp = mkdtempSync(join(tmpdir(), 'watch-resolve-'));
+    process.env['MOSAIC_BRAIN_HOME'] = tmp;
+    expect(resolveAgentWatchTool('/nonexistent/mosaic-home')).toBe(
+      join(tmp, 'tools', 'agent-watch', 'agent-watch.sh'),
+    );
+  });
+
+  it('resolves inside the brain tools tree', () => {
+    const tmp = mkdtempSync(join(tmpdir(), 'watch-resolve-'));
+    process.env['MOSAIC_BRAIN_HOME'] = tmp;
+    const tool = resolveAgentWatchTool(tmp);
+    expect(tool.endsWith(join('tools', 'agent-watch', 'agent-watch.sh'))).toBe(true);
+  });
+});
+
+describe('exitStatusFor', () => {
+  it('maps absent tool to 127', () => {
+    expect(exitStatusFor({ status: 0 }, false)).toBe(127);
+  });
+
+  it('passes the tool exit status through', () => {
+    expect(exitStatusFor({ status: 2 }, true)).toBe(2);
+    expect(exitStatusFor({ status: 78 }, true)).toBe(78);
+  });
+
+  it('maps signal death / null status to 125', () => {
+    expect(exitStatusFor({ status: null }, true)).toBe(125);
+  });
+});
+
+describe('registerWatchCommand absent-tool path', () => {
+  const saved = process.env['MOSAIC_BRAIN_HOME'];
+  afterEach(() => {
+    if (saved === undefined) delete process.env['MOSAIC_BRAIN_HOME'];
+    else process.env['MOSAIC_BRAIN_HOME'] = saved;
+    process.exitCode = undefined;
+  });
+
+  it('sets exitCode 127 with the resolved path when the tool is missing', async () => {
+    const tmp = mkdtempSync(join(tmpdir(), 'watch-missing-'));
+    // The suite directory exists but the tool file does not.
+    mkdirSync(join(tmp, 'tools', 'agent-watch'), { recursive: true });
+    process.env['MOSAIC_BRAIN_HOME'] = tmp;
+
+    const program = new Command();
+    registerWatchCommand(program);
+    await program.parseAsync(['watch', 'list'], { from: 'user' });
+    expect(process.exitCode).toBe(127);
+  });
+});