test(support): add shared AgentLoop testkit

packages/support/README.md

@@ -5,9 +5,10 @@ Packages that exist to serve development, testing, and the examples rather than
 | Package | Role | ctx key |
 |---|---|---|
 | `acp-snapshot/` | ACP snapshot suite kit: subprocess scenario harness + golden normalizers + the `defineAcpSnapshotSuite` factory | (library — imported by example `*.snapshot.ts` suites) |
+| `agent-loop-testkit/` | Shared prerequisite mounting for tests that exercise the concrete agent loop | (library — imported by AgentLoop integration tests) |
 | `invariants/` | Runtime event-contract assertions for development diagnostics | (listens on `session/*`, `agent/*`) |
 | `loader-smoke/` | Shared real-Loader subprocess harness for keyless example smokes | (library — imported by example e2e suites) |
 | `llm-replay/` | Record/replay adapter: short-circuits `llm/stream` from a recorded session JSONL (keyless snapshot tests) | (listens on `llm/stream`) |
 | `subagent-mock/` | Scripted `SubagentProvider` for deterministic seam/tool tests | (registers on `ctx.subagents`) |
 
-`invariants` is development support but has no environment guard: it runs wherever registered, and the default `dsh-agent-spine-demo` bundle mounts it unconditionally. `llm-replay` backs the demos and the snapshot test tier under the per-file coverage gate. `acp-snapshot` carries the snapshot tier's harness/normalizer/suite machinery, while `loader-smoke` owns the parallel stdio/Loader process boundary used by keyless example e2e suites. `subagent-mock` exercises the real `ctx.subagents` load path without a model or child agent. A package graduates OUT of `support/` into a product group only when it gains documented product consumers.
+`invariants` is development support but has no environment guard: it runs wherever registered, and the default `dsh-agent-spine-demo` bundle mounts it unconditionally. `agent-loop-testkit` centralizes the mandatory service spine for hand-built AgentLoop tests without owning their loop or scenario. `llm-replay` backs the demos and the snapshot test tier under the per-file coverage gate. `acp-snapshot` carries the snapshot tier's harness/normalizer/suite machinery, while `loader-smoke` owns the parallel stdio/Loader process boundary used by keyless example e2e suites. `subagent-mock` exercises the real `ctx.subagents` load path without a model or child agent. A package graduates OUT of `support/` into a product group only when it gains documented product consumers.

packages/support/agent-loop-testkit/README.md

@@ -0,0 +1,27 @@
+# `@deepseek-ai/dsh-agent-loop-testkit`
+
+Shared prerequisite mounting for tests that exercise the concrete `AgentLoop`. `mountAgentLoopTestDependencies(ctx, options?)` installs the LLM, session, system-prompt, tool, and agent services in dependency order, then returns before the loop is mounted.
+
+The caller registers adapters and optional plugins, mounts `AgentLoop` with the configuration under test, and disposes its own Context. System-prompt and tool-registry configuration can be forwarded through `options`; the helper does not provide test defaults beyond those owned by the services. A plugin-load failure rejects the helper call, while services activated earlier in the sequence remain owned by the caller's Context.
+
+```ts
+import { Context } from 'cordis'
+import AgentLoop from '@deepseek-ai/dsh-agent-loop'
+import { mountAgentLoopTestDependencies } from '@deepseek-ai/dsh-agent-loop-testkit'
+
+const ctx = new Context()
+
+await mountAgentLoopTestDependencies(ctx)
+// Register the test adapter and any optional plugins here.
+await ctx.plugin(AgentLoop, { agents: [] })
+```
+
+Tests of injection failures, partial topology, service load order, or service teardown mount their dependencies directly instead of using this helper.
+
+## Model Experience
+
+None, as this test-only composition helper neither drives nor modifies model requests.
+
+## Known Limitations and Deferred Work
+
+- **Only the mandatory prerequisite spine is shared** — adapters, optional plugins, `AgentLoop`, agents, and Context teardown remain caller-owned so scenario-specific ordering stays visible.

packages/support/agent-loop-testkit/package.json

@@ -0,0 +1,41 @@
+{
+  "name": "@deepseek-ai/dsh-agent-loop-testkit",
+  "description": "Shared prerequisite mounting for tests that exercise the concrete agent loop",
+  "version": "0.0.1",
+  "private": true,
+  "type": "module",
+  "main": "lib/index.js",
+  "types": "lib/types/index.d.ts",
+  "exports": {
+    ".": {
+      "types": "./lib/types/index.d.ts",
+      "default": "./lib/index.js"
+    },
+    "./src/*": "./src/*",
+    "./package.json": "./package.json"
+  },
+  "files": [
+    "lib/index.js",
+    "lib/types/**/*.d.ts",
+    "lib/types/**/*.d.ts.map",
+    "src"
+  ],
+  "license": "BSD-3-Clause",
+  "peerDependencies": {
+    "@deepseek-ai/dsh-agent": "^0.0.1",
+    "@deepseek-ai/dsh-llm": "^0.0.1",
+    "@deepseek-ai/dsh-session": "^0.0.1",
+    "@deepseek-ai/dsh-system-prompt": "^0.0.1",
+    "@deepseek-ai/dsh-tools": "^0.0.1",
+    "cordis": "^4.0.0-rc.7"
+  },
+  "devDependencies": {
+    "@deepseek-ai/dsh-agent": "workspace:^",
+    "@deepseek-ai/dsh-agent-loop": "workspace:^",
+    "@deepseek-ai/dsh-llm": "workspace:^",
+    "@deepseek-ai/dsh-session": "workspace:^",
+    "@deepseek-ai/dsh-system-prompt": "workspace:^",
+    "@deepseek-ai/dsh-tools": "workspace:^",
+    "cordis": "^4.0.0-rc.7"
+  }
+}

packages/support/agent-loop-testkit/src/index.ts

@@ -0,0 +1,46 @@
+/**
+ * Shared mounting for the services required before tests load the concrete
+ * agent loop. The caller retains ownership of the context, loop, adapters,
+ * optional plugins, and teardown.
+ * @module @deepseek-ai/dsh-agent-loop-testkit
+ */
+
+import type { Context } from 'cordis'
+import AgentRegistry from '@deepseek-ai/dsh-agent'
+import LlmService from '@deepseek-ai/dsh-llm'
+import SessionStore from '@deepseek-ai/dsh-session'
+import SystemPrompt from '@deepseek-ai/dsh-system-prompt'
+import type { Config as SystemPromptConfig } from '@deepseek-ai/dsh-system-prompt'
+import ToolRegistry from '@deepseek-ai/dsh-tools'
+import type { Config as ToolRegistryConfig } from '@deepseek-ai/dsh-tools'
+
+/** Configuration forwarded to the prerequisite service plugins. */
+export interface AgentLoopTestDependenciesOptions {
+  /** Configuration for the system-prompt registry. */
+  readonly systemPrompt?: SystemPromptConfig
+  /** Configuration for the tool registry. */
+  readonly tools?: ToolRegistryConfig
+}
+
+/**
+ * Mount the standard prerequisite services for an AgentLoop test.
+ *
+ * The function deliberately does not mount AgentLoop or register an adapter,
+ * so tests retain control of load order and the topology under test. The
+ * context owns every mounted service and remains responsible for disposal. A
+ * plugin-load failure rejects the promise; services activated earlier in the
+ * sequence remain context-owned and unwind with that context.
+ * @param ctx - test context that owns the mounted services.
+ * @param options - optional service configuration forwarded without mutation.
+ * @returns after every prerequisite service has activated.
+ */
+export async function mountAgentLoopTestDependencies(
+  ctx: Context,
+  options: AgentLoopTestDependenciesOptions = {},
+): Promise<void> {
+  await ctx.plugin(LlmService)
+  await ctx.plugin(SessionStore)
+  await ctx.plugin(SystemPrompt, options.systemPrompt ?? {})
+  await ctx.plugin(ToolRegistry, options.tools ?? {})
+  await ctx.plugin(AgentRegistry)
+}

packages/support/agent-loop-testkit/tests/agent-loop-testkit.spec.ts

@@ -0,0 +1,20 @@
+import { describe, expect, it } from 'vitest'
+import { Context } from 'cordis'
+import AgentLoop from '@deepseek-ai/dsh-agent-loop'
+import { renderPrompt } from '@deepseek-ai/dsh-system-prompt'
+import { mountAgentLoopTestDependencies } from '../src/index.ts'
+
+describe('dsh-agent-loop-testkit', () => {
+  it('mounts a configurable prerequisite spine that can activate AgentLoop', async () => {
+    const ctx = new Context()
+    await mountAgentLoopTestDependencies(ctx, {
+      systemPrompt: { persona: 'Test persona.' },
+      tools: { mode: 'native' },
+    })
+
+    expect(renderPrompt(await ctx.systemPrompt.assemble())).toContain('Test persona.')
+    await expect(ctx.plugin(AgentLoop, { agents: [] })).resolves.toBeDefined()
+
+    await ctx.fiber.dispose()
+  })
+})

packages/support/agent-loop-testkit/tsconfig.json

@@ -0,0 +1,33 @@
+{
+  "extends": "../../../tsconfig.base.json",
+  "compilerOptions": {
+    "rootDir": "src",
+    "outDir": "lib/types"
+  },
+  "include": [
+    "src"
+  ],
+  "references": [
+    {
+      "path": "../../../vendor/cosmokit"
+    },
+    {
+      "path": "../../../vendor/cordis"
+    },
+    {
+      "path": "../../core/agent"
+    },
+    {
+      "path": "../../llm/llm"
+    },
+    {
+      "path": "../../core/session"
+    },
+    {
+      "path": "../../core/system-prompt"
+    },
+    {
+      "path": "../../core/tools"
+    }
+  ]
+}