test showing failure of recursive expansion

CHANGELOG.md

@@ -2,7 +2,13 @@
 
 All notable changes to this project will be documented in this file. See [standard-version](https://github.com/conventional-changelog/standard-version) for commit guidelines.
 
-## [Unreleased](https://github.com/motdotla/dotenv-expand/compare/v11.0.3...master)
+## [Unreleased](https://github.com/motdotla/dotenv-expand/compare/v11.0.4...master)
+
+## [11.0.4](https://github.com/motdotla/dotenv-expand/compare/v11.0.3...v11.0.4) (2024-02-15)
+
+### Changed
+
+- 🐞 fix recursive expansion when expansion keys in reverse order ([#118](https://github.com/motdotla/dotenv-expand/pull/118))
 
 ## [11.0.3](https://github.com/motdotla/dotenv-expand/compare/v11.0.2...v11.0.3) (2024-02-11)
 

lib/main.js

@@ -26,7 +26,12 @@ function interpolate (value, processEnv, parsed) {
       }
 
       if (parsed[key]) {
-        return parsed[key]
+        // avoid recursion from EXPAND_SELF=$EXPAND_SELF
+        if (parsed[key] === value) {
+          return parsed[key]
+        } else {
+          return interpolate(parsed[key], processEnv, parsed)
+        }
       }
 
       if (defaultValue) {

tests/main.js

@@ -34,6 +34,19 @@ t.test('expands environment variables', ct => {
   ct.end()
 })
 
+t.test('expands self without a recursive call stack error', ct => {
+  const dotenv = {
+    parsed: {
+      EXPAND_SELF: '$EXPAND_SELF'
+    }
+  }
+  const parsed = dotenvExpand.expand(dotenv).parsed
+
+  ct.equal(parsed.EXPAND_SELF, '$EXPAND_SELF') // because it ends up accessing parsed[key].
+
+  ct.end()
+})
+
 t.test('uses environment variables existing already on the machine for expansion', ct => {
   process.env.MACHINE = 'machine'
   const dotenv = {
@@ -163,7 +176,7 @@ t.test('handle mixed values', ct => {
   ct.end()
 })
 
-t.test('expands environment variables', ct => {
+t.test('expands environment variables (process.env)', ct => {
   const dotenv = require('dotenv').config({ path: 'tests/.env.test', processEnv: {} })
   dotenvExpand.expand(dotenv)
 
@@ -467,7 +480,7 @@ t.test('does not choke', ct => {
   ct.end()
 })
 
-t.test('expands self without a recursive call stack error', ct => {
+t.test('expands self without a recursive call stack error (process.env)', ct => {
   const dotenv = require('dotenv').config({ path: 'tests/.env.test', processEnv: {} })
   const parsed = dotenvExpand.expand(dotenv).parsed
 
@@ -509,3 +522,37 @@ t.test('does not expand dollar sign that are not variables', ct => {
 
   ct.end()
 })
+
+t.test('expands recursively', ct => {
+  const dotenv = {
+    parsed: {
+      MOCK_SERVER_PORT: '8090',
+      MOCK_SERVER_HOST: 'http://localhost:${MOCK_SERVER_PORT}',
+      BACKEND_API_HEALTH_CHECK_URL: '${MOCK_SERVER_HOST}/ci-health-check'
+    }
+  }
+  const parsed = dotenvExpand.expand(dotenv).parsed
+
+  ct.equal(parsed.MOCK_SERVER_PORT, '8090')
+  ct.equal(parsed.MOCK_SERVER_HOST, 'http://localhost:8090')
+  ct.equal(parsed.BACKEND_API_HEALTH_CHECK_URL, 'http://localhost:8090/ci-health-check')
+
+  ct.end()
+})
+
+t.test('expands recursively reverse order', ct => {
+  const dotenv = {
+    parsed: {
+      BACKEND_API_HEALTH_CHECK_URL: '${MOCK_SERVER_HOST}/ci-health-check',
+      MOCK_SERVER_HOST: 'http://localhost:${MOCK_SERVER_PORT}',
+      MOCK_SERVER_PORT: '8090'
+    }
+  }
+  const parsed = dotenvExpand.expand(dotenv).parsed
+
+  ct.equal(parsed.MOCK_SERVER_PORT, '8090')
+  ct.equal(parsed.MOCK_SERVER_HOST, 'http://localhost:8090')
+  ct.equal(parsed.BACKEND_API_HEALTH_CHECK_URL, 'http://localhost:8090/ci-health-check')
+
+  ct.end()
+})