fix: add tools reorder to system prompt

packages/core/system-prompt/tests/tool-order.spec.ts

@@ -0,0 +1,90 @@
+import { describe, expect, it } from 'vitest'
+import { Context } from 'cordis'
+import SystemPrompt, { PromptAssembly, TOOL_ORDER_REST } from '@deepseek-ai/dsh-system-prompt'
+import type { ToolSchema } from '@deepseek-ai/dsh-llm'
+
+function tool(name: string, description = name): ToolSchema {
+  return { name, description, parameters: { type: 'object', properties: {} } }
+}
+
+async function mount(config: { persona?: string; toolOrder?: string[] } = {}): Promise<Context> {
+  const ctx = new Context()
+  await ctx.plugin(SystemPrompt, config)
+  return ctx
+}
+
+function names(assembly: PromptAssembly): string[] {
+  return assembly.tools.map(t => t.name)
+}
+
+describe('SystemPrompt tool order', () => {
+  it('exports the rest entry as "..."', () => {
+    expect(TOOL_ORDER_REST).toBe('...')
+  })
+
+  it('assembles tools in lexicographic name order when no toolOrder is configured', async () => {
+    const ctx = await mount()
+    ctx.systemPrompt.tools(() => [tool('charlie'), tool('alpha')])
+    ctx.systemPrompt.tools(() => [tool('bravo')])
+    expect(names(await ctx.systemPrompt.assemble())).toEqual(['alpha', 'bravo', 'charlie'])
+  })
+
+  it('assembles the same order regardless of provider registration order', async () => {
+    const forward = await mount()
+    forward.systemPrompt.tools(() => [tool('alpha')])
+    forward.systemPrompt.tools(() => [tool('zulu')])
+    const backward = await mount()
+    backward.systemPrompt.tools(() => [tool('zulu')])
+    backward.systemPrompt.tools(() => [tool('alpha')])
+    expect(names(await forward.systemPrompt.assemble())).toEqual(['alpha', 'zulu'])
+    expect(names(await backward.systemPrompt.assemble())).toEqual(['alpha', 'zulu'])
+  })
+
+  it('applies a configured toolOrder: listed positions, rest at "..." lexicographically, absent names ignored', async () => {
+    const ctx = await mount({ toolOrder: ['todo_write', 'ghost', TOOL_ORDER_REST, 'bash'] })
+    ctx.systemPrompt.tools(() => [tool('bash'), tool('echo_b'), tool('todo_write'), tool('echo_a')])
+    expect(names(await ctx.systemPrompt.assemble())).toEqual(['todo_write', 'echo_a', 'echo_b', 'bash'])
+  })
+
+  it('keeps collection order between tools that share a name (stable sort)', async () => {
+    const ctx = await mount()
+    ctx.systemPrompt.tools(() => [tool('dup', 'first'), tool('anchor'), tool('dup', 'second')])
+    const assembly = await ctx.systemPrompt.assemble()
+    expect(assembly.tools.map(t => t.description)).toEqual(['anchor', 'first', 'second'])
+  })
+
+  it('canonicalizes BEFORE the assemble waterfall: listeners see the ordered list and own their own edits', async () => {
+    const ctx = await mount()
+    ctx.systemPrompt.tools(() => [tool('zulu'), tool('alpha')])
+    let seen: string[] | undefined
+    ctx.on('system-prompt/assemble', function (assembly, _context, next) {
+      seen = assembly.tools.map(t => t.name)
+      // A listener-appended tool is NOT re-sorted — same contract as sections:
+      // canonicalization applies to what the registry contributed, and a
+      // listener owns the determinism of what it emits.
+      assembly.tools.push(tool('aardvark'))
+      return next()
+    })
+    const assembly = await ctx.systemPrompt.assemble()
+    expect(seen).toEqual(['alpha', 'zulu'])
+    expect(names(assembly)).toEqual(['alpha', 'zulu', 'aardvark'])
+  })
+
+  it.each([
+    ['an empty list', []],
+    ['a list without the rest entry', ['bash', 'todo_write']],
+  ])('rejects %s at load (the "..." rest entry is required)', async (_case, toolOrder) => {
+    await expect(new Context().plugin(SystemPrompt, { toolOrder })).rejects.toThrow('must contain the "..." rest entry')
+  })
+
+  it.each([
+    ['a duplicate tool name', ['bash', 'bash', TOOL_ORDER_REST]],
+    ['a duplicate rest entry', [TOOL_ORDER_REST, 'bash', TOOL_ORDER_REST]],
+  ])('rejects %s at load', async (_case, toolOrder) => {
+    await expect(new Context().plugin(SystemPrompt, { toolOrder })).rejects.toThrow('more than once')
+  })
+
+  it('throws from direct construction too', () => {
+    expect(() => new SystemPrompt(new Context(), { toolOrder: ['bash'] })).toThrow('rest entry')
+  })
+})