事件生命周期

🌐 Event lifecycle

上面的表格将事件进行了分组；下面的图表则把它们放在时间线上。声明顺序的事件构成了主要脉络，有缓冲处理，这样报告器就能按来源顺序看到它们，而每个执行顺序的双胞事件会在工作实际发生时立即发出。特别是，'test:start' 标记的是测试开始报告自身及其子测试状态的时间，而不是其主体开始执行的时间；那个时刻是 'test:dequeue'。

🌐 The tables above group the events; the diagram below places them on a timeline. The declaration ordered events form the main spine, buffered so that a reporter sees them in source order, while each execution ordered twin is emitted immediately, when the work actually happens. In particular, 'test:start' marks when a test begins reporting its own and its subtests' status, not when its body begins executing; that moment is 'test:dequeue'.

                     node:test reporter event lifecycle
   main spine = DECLARATION order (buffered; matches source order)
   right side = EXECUTION order (emitted immediately); ◄ marks each twin

  LEAF TEST
  ─────────
   ┌──────────────┐                   test:enqueue
   │ test:start   │ ◄──── twins ────  (queued for execution;
   └──────────────┘                    type: 'suite' | 'test')
        │  begins REPORTING           test:dequeue
        │  (not the start of          (about to run; emitted right
        │   the test body)             before the test body runs)
        │
        │     [ between the twins, on the execution timeline, the test
        │       body runs: context.log() emits test:log live, and
        │       test:stdout / test:stderr stream with --test ]
        │
        ▼
   ┌───────────────────────┐
   │ test:pass │ test:fail │ ◄──── twin ────  test:complete
   └───────────────────────┘   result         (details.passed says which)
        │
        ▼
   test:diagnostic    the test's own context.diagnostic() messages,
                      buffered while it runs, flushed after its result


  SUITE / PARENT TEST   (each subtest is the whole LEAF flow above)
  ───────────────────
   test:start ─► [ full flow of each subtest ... ] ─►
        test:plan (count = subtests) ─► test:pass │ test:fail ─►
        test:diagnostic


  RUN-LEVEL FINALE   (root, after all top-level tests)
  ────────────────
   test:plan         top-level count
        │
        ▼
   test:diagnostic   x N   tests, suites, pass, fail, cancelled,
        │                  skipped, todo, duration_ms (+ coverage errors)
        ▼
   test:coverage     only if coverage is enabled
        │
        ▼
   test:summary  ─►  stream ends


  INTERRUPTION   (SIGINT, e.g. Ctrl+C, while tests are still running)
  ────────────
   test:interrupted   the innermost tests still running at that moment
        │             (not emitted if none were running)
        ▼
   the run exits immediately — the buffered spine never flushes, so
   neither the finale above nor those tests' own results are emitted 拷贝