fix(@schematics/update): use rc to find and read npm config

Author: clydin

package.json

@@ -132,6 +132,7 @@
     "postcss-url": "^7.3.2",
     "protractor": "^5.3.1",
     "raw-loader": "^0.5.1",
+    "rc": "^1.2.8",
     "rxjs": "^6.0.0",
     "sass-loader": "^7.0.2",
     "semver": "^5.3.0",

packages/schematics/update/package.json

@@ -18,6 +18,7 @@
     "npm-registry-client": "^8.5.1",
     "semver": "^5.3.0",
     "semver-intersect": "^1.1.2",
+    "rc": "^1.2.8",
     "rxjs": "^6.0.0"
   }
 }

packages/schematics/update/update/npm.ts

@@ -6,18 +6,21 @@
  * found in the LICENSE file at https://angular.io/license
  */
 import { logging } from '@angular-devkit/core';
-import { exec } from 'child_process';
 import { readFileSync } from 'fs';
 import { Observable, ReplaySubject, concat, of } from 'rxjs';
 import { concatMap, defaultIfEmpty, filter, first, map, toArray } from 'rxjs/operators';
 import * as url from 'url';
 import { NpmRepositoryPackageJson } from './npm-package-json';
 
 const RegistryClient = require('npm-registry-client');
+const rc = require('rc');
 
 const npmPackageJsonCache = new Map<string, Observable<NpmRepositoryPackageJson>>();
 const npmConfigOptionCache = new Map<string, Observable<string | undefined>>();
 
+
+const npmConfig = rc('npm', {}, {});
+
 function getNpmConfigOption(
   option: string,
   scope?: string,
@@ -43,26 +46,15 @@ function getNpmConfigOption(
 
   const subject = new ReplaySubject<string | undefined>(1);
 
-  try {
-    exec(`npm get ${fullOption}`, (error, data) => {
-      if (error) {
-        subject.next();
-      } else {
-        data = data.trim();
-        if (!data || data === 'undefined' || data === 'null') {
-          subject.next();
-        } else {
-          subject.next(data);
-        }
-      }
-
-      subject.complete();
-    });
-  } catch {
+  const optionValue = npmConfig && npmConfig[fullOption];
+  if (optionValue == undefined || optionValue == null) {
     subject.next();
-    subject.complete();
+  } else {
+    subject.next(optionValue);
   }
 
+  subject.complete();
+
   value = subject.asObservable();
   npmConfigOptionCache.set(fullOption, value);