validate-args: Consume warnings from new npm-install-checks

PR-URL: npm#11212
Credit: @iarna
Reviewed-By: @othiym23

lib/install/validate-args.js

@@ -3,6 +3,7 @@ var validate = require('aproba')
 var asyncMap = require('slide').asyncMap
 var chain = require('slide').chain
 var npmInstallChecks = require('npm-install-checks')
+var iferr = require('iferr')
 var checkEngine = npmInstallChecks.checkEngine
 var checkPlatform = npmInstallChecks.checkPlatform
 var npm = require('../npm.js')
@@ -19,14 +20,21 @@ module.exports = function (idealTree, args, next) {
   }, next)
 }
 
+function getWarnings (pkg) {
+  while (pkg.parent) pkg = pkg.parent
+  if (!pkg.warnings) pkg.warnings = []
+  return pkg.warnings
+}
+
 var isInstallable = module.exports.isInstallable = function (pkg, next) {
   var force = npm.config.get('force')
   var nodeVersion = npm.config.get('node-version')
   var strict = npm.config.get('engine-strict')
-  chain([
-    [checkEngine, pkg, npm.version, nodeVersion, force, strict],
-    [checkPlatform, pkg, force]
-  ], next)
+  checkEngine(pkg, npm.version, nodeVersion, force, strict, iferr(next, thenWarnEngineIssues))
+  function thenWarnEngineIssues (warn) {
+    if (warn) getWarnings(pkg).push(warn)
+    checkPlatform(pkg, force, next)
+  }
 }
 
 function checkSelf (idealTree, pkg, force, next) {