feat(fleet): inject persona contract at launch (A3b) (#664)

packages/mosaic/src/fleet/persona-contract.spec.ts

@@ -0,0 +1,106 @@
+import { describe, it, expect, beforeEach, afterEach } from 'vitest';
+import { mkdtempSync, mkdirSync, writeFileSync, rmSync } from 'node:fs';
+import { tmpdir } from 'node:os';
+import { join } from 'node:path';
+import { readPersonaContractBlock } from './persona-contract.js';
+
+/**
+ * Persona-contract launch injection (A3b). Asserts the override-aware resolver
+ * is wired so a customized persona in roles.local/ wins at launch (AC-NS-7), and
+ * that any miss (unset/empty/unknown class, missing file) no-ops silently —
+ * never throws — mirroring readFleetCommsBlock's tolerant contract.
+ */
+
+const BASELINE_CODER = `# Coder — fleet role definition
+
+The **coder** persona (\`class: coder\`, \`domain: engineering\`).
+
+## Mandate
+
+BASELINE-MANDATE: implement the assigned lane.
+`;
+
+const OVERRIDE_CODER = `# Coder — fleet role definition (override)
+
+The **coder** persona (\`class: coder\`).
+
+## Mandate
+
+OVERRIDE-MANDATE: implement the assigned lane, the user's way.
+`;
+
+function makeHome(): string {
+  const root = mkdtempSync(join(tmpdir(), 'mosaic-persona-'));
+  return join(root, 'mosaic-home');
+}
+
+function seedBaseline(home: string, klass: string, body: string): void {
+  const dir = join(home, 'fleet', 'roles');
+  mkdirSync(dir, { recursive: true });
+  writeFileSync(join(dir, `${klass}.md`), body);
+}
+
+function seedOverride(home: string, klass: string, body: string): void {
+  const dir = join(home, 'fleet', 'roles.local');
+  mkdirSync(dir, { recursive: true });
+  writeFileSync(join(dir, `${klass}.md`), body);
+}
+
+describe('readPersonaContractBlock — launch-time persona injection (A3b)', () => {
+  let home: string;
+
+  beforeEach(() => {
+    home = makeHome();
+  });
+
+  afterEach(() => {
+    // root is the parent of mosaic-home
+    rmSync(join(home, '..'), { recursive: true, force: true });
+  });
+
+  it('injects the baseline persona when the class has a fleet/roles/<class>.md', () => {
+    seedBaseline(home, 'coder', BASELINE_CODER);
+    const block = readPersonaContractBlock(home, 'coder');
+    expect(block).toContain('# Persona Contract (coder)');
+    expect(block).toContain('BASELINE-MANDATE');
+    expect(block).toContain('baseline `fleet/roles/` layer');
+  });
+
+  it('OVERRIDE WINS: roles.local/<class>.md content is injected over the baseline (AC-NS-7)', () => {
+    seedBaseline(home, 'coder', BASELINE_CODER);
+    seedOverride(home, 'coder', OVERRIDE_CODER);
+    const block = readPersonaContractBlock(home, 'coder');
+    expect(block).toContain('# Persona Contract (coder)');
+    expect(block).toContain('OVERRIDE-MANDATE'); // override body present
+    expect(block).not.toContain('BASELINE-MANDATE'); // baseline NOT used
+    expect(block).toContain('roles.local'); // layer note names the override layer
+  });
+
+  it('injects an override-only (user-added) persona with no baseline at all', () => {
+    seedOverride(home, 'reviewer', '# Reviewer\n\n(`class: reviewer`)\n\nCUSTOM-ROLE.\n');
+    const block = readPersonaContractBlock(home, 'reviewer');
+    expect(block).toContain('# Persona Contract (reviewer)');
+    expect(block).toContain('CUSTOM-ROLE');
+  });
+
+  it('no-ops (empty string) when the class is undefined', () => {
+    seedBaseline(home, 'coder', BASELINE_CODER);
+    expect(readPersonaContractBlock(home, undefined)).toBe('');
+  });
+
+  it('no-ops (empty string) when the class is empty/whitespace', () => {
+    seedBaseline(home, 'coder', BASELINE_CODER);
+    expect(readPersonaContractBlock(home, '')).toBe('');
+    expect(readPersonaContractBlock(home, '   ')).toBe('');
+  });
+
+  it('no-ops (empty string) for an unknown class with no role file', () => {
+    seedBaseline(home, 'coder', BASELINE_CODER);
+    expect(readPersonaContractBlock(home, 'nonexistent')).toBe('');
+  });
+
+  it('no-ops (empty string, no throw) when no roles directories exist at all', () => {
+    expect(() => readPersonaContractBlock(home, 'coder')).not.toThrow();
+    expect(readPersonaContractBlock(home, 'coder')).toBe('');
+  });
+});