fix: store unref promises for awaiting in tests

lib/npm.js

@@ -28,6 +28,7 @@ class Npm {
     return require(`./commands/${command}.js`)
   }
 
+  unrefPromises = []
   updateNotification = null
   argv = []
 
@@ -224,11 +225,16 @@ class Npm {
       log.verbose('argv', this.#argvClean.map(JSON.stringify).join(' '))
     })
 
-    this.#logFile.load({
+    // logFile.load returns a promise that resolves when old logs are done being cleaned.
+    // We save this promise to an array so that we can await it in tests to ensure more
+    // deterministic logging behavior. The process will also hang open if this were to
+    // take a long time to resolve, but that is why process.exit is called explicitly
+    // in the exit-handler.
+    this.unrefPromises.push(this.#logFile.load({
       path: this.logPath,
       logsMax: this.config.get('logs-max'),
       timing: this.config.get('timing'),
-    })
+    }))
 
     this.#timers.load({
       path: this.logPath,

test/fixtures/mock-npm.js

@@ -73,6 +73,17 @@ const getMockNpm = async (t, { mocks, init, load, npm: npmOpts }) => {
       })
     }
 
+    async load () {
+      const res = await super.load()
+      // Wait for any promises (currently only log file cleaning) to be
+      // done before returning from load in tests. This helps create more
+      // deterministic testing behavior because in reality that promise
+      // is left hanging on purpose as a best-effort and the process gets
+      // closed regardless of if it has finished or not.
+      await Promise.all(this.unrefPromises)
+      return res
+    }
+
     async exec (...args) {
       const [res, err] = await super.exec(...args).then((r) => [r]).catch(e => [null, e])
       // This mimics how the exit handler flushes output for commands that have

test/lib/cli/exit-handler.js

@@ -129,8 +129,6 @@ t.test('handles unknown error with logs and debug file', async (t) => {
   })
 
   await exitHandler(err('Unknown error', 'ECODE'))
-  // force logfile cleaning logs to happen since those are purposefully not awaited
-  await require('timers/promises').setTimeout(200)
 
   const fileLogs = await debugFile()
   const fileLines = fileLogs.split('\n')
@@ -140,19 +138,14 @@ t.test('handles unknown error with logs and debug file', async (t) => {
 
   t.equal(process.exitCode, 1)
 
-  let skippedLogs = 0
   logs.forEach((logItem, i) => {
     const logLines = logItem.split('\n').map(l => `${i} ${l}`)
     for (const line of logLines) {
-      if (line.includes('logfile') && line.includes('cleaning')) {
-        skippedLogs++
-        continue
-      }
       t.match(fileLogs.trim(), line, 'log appears in debug file')
     }
   })
 
-  t.equal(logs.length - skippedLogs, parseInt(lastLog) + 1)
+  t.equal(logs.length, parseInt(lastLog) + 1)
   t.match(logs.error, [
     'code ECODE',
     'ERR SUMMARY Unknown error',