搭起项目骨架，验证配置文件往返

核心是确认「改配置而不弄乱文件」这件事成立：新增一路入站之后，其余 52 行逐字节不变。搬进来的改写引擎用默认输出参数时会重排整个文件——行尾注释的对齐空格消失、流式数组被加上内边距—— 连根本没改动的段落也一起波及。不修的话「改一处只动一处」这个承诺直接落空，所以关掉了它的自动排版，并在写回之后补了一步逐行还原。
2026-08-10 02:43:04 +08:00
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+import { describe, expect, it } from 'bun:test'
+import { readFileSync } from 'node:fs'
+import { join } from 'node:path'
+import { openDocument, replaceDocumentData } from '../vendor/config-editor/index.ts'
+import type { ConfigObject } from '../vendor/config-editor/index.ts'
+import { restoreInlineCommentAlignment } from './yaml-cosmetics.ts'
+
+const fixture = readFileSync(
+  join(import.meta.dir, '__fixtures__', 'config-with-comments.yaml'),
+  'utf8',
+)
+
+const clone = (v: unknown) => JSON.parse(JSON.stringify(v)) as ConfigObject
+
+/** 走一遍真实的写回链路：解析 → 改 → 写回 → 修复格式。 */
+function roundtrip(source: string, mutate: (draft: ConfigObject) => void): string {
+  const doc = openDocument(source)
+  const draft = clone(doc.data)
+  mutate(draft)
+  return restoreInlineCommentAlignment(source, replaceDocumentData(doc, draft).yaml)
+}
+
+describe('写回一份带注释的配置', () => {
+  it('原样写回时逐字节不变', () => {
+    expect(roundtrip(fixture, () => {})).toBe(fixture)
+  })
+
+  it('新增一个此前不存在的段落时，其余每一行都不变', () => {
+    const out = roundtrip(fixture, (draft) => {
+      draft.listeners = [{ name: '容器A', type: 'mixed', port: 7778, proxy: 'AUTO' }]
+    })
+
+    // 这是这个项目最核心的操作，也是取信于用户的底线：只应多出新段落，别的一行都不许动。
+    const before = fixture.split('\n')
+    const after = out.split('\n')
+    expect(after.slice(0, before.length - 1)).toEqual(before.slice(0, before.length - 1))
+    expect(out).toContain('listeners:')
+    expect(out).toContain('port: 7778')
+  })
+
+  it('改动某个段落时，不碰其它段落的注释和写法', () => {
+    const out = roundtrip(fixture, (draft) => {
+      const rules = draft.rules as string[]
+      rules[rules.length - 1] = 'MATCH,AUTO'
+    })
+
+    // rules 之外的段落必须原封不动，含对齐空格和流式数组。
+    expect(out).toContain('mixed-port: 7777          # HTTP 和 SOCKS5 共用这一个端口')
+    expect(out).toContain('  - name: PROXY                # 总开关，手动选；默认跟着 AUTO 走')
+    expect(out).toContain('    proxies: [AUTO, DIRECT]')
+    expect(out).toContain('    interval: 86400            # 每 24 小时自动拉取一次订阅')
+    expect(out).toContain('MATCH,AUTO')
+  })
+
+  it('被改动的段落内部注释会丢失，这是已知缺陷（见 ADR 0002）', () => {
+    const out = roundtrip(fixture, (draft) => {
+      const rules = draft.rules as string[]
+      rules[rules.length - 1] = 'MATCH,AUTO'
+    })
+
+    // 记录现状而非期望。将来若实现了段落内的就地修改，这条断言应当反转。
+    expect(out).not.toContain('# 本机和内网地址一律直连')
+  })
+})
+
+describe('restoreInlineCommentAlignment', () => {
+  it('内容与注释都相同时还原原本的对齐', () => {
+    const source = 'a: 1          # 说明\n'
+    const output = 'a: 1 # 说明\n'
+    expect(restoreInlineCommentAlignment(source, output)).toBe(source)
+  })
+
+  it('注释文字变了就不还原，避免掩盖真实改动', () => {
+    const source = 'a: 1          # 旧说明\n'
+    const output = 'a: 1 # 新说明\n'
+    expect(restoreInlineCommentAlignment(source, output)).toBe(output)
+  })
+
+  it('值变了就不还原', () => {
+    const source = 'a: 1          # 说明\n'
+    const output = 'a: 2 # 说明\n'
+    expect(restoreInlineCommentAlignment(source, output)).toBe(output)
+  })
+
+  it('相同的行出现多次时按顺序依次配对', () => {
+    const source = 'a: 1     # 同\nb: 2\na: 1        # 同\n'
+    const output = 'a: 1 # 同\nb: 2\na: 1 # 同\n'
+    expect(restoreInlineCommentAlignment(source, output)).toBe(source)
+  })
+
+  it('不把字符串里的井号当成注释', () => {
+    const line = 'url: "http://example.com/a#b"\n'
+    expect(restoreInlineCommentAlignment(line, line)).toBe(line)
+  })
+})