fix: check proxy env vars case-insensitively to match agent behavior

The agent library (via proxy.js) checks proxy environment variables
case-insensitively by converting all env var names to lowercase before
checking. This updates npm config list to do the same, ensuring that
variables like Http_Proxy, HTTP_PROXY, and http_proxy are all detected.

- Updated proxyEnv list to use lowercase keys matching agent library
- Modified config list to check environment variables case-insensitively
- Now finds any casing of http_proxy, https_proxy, proxy, and no_proxy

Author: Max Black

lib/commands/config.js

@@ -353,9 +353,14 @@ ${defData}
       const envVars = []
 
       // Show proxy-related environment variables if they're set
-      for (const envVar of proxyEnv) {
-        if (process.env[envVar]) {
-          envVars.push(`; ${envVar} = ${JSON.stringify(process.env[envVar])}`)
+      // Check case-insensitively since environment variables can be set in any casing
+      // and the agent library (via proxy.js) checks them case-insensitively
+      const foundEnvVars = new Set()
+      for (const key of Object.keys(process.env)) {
+        const lowerKey = key.toLowerCase()
+        if (proxyEnv.includes(lowerKey) && !foundEnvVars.has(lowerKey)) {
+          foundEnvVars.add(lowerKey)
+          envVars.push(`; ${key} = ${JSON.stringify(process.env[key])}`)
         }
       }
 

workspaces/config/lib/definitions/index.js

@@ -73,12 +73,11 @@ const nerfDarts = [
 
 // Environment variables that can affect npm's behavior but are not npm configs
 // These are shown in `npm config list` to help users understand their environment
+// This list matches the keys checked in @npmcli/agent's proxy detection
 const proxyEnv = [
-  'HTTP_PROXY',
-  'HTTPS_PROXY',
-  'NO_PROXY',
   'http_proxy',
   'https_proxy',
+  'proxy',
   'no_proxy',
 ]