Remove duplicate libvips version/platform check

lib/constructor.js

@@ -4,42 +4,10 @@ const path = require('path');
 const util = require('util');
 const stream = require('stream');
 const events = require('events');
-const semver = require('semver');
 const is = require('./is');
-const platform = require('./platform');
-const sharp = require('../build/Release/sharp.node');
 
-// Vendor platform
-(function () {
-  let vendorPlatformId;
-  try {
-    vendorPlatformId = require('../vendor/platform.json');
-  } catch (err) {
-    return;
-  }
-  const currentPlatformId = platform();
-  /* istanbul ignore if */
-  if (currentPlatformId !== vendorPlatformId) {
-    throw new Error(`'${vendorPlatformId}' binaries cannot be used on the '${currentPlatformId}' platform. Please remove the 'node_modules/sharp/vendor' directory and run 'npm rebuild'.`);
-  }
-})();
-
-// Versioning
-let versions = {
-  vips: sharp.libvipsVersion()
-};
-(function () {
-  // Does libvips meet minimum requirement?
-  const libvipsVersionMin = require('../package.json').config.libvips;
-  /* istanbul ignore if */
-  if (semver.lt(versions.vips, libvipsVersionMin)) {
-    throw new Error('Found libvips ' + versions.vips + ' but require at least ' + libvipsVersionMin);
-  }
-  // Include versions of dependencies, if present
-  try {
-    versions = require('../vendor/versions.json');
-  } catch (err) {}
-})();
+require('./libvips').hasVendoredLibvips();
+const sharp = require('../build/Release/sharp.node');
 
 // Use NODE_DEBUG=sharp to enable libvips warnings
 const debuglog = util.debuglog('sharp');
@@ -251,7 +219,12 @@ Sharp.format = sharp.format();
  * @example
  * console.log(sharp.versions);
  */
-Sharp.versions = versions;
+Sharp.versions = {
+  vips: sharp.libvipsVersion()
+};
+try {
+  Sharp.versions = require('../vendor/versions.json');
+} catch (err) {}
 
 /**
  * Export constructor.