feat: show proxy environment variables in npm config list

Adds proxy-related environment variables to npm config list output
to help users understand their proxy configuration. Variables are
checked case-insensitively to match the agent library behavior.

Closes #4170

Author: Max Black

lib/commands/config.js

@@ -4,7 +4,7 @@ const { spawn } = require('node:child_process')
 const { EOL } = require('node:os')
 const localeCompare = require('@isaacs/string-locale-compare')('en')
 const pkgJson = require('@npmcli/package-json')
-const { defaults, definitions, nerfDarts } = require('@npmcli/config/lib/definitions')
+const { defaults, definitions, nerfDarts, proxyEnv } = require('@npmcli/config/lib/definitions')
 const { log, output } = require('proc-log')
 const BaseCommand = require('../base-cmd.js')
 const { redact } = require('@npmcli/redact')
@@ -350,6 +350,23 @@ ${defData}
     }
 
     if (!long) {
+      const envVars = []
+
+      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])}`)
+        }
+      }
+
+      if (envVars.length > 0) {
+        msg.push('; environment-related config', '')
+        msg.push(...envVars)
+        msg.push('')
+      }
+
       msg.push(
         `; node bin location = ${process.execPath}`,
         `; node version = ${process.version}`,

tap-snapshots/test/lib/commands/config.js.test.cjs

@@ -23,6 +23,7 @@ exports[`test/lib/commands/config.js TAP config list --json > output matches sna
   "before": null,
   "bin-links": true,
   "browser": null,
+  "bypass-2fa": false,
   "ca": null,
   "cache-max": null,
   "cache-min": 0,
@@ -48,6 +49,7 @@ exports[`test/lib/commands/config.js TAP config list --json > output matches sna
   "engine-strict": false,
   "expect-result-count": null,
   "expect-results": null,
+  "expires": null,
   "fetch-retries": 2,
   "fetch-retry-factor": 10,
   "fetch-retry-maxtimeout": 60000,
@@ -97,6 +99,7 @@ exports[`test/lib/commands/config.js TAP config list --json > output matches sna
   "logs-dir": null,
   "logs-max": 10,
   "long": false,
+  "name": null,
   "maxsockets": 15,
   "message": "%s",
   "node-gyp": "{CWD}/node_modules/node-gyp/bin/node-gyp.js",
@@ -108,13 +111,15 @@ exports[`test/lib/commands/config.js TAP config list --json > output matches sna
   "omit": [],
   "omit-lockfile-registry-resolved": false,
   "only": null,
+  "orgs": null,
   "optional": null,
   "os": null,
   "otp": null,
   "package": [],
   "package-lock": true,
   "package-lock-only": false,
   "pack-destination": ".",
+  "packages": [],
   "parseable": false,
   "prefer-dedupe": false,
   "prefer-offline": false,
@@ -141,6 +146,11 @@ exports[`test/lib/commands/config.js TAP config list --json > output matches sna
   "sbom-format": null,
   "sbom-type": "library",
   "scope": "",
+  "scopes": null,
+  "packages-all": false,
+  "packages-and-scopes-permission": null,
+  "orgs-permission": null,
+  "token-description": null,
   "script-shell": null,
   "searchexclude": "",
   "searchlimit": 20,
@@ -187,6 +197,7 @@ auth-type = "web"
 before = null
 bin-links = true
 browser = null
+bypass-2fa = false
 ca = null
 ; cache = "{CACHE}" ; overridden by cli
 cache-max = null
@@ -214,6 +225,7 @@ editor = "{EDITOR}"
 engine-strict = false
 expect-result-count = null
 expect-results = null
+expires = null
 fetch-retries = 2
 fetch-retry-factor = 10
 fetch-retry-maxtimeout = 60000
@@ -266,6 +278,7 @@ logs-max = 10
 ; long = false ; overridden by cli
 maxsockets = 15
 message = "%s"
+name = null
 node-gyp = "{CWD}/node_modules/node-gyp/bin/node-gyp.js"
 node-options = null
 noproxy = [""]
@@ -275,13 +288,19 @@ omit = []
 omit-lockfile-registry-resolved = false
 only = null
 optional = null
+orgs = null
+orgs-permission = null
 os = null
 otp = null
 pack-destination = "."
 package = []
 package-lock = true
 package-lock-only = false
+packages = []
+packages-all = false
+packages-and-scopes-permission = null
 parseable = false
+password = (protected)
 prefer-dedupe = false
 prefer-offline = false
 prefer-online = false
@@ -307,6 +326,7 @@ save-prod = false
 sbom-format = null
 sbom-type = "library"
 scope = ""
+scopes = null
 script-shell = null
 searchexclude = ""
 searchlimit = 20
@@ -321,6 +341,7 @@ strict-ssl = true
 tag = "latest"
 tag-version-prefix = "v"
 timing = false
+token-description = null
 umask = 0
 unicode = false
 update-notifier = true

test/lib/commands/config.js

@@ -101,6 +101,49 @@ t.test('config list', async t => {
   t.matchSnapshot(output, 'output matches snapshot')
 })
 
+t.test('config list with proxy environment variables', async t => {
+  const originalHTTP = process.env.HTTP_PROXY
+  const originalHTTPS = process.env.HTTPS_PROXY
+  const originalNO = process.env.NO_PROXY
+
+  t.teardown(() => {
+    if (originalHTTP !== undefined) {
+      process.env.HTTP_PROXY = originalHTTP
+    } else {
+      delete process.env.HTTP_PROXY
+    }
+    if (originalHTTPS !== undefined) {
+      process.env.HTTPS_PROXY = originalHTTPS
+    } else {
+      delete process.env.HTTPS_PROXY
+    }
+    if (originalNO !== undefined) {
+      process.env.NO_PROXY = originalNO
+    } else {
+      delete process.env.NO_PROXY
+    }
+  })
+
+  process.env.HTTP_PROXY = 'http://proxy.example.com:8080'
+  process.env.HTTPS_PROXY = 'https://secure-proxy.example.com:8443'
+  process.env.NO_PROXY = 'localhost,127.0.0.1'
+
+  const { npm, joinedOutput } = await loadMockNpm(t, {
+    prefixDir: {
+      '.npmrc': 'test=value',
+    },
+  })
+
+  await npm.exec('config', ['list'])
+
+  const output = joinedOutput()
+
+  t.match(output, 'HTTP_PROXY = "http://proxy.example.com:8080"')
+  t.match(output, 'HTTPS_PROXY = "https://secure-proxy.example.com:8443"')
+  t.match(output, 'NO_PROXY = "localhost,127.0.0.1"')
+  t.match(output, 'environment-related config')
+})
+
 t.test('config list --long', async t => {
   const { npm, joinedOutput } = await loadMockNpm(t, {
     prefixDir: {