Make transport Jest-aware (#1181)

* Make transport Jest-aware

* Do not rely on env variables

lib/transport.js

@@ -4,14 +4,20 @@ const { createRequire } = require('module')
 const getCaller = require('get-caller-file')
 const { join, isAbsolute } = require('path')
 
+let onExit
+
+if (global.WeakRef && global.WeakMap && global.FinalizationRegistry) {
+  // This require MUST be top level otherwise the transport would
+  // not work from within Jest as it hijacks require.
+  onExit = require('on-exit-leak-free')
+}
+
 const ThreadStream = require('thread-stream')
 
 function setupOnExit (stream) {
   /* istanbul ignore next */
-  if (global.WeakRef && global.WeakMap && global.FinalizationRegistry) {
+  if (onExit) {
     // This is leak free, it does not leave event handlers
-    const onExit = require('on-exit-leak-free')
-
     onExit.register(stream, autoEnd)
 
     stream.on('close', function () {

package.json

@@ -23,7 +23,7 @@
     "docs": "docsify serve",
     "browser-test": "airtap --local 8080 test/browser*test.js",
     "lint": "eslint .",
-    "test": "npm run lint && tap test/*test.js test/*/*test.js && npm run test-types",
+    "test": "npm run lint && tap test/*test.js test/*/*test.js && jest test/jest && npm run test-types",
     "test-ci": "npm run lint && tap --no-check-coverage test/*test.js test/*/*test.js --coverage-report=lcovonly && npm run test-types",
     "test-ci-pnpm": "pnpm run lint && tap --no-coverage --no-check-coverage test/*test.js test/*/*test.js && pnpm run test-types",
     "test-ci-yarn-pnp": "yarn run lint && tap --no-check-coverage test/*test.js test/*/*test.js --coverage-report=lcovonly",
@@ -82,6 +82,7 @@
     "fastbench": "^1.0.1",
     "flush-write-stream": "^2.0.0",
     "import-fresh": "^3.2.1",
+    "jest": "^27.3.1",
     "log": "^6.0.0",
     "loglevel": "^1.6.7",
     "pino-pretty": "^v7.1.0",

test/jest/basic.spec.js

@@ -0,0 +1,10 @@
+/* global test */
+const pino = require('../../pino')
+
+test('transport should work in jest', function () {
+  pino({
+    transport: {
+      target: 'pino-pretty'
+    }
+  })
+})