fix(envs): revert behavior of array in npm config (#194)

Reverts environment parsing of config arrays to use indexed names
instead of joining them with double newlines.  That change appears to
have been introduced when the enviromnent values were added back into
npm, but not in the same way they were done before.

Fixes: npm/cli#3775

---------

Co-authored-by: siemhesda <[email protected]>

lib/package-envs.js

@@ -1,32 +1,29 @@
-// https://github.com/npm/rfcs/pull/183
-
-const envVal = val => {
-  if (Array.isArray(val)) {
-    return val.map(v => envVal(v)).join('\n\n')
-  }
-  if (val === null || val === false) {
-    return ''
-  }
-  return String(val)
-}
-
-const packageEnvs = (env, vals, prefix) => {
+const packageEnvs = (vals, prefix, env = {}) => {
   for (const [key, val] of Object.entries(vals)) {
     if (val === undefined) {
       continue
-    } else if (val && !Array.isArray(val) && typeof val === 'object') {
-      packageEnvs(env, val, `${prefix}${key}_`)
+    } else if (val === null || val === false) {
+      env[`${prefix}${key}`] = ''
+    } else if (Array.isArray(val)) {
+      val.forEach((item, index) => {
+        packageEnvs({ [`${key}_${index}`]: item }, `${prefix}`, env)
+      })
+    } else if (typeof val === 'object') {
+      packageEnvs(val, `${prefix}${key}_`, env)
     } else {
-      env[`${prefix}${key}`] = envVal(val)
+      env[`${prefix}${key}`] = String(val)
     }
   }
   return env
 }
 
-module.exports = (env, pkg) => packageEnvs({ ...env }, {
-  name: pkg.name,
-  version: pkg.version,
-  config: pkg.config,
-  engines: pkg.engines,
-  bin: pkg.bin,
-}, 'npm_package_')
+// https://github.com/npm/rfcs/pull/183 defines which fields we put into the environment
+module.exports = pkg => {
+  return packageEnvs({
+    name: pkg.name,
+    version: pkg.version,
+    config: pkg.config,
+    engines: pkg.engines,
+    bin: pkg.bin,
+  }, 'npm_package_')
+}

lib/run-script-pkg.js

@@ -69,7 +69,7 @@ const runScriptPkg = async options => {
     path,
     scriptShell,
     binPaths,
-    env: packageEnvs(env, pkg),
+    env: { ...env, ...packageEnvs(pkg) },
     stdio,
     cmd,
     args,

test/make-spawn-args.js

@@ -39,7 +39,8 @@ t.test('spawn args', async t => {
           e.env.npm_package_config_test_null === '' &&
           e.env.npm_package_config_test_false === '' &&
           e.env.npm_package_config_test_string === pkg.config.test_string &&
-          e.env.npm_package_config_test_array === pkg.config.test_array.join('\n\n') &&
+          e.env.npm_package_config_test_array_0 === pkg.config.test_array[0] &&
+          e.env.npm_package_config_test_array_1 === pkg.config.test_array[1] &&
           e.env.npm_package_bin === pkg.bin &&
           e.env.npm_package_engines_npm === pkg.engines.npm &&
           e.env.npm_package_engines_node === pkg.engines.node &&