Make strict mode as a configurable option ( using env variable )

In strict mode, Only versions available in the cache will appear in the info response.

README.md

@@ -1,4 +1,3 @@
-# npm-offline-registry
 Supper simple NPM registry server for offline NPM install
 
 # Usage
@@ -56,3 +55,14 @@ Please check config.js. All config values can be over-written by `environment-va
 If you set the ``ENABLE_NPM_FAILOVER`` config value to ``false`` then npm-offlin-registry will not attempt to
 contact the upstream NPM registry for unknown packages and instead return a 404 response, meaning you can use
 it as an alternative to the NPM registry behind a firewall / isolated from the internet.
+
+# Enabling strict mode
+
+If config value `STRICT` is set to true, while npm checks for the available versions of a given packages, 
+registry server will reply with list of cached versions.
+In this case, if the version is not previously cached, npm-offline-install will fail with, error message `version not available`
+
+example
+```bash 
+env STRICT=true npm-offline-registry`
+```

config.js

@@ -3,7 +3,8 @@ var defaultConfig = {
   NPM_PATH       : process.env.HOME + '/.npm',
   REGISTRY_NAME  : 'registry.npmjs.org',
   PORT: 8234,
-  ENABLE_NPM_FAILOVER: true
+  ENABLE_NPM_FAILOVER: true,
+  STRICT: false
 };
 
 var config = {};
@@ -21,5 +22,8 @@ if( config.ENABLE_NPM_FAILOVER == 'false' ){
   config.ENABLE_NPM_FAILOVER = false;
 }
 
+if( config.STRICT == 'true' ){
+  config.STRICT = true;
+}
 module.exports = config;
 

package.json

@@ -1,6 +1,6 @@
 {
   "name": "npm-offline-registry",
-  "version": "0.0.7",
+  "version": "0.0.8",
   "description": "Super simple loca npm registry server for offline usage",
   "main": "bin/www",
   "directories": {

utils.js

@@ -29,17 +29,26 @@ exports.readFile = readFile;
 
 exports.patchData = function ( data ){
   /* Get the list of versions which is available in local cache */
-  var cachedVersions = fs.readdirSync( path.join( NPM_PATH, data.name ) );
+  var cacheJsonFile, cacheJsonFileData = [];
+
+  if( config.STRICT ){
+      cacheJsonFile = path.join( NPM_PATH, data.name );
+      cacheJsonFileData = fs.existsSync( cacheJsonFile ) ? fs.readdirSync( cacheJsonFile ) : [];
+  }
+
   Object.keys(data.versions).forEach( function( v ){
     var val = data.versions[v];
 
-    /* Suppose our cache.json is at latest revision. It contains lot of versions which is not available in local cache.
-    Then, Remove the versions which is not in local cache from the list. Otherwise npm will always choose higher versions whcih is not available in our cache */
-    /* TODO: If this feature causing problem, We can make this behaviour optional via some commandline-arguments/Env-variables */
-    if( cachedVersions.indexOf(v) == -1 ){
-      delete data.versions[v];
-      return;
+
+    if( cacheJsonFileData.length && config.STRICT ){
+      /* Suppose our cache.json is at latest revision. It contains lot of versions which is not available in local cache.
+      Then, Remove the versions which is not in local cache from the list. Otherwise npm will always choose higher versions whcih is not available in our cache */
+      if( cacheJsonFileData.indexOf(v) == -1 ){
+        delete data.versions[v];
+        return;
+      }
     }
+
     var protocal = 'http://';
     if( val.dist.tarball.indexOf( 'https:' ) !== false ){
       protocal = 'https://';