Merge pull request #17 from christav/after-the-fact-customizer

After the fact customization

README.md

@@ -108,11 +108,23 @@ c3.configure('test', function (c) {
   c.useSql('testmachine', 'testdb');
 });
 
+c3.configure('production', function (c) {
+  c.useSql('realDatabase', 'actualDb');
+});
+
+// Can also customize after creation, customizations
+// will affect any child configs too!
+c3 = envconf.createConfig();
+var prod = c3('prod');
+
+c3.customize(addConfigHelpers);
+
 c3.configure('production', function (c) {
   c.useSql('realDatabase', 'actualDb');
 });
 ```
 
+
 ## Saving and Restoring config values
 
 Are you making changes to a global configuration in your unit tests, and want

lib/index.js

@@ -29,9 +29,10 @@ function Snapshot(settings, environments) {
   });
 }
 
-function Config(parent, defaultEnvVar, customizer) {
+function Config(parent, defaultEnvVar, initialCustomizer) {
   var environments = { };
   var settings = { };
+  var customizer = initialCustomizer;
 
   if (!defaultEnvVar) {
     defaultEnvVar = 'NODE_ENV';
@@ -55,6 +56,26 @@ function Config(parent, defaultEnvVar, customizer) {
     }
   };
 
+  config.customize = function (newCustomizer) {
+    newCustomizer(this);
+    if (!customizer) {
+      customizer = newCustomizer;
+    } else {
+      customizer = (function (oldCustomizer) {
+        return function (c) {
+          oldCustomizer(c);
+          newCustomizer(c);
+        };
+      }(customizer));
+    }
+
+    Object.keys(environments).forEach(function (envName) {
+      environments[envName].customize(newCustomizer);
+    });
+
+    return this;
+  };
+
   config.set = function (setting, value) {
     if (arguments.length === 2) {
       settings[setting] = function () { return value; };

test/config-test.js

@@ -269,6 +269,10 @@ describe('Config customization', function () {
     config.customValue = ++count;
   }
 
+  function afterCreateCustomizer(config) {
+    config.wasCustomizedAfterCreation = true;
+  }
+
   var spy;
 
   beforeEach(function () {
@@ -306,6 +310,39 @@ describe('Config customization', function () {
 
     spy.callCount.should.equal(2);
   });
+
+  it('should customize after creation', function () {
+    var c = envconf.createConfig();
+    c.customize(afterCreateCustomizer);
+
+    c.wasCustomizedAfterCreation.should.be.true;
+  });
+
+  it('should customize existing child environments', function () {
+    var c = envconf.createConfig();
+    var dev = c('dev');
+    var localdev = dev('local');
+
+    c.customize(afterCreateCustomizer);
+
+    dev.wasCustomizedAfterCreation.should.be.true;
+    localdev.wasCustomizedAfterCreation.should.be.true;
+  });
+
+  it('should customize new child environments after customizing', function () {
+    var c = envconf.createConfig();
+    c.customize(afterCreateCustomizer);
+
+    c('dev').wasCustomizedAfterCreation.should.be.true;
+  });
+
+  it('should add customizers instead of replacing', function () {
+    var c = envconf.createConfig({customizer: spy});
+    c.customize(afterCreateCustomizer);
+
+    c('dev').customValue.should.equal(2);
+    c('dev').wasCustomizedAfterCreation.should.be.true;
+  });
 });
 
 describe('Snapshot and restore', function () {