[Fix] 稳定 prompt pick 选择结果

[liuwanwan1]

关联 Issue

Fixes #877

问题

{pick(...)} 之前和 {random(...)} 一样每次渲染都走 Math.random()，同一会话中的系统提示、作者注记或用户提示可能在连续请求里选到不同分支，导致角色语气、称呼或提示词约束漂移。

修复内容

• 为 selectFromList 增加稳定种子参数。
• pick 使用会话/对话上下文和候选列表生成 SHA-1 哈希，稳定映射到同一个候选值。
• 保持 random 原有随机行为不变。
• 增加 selectFromList 的稳定选择测试。

验证

• COREPACK_HOME=/tmp/corepack corepack yarn fast-build shared-prompt-renderer
• COREPACK_HOME=/tmp/corepack corepack yarn fast-build core
• COREPACK_HOME=/tmp/corepack corepack yarn mocha -r tsconfig-paths/register -r esbuild-register -r yml-register --exit packages/core/tests/conversation-utils.spec.ts
• COREPACK_HOME=/tmp/corepack corepack yarn eslint packages/core/src/services/prompt_renderer.ts packages/core/src/utils/string.ts

补充说明：全量 COREPACK_HOME=/tmp/corepack corepack yarn test 当前有 10 个既有失败，失败点在归档、回滚、测试桩和缺失的 extension-agent 文件路径；本次新增的 selectFromList 用例在全量输出和单文件测试中均通过。

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

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⚙️ Run configuration

Configuration used: Repository UI

Review profile: CHILL

Plan: Pro

Run ID: bff95e75-391e-4bf4-9891-e3fa0fb8b893

📥 Commits

Reviewing files that changed from the base of the PR and between ff6455b and b91e21a.

📒 Files selected for processing (1)

• packages/core/src/utils/string.ts

---

Walkthrough

将 {pick(...)} 从每次随机选择改为会话/种子感知的稳定选择：在 selectFromList 中加入可选 seed 并用 SHA‑1 哈希产生确定性索引；在 Prompt renderer 中根据 cfg 的 conversationId 传入 seed；相关测试已补充。

Changes

Pick 函数稳定选择

Layer / File(s)	Summary
SHA-1 哈希稳定选择算法 packages/core/src/utils/string.ts, packages/core/tests/conversation-utils.spec.ts	selectFromList 新增可选 seed 参数；当 isPick 为真时对 ${seed}:${args} 计算 SHA‑1，并用 hash.readUInt32BE(0) % items.length 确定选择索引，取代 Math.random()；新增测试验证在相同 seed 下结果稳定、不同 seed 下结果可变。
Prompt renderer 会话上下文集成 packages/core/src/services/prompt_renderer.ts, packages/core/tests/conversation-utils.spec.ts	ChatLunaPromptRenderService 中的 pick 内置函数改为接收 (args, _variables, cfg)，并将 cfg?.conversationId ?? '' 作为 seed 传入 selectFromList；新增渲染测试覆盖未提供可配置项与提供 configurable.conversationId 两种情形。

Sequence Diagram

sequenceDiagram
  participant PromptRenderer
  participant PickFunction
  participant SelectFromList
  participant SHA1
  PromptRenderer->>PickFunction: call pick(args, _variables, cfg)
  PickFunction->>SelectFromList: selectFromList(args.join(','), true, cfg?.conversationId ?? '')
  SelectFromList->>SHA1: compute SHA-1(`${seed}:${args}`)
  SHA1->>SelectFromList: return hash bytes
  SelectFromList->>SelectFromList: idx = readUInt32BE(0) % items.length
  SelectFromList->>PromptRenderer: return selected item

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Estimated code review effort

🎯 3 (Moderate) | ⏱️ ~20 minutes

Poem

🐰 兔子说：欢呼吧，pick 变稳了！
种子拼接会话名，哈希敲定取哪一格。
同一对话，选择不再跑偏；
不同会话，仍各自为政。
胡萝卜稳固，我也安然。

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Title check	✅ Passed	PR标题准确概括了主要改动：为pick函数实现稳定选择而非随机选择，与代码变更内容高度相关。
Description check	✅ Passed	PR描述详细说明了问题、修复内容、测试验证步骤，与changeset直接相关，信息量充分。
Linked Issues check	✅ Passed	代码变更完整满足issue #877的所有需求：pick使用稳定种子实现确定性选择，random保持随机，包含完整测试覆盖。
Out of Scope Changes check	✅ Passed	所有代码变更均直接针对issue #877中pick稳定性问题，包括selectFromList参数扩展、pick处理器调用修改、测试用例补充，无范围外修改。
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.

_{✏️ Tip: You can configure your own custom pre-merge checks in the settings.}

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• Create PR with unit tests

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[gemini-code-assist]

Code Review

This pull request implements stable selection for the pick function provider by introducing a seed-based hashing mechanism in selectFromList. The seed is derived from session and conversation metadata to ensure deterministic output. A critical issue was identified in prompt_renderer.ts where accessing properties on an optional configuration object could lead to runtime crashes; using optional chaining was suggested to mitigate this risk.

[liuwanwan1]

已根据 Gemini Code Assist 的建议补充处理：

• pick 回调改为通过可选链读取 cfg 与 variables.built，避免无 render options 时运行时报错
• 增加 prompt pick renders without configurable options 回归测试

本地验证：

• COREPACK_HOME=/tmp/corepack corepack yarn mocha -r tsconfig-paths/register -r esbuild-register -r yml-register --exit packages/core/tests/conversation-utils.spec.ts（11 passing）
• COREPACK_HOME=/tmp/corepack corepack yarn eslint packages/core/src/services/prompt_renderer.ts packages/core/src/utils/string.ts
• COREPACK_HOME=/tmp/corepack corepack yarn fast-build core

[liuwanwan1]

确实，这里原来的实现想得太宽了。

我已经把 seed 收敛到 configurable.conversationId，不再拼 session 上的一堆字段；那两个 as 也一起去掉了。现在逻辑会简单一些：有 conversationId 时按会话稳定选择，没有的话就按空 seed 稳定选择。

另外补了两个用例，覆盖无 configurable 和有 conversationId 的情况。本地单文件测试是 12 passing，fast-build core 和相关 eslint 也过了。

[liuwanwan1]

这个也改掉了：调用处不再 String(...)，直接把 cfg?.conversationId ?? "" 传进去；selectFromList 这边接收 seed 后用模板字符串参与 hash。相关测试和 core build 也重新跑过了。

[liuwanwan1]

大佬我先睡啦，早点休息

[dingyi222666]

A conversation must be resolved before this pull request can be merged.
Commits must have verified signatures. 你让 codex 给你配个 git 签名，重新 rebase 全部签名，push -f

[liuwanwan1]

A conversation must be resolved before this pull request can be merged.
Commits must have verified signatures. 你让 codex 给你配个 git 签名，重新 rebase 全部签名，push -f

好的佬，我明天中午做

[liuwanwan1]

已处理：

• 配置了 SSH git 签名，并把签名公钥加到了 GitHub signing keys
• 基于最新 upstream/v1-dev 重新 rebase 了 PR 的 4 个提交，全部已带 verified signature
• 已 force push 到 fix/stable-pick-renderer
• 之前的 3 个 review conversations 也已 resolve

当前 GitHub API 显示 4 个 commit verification 都是 valid。

[coderabbitai]

Actionable comments posted: 1

🤖 Prompt for all review comments with AI agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

Inline comments:
In `@packages/core/src/utils/string.ts`:
- Around line 320-324: Change the selectFromList signature to require seed be a
string (not unknown) so the function contract matches actual usage; update the
parameter in the export of selectFromList (the seed parameter default can remain
''), and adjust any callers or tests if they were passing non-strings so they
cast/convert to string before calling; this makes the template literal
`${seed}:${args}` type-safe and clearer in the selectFromList function.

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Fix all unresolved CodeRabbit comments on this PR:

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---

ℹ️ Review info

⚙️ Run configuration

Configuration used: Repository UI

Review profile: CHILL

Plan: Pro

Run ID: 5b54039d-5459-4904-8a21-85b2ac605bb1

📥 Commits

Reviewing files that changed from the base of the PR and between add62ba and ff6455b.

📒 Files selected for processing (3)

• packages/core/src/services/prompt_renderer.ts
• packages/core/src/utils/string.ts
• packages/core/tests/conversation-utils.spec.ts

[dingyi222666]

等下次版本发布的时候会跟着一起发的！建议多测一下 1.4 alpha 的 bug，稳定了我们直接发正式版了