From 4de44e6c523f50acff0bd9615b891ed567c2d4b9 Mon Sep 17 00:00:00 2001
From: pooya parsa <pyapar@gmail.com>
Date: Wed, 9 Sep 2020 08:50:27 +0000
Subject: [PATCH]  fix(config): avoid recursion when interpolating env (#8014)

---
 packages/config/src/load.js                 | 10 ++++++++--
 test/fixtures/runtime-config/.env           |  3 +++
 test/fixtures/runtime-config/nuxt.config.js |  3 ++-
 3 files changed, 13 insertions(+), 3 deletions(-)

diff --git a/packages/config/src/load.js b/packages/config/src/load.js
index d531ac2f92..4abb1a9eb8 100644
--- a/packages/config/src/load.js
+++ b/packages/config/src/load.js
@@ -153,7 +153,7 @@ function expand (target, source = {}, parse = v => v) {
     return source[key] !== undefined ? source[key] : target[key]
   }
 
-  function interpolate (value) {
+  function interpolate (value, parents = []) {
     if (typeof value !== 'string') {
       return value
     }
@@ -171,10 +171,16 @@ function expand (target, source = {}, parse = v => v) {
         const key = parts[2]
         replacePart = parts[0].substring(prefix.length)
 
+        // Avoid recursion
+        if (parents.includes(key)) {
+          consola.warn(`Please avoid recursive environment variables ( loop: ${parents.join(' > ')} > ${key} )`)
+          return ''
+        }
+
         value = getValue(key)
 
         // Resolve recursive interpolations
-        value = interpolate(value)
+        value = interpolate(value, [...parents, key])
       }
 
       return value !== undefined ? newValue.replace(replacePart, value) : newValue
diff --git a/test/fixtures/runtime-config/.env b/test/fixtures/runtime-config/.env
index 3bff1d2f7d..c3004a6c6d 100644
--- a/test/fixtures/runtime-config/.env
+++ b/test/fixtures/runtime-config/.env
@@ -2,4 +2,7 @@ BASE_URL=/api
 PUBLIC_URL=https://google.com
 SERVER_BASE_URL
 API_SECRET=1234
+A=$B
+B=$C
+C=$A
 TOKEN=$2yr$10$tN3JmuvXZKGwi0l38A.SxUVemGrFJiyLunyqkOqOTE7LHsrSwMEmEB
diff --git a/test/fixtures/runtime-config/nuxt.config.js b/test/fixtures/runtime-config/nuxt.config.js
index 7bee052b0b..744ffda64c 100644
--- a/test/fixtures/runtime-config/nuxt.config.js
+++ b/test/fixtures/runtime-config/nuxt.config.js
@@ -6,7 +6,8 @@ export default {
   },
   privateRuntimeConfig: {
     baseURL: '${PUBLIC_URL}${BASE_URL}',
-    API_SECRET: ''
+    API_SECRET: '',
+    FOO: '123/${FOO}'
   },
   serverMiddleware: [
     (req, _, next) => {