run on process

Author: motdotla

CHANGELOG.md

@@ -4,6 +4,10 @@ All notable changes to this project are documented in this file.
 
 ## [Unreleased](https://github.com/dotenvx/react-native-dotenv/compare/v4.1.0...main)
 
+### Changed
+
+- Log `◇ injected env` once per process so Metro does not spam it on every file when `api.cache(false)`.
+
 ## [4.1.0](https://github.com/dotenvx/react-native-dotenv/compare/v4.0.0...v4.1.0) (2026-07-28)
 
 ### Added

README.md

@@ -54,7 +54,9 @@ On transform you'll see a message on stderr (same style as dotenv):
 ◇ injected env (2) from .env
 ```
 
-Set `quiet: true` in the plugin options to suppress it.
+Metro may prefix worker logs with `|`. Expo also prints its own `env: load .env` line — that is Expo's built-in loader, not this plugin.
+
+Set `quiet: true` in the plugin options to suppress the `◇ injected env` message.
 
  
 

index.js

@@ -16,13 +16,22 @@ function parseDotenvFile (filepath, verbose = false) {
   }
 }
 
+// Babel may re-instantiate this plugin per file (e.g. api.cache(false)). Log once
+// per process for the same message so Metro workers do not spam stderr.
+const loggedInjectMessages = new Set()
+
 function logInjectedEnv (fileEnv, loadedPaths) {
   const keysCount = Object.keys(fileEnv).length
-  if (loadedPaths.length > 0) {
-    console.error(`◇ injected env (${keysCount}) from ${loadedPaths.join(', ')}`)
-  } else {
-    console.error(`◇ injected env (${keysCount})`)
+  const message = loadedPaths.length > 0
+    ? `◇ injected env (${keysCount}) from ${loadedPaths.join(', ')}`
+    : `◇ injected env (${keysCount})`
+
+  if (loggedInjectMessages.has(message)) {
+    return
   }
+
+  loggedInjectMessages.add(message)
+  console.error(message)
 }
 
 function undefObjectAssign (targetObject, sourceObject) {

tests/index.test.js

@@ -50,6 +50,20 @@ describe('react-native-dotenv', () => {
     expect(console.error.mock.calls.some(call => /^◇ injected env \(\d+\) from /.test(String(call[0])))).toBe(true)
   })
 
+  it('should log injected env only once per process', () => {
+    jest.resetModules()
+    const plugin = require('../index.js')
+    const babelOpts = {
+      configFile: false,
+      babelrc: false,
+      plugins: [[plugin, { path: FIXTURES + 'default/.env' }]]
+    }
+    transformSync('import { API_KEY } from "@env"', babelOpts)
+    transformSync('import { API_KEY } from "@env"', babelOpts)
+    const injectLogs = console.error.mock.calls.filter(call => String(call[0]).includes('injected env'))
+    expect(injectLogs).toHaveLength(1)
+  })
+
   it('should not log injected env when quiet', () => {
     jest.resetModules()
     transformSync('import { API_KEY } from "@env"', {