Merge pull request #74 from herecydev/master

Added merge multiple that outputs an array

README.md

@@ -312,6 +312,43 @@ merge.smart({
 }
 ```
 
+## Multiple Merging
+
+### **`merge.multiple(...configuration | [...configuration])`**
+
+Sometimes you may need to support multiple targets, *webpack-merge* will accept an object where each key represents the target configuration. The output becomes an *array* of configurations where matching keys are merged and non-matching keys are added.
+
+```javascript
+var path = require('path');
+var baseConfig = {
+    server: {
+      target: 'node',
+      output: {
+        path: path.resolve(__dirname, 'dist'),
+        filename: 'lib.node.js'
+      }
+    },
+    client: {
+      output: {
+        path: path.resolve(__dirname, 'dist'),
+        filename: 'lib.js'
+      }
+    }
+  };
+
+// specialized configuration
+var production = {
+    client: {
+      output: {
+        path: path.resolve(__dirname, 'dist'),
+        filename: '[name].[hash].js'
+      }
+    }
+  }
+
+module.exports = merge.multiple(baseConfig, production)
+```
+
 > Check out [SurviveJS - Webpack and React](http://survivejs.com/) to dig deeper into the topic.
 
 ## Development

src/index.js

@@ -1,5 +1,5 @@
 import {
-  differenceWith, mergeWith, unionWith
+  differenceWith, mergeWith, unionWith, values
 } from 'lodash';
 import joinArrays from './join-arrays';
 import { uniteRules } from './join-arrays-smart';
@@ -41,6 +41,8 @@ const mergeSmart = merge({
   }
 });
 
+const mergeMultiple = (...sources) => values(merge(sources));
+
 // rules: { <field>: <'append'|'prepend'|'replace'> }
 // All default to append but you can override here
 const mergeStrategy = (rules = {}) => merge({
@@ -103,6 +105,7 @@ function isRule(key) {
 }
 
 module.exports = merge;
+module.exports.multiple = mergeMultiple;
 module.exports.smart = mergeSmart;
 module.exports.strategy = mergeStrategy;
 module.exports.smartStrategy = mergeSmartStrategy;

tests/merge-multiple-tests.js

@@ -0,0 +1,169 @@
+/* eslint-env mocha */
+const assert = require('assert');
+
+function multipleTests(merge) {
+  it('should override objects', function () {
+    const a = {
+      client: {
+        entry: './client.js'
+      }
+    };
+    const b = {
+      client: {
+        entry: './replaced.js'
+      }
+    };
+    const result = [
+      {
+        entry: './replaced.js'
+      }
+    ];
+
+    assert.deepEqual(merge(a, b), result);
+  });
+
+  it('should add new objects if not existing', function () {
+    const a = {
+      client: {
+        entry: './client.js'
+      },
+      server: {
+        entry: './server.js'
+      }
+    };
+    const b = {
+      client: {
+        entry: './replaced.js'
+      }
+    };
+    const result = [
+      {
+        entry: './replaced.js'
+      },
+      {
+        entry: './server.js'
+      }
+    ];
+
+    assert.deepEqual(merge(a, b), result);
+  });
+
+  it('should add different configurations without merging', function () {
+    const a = {
+      client: {
+        entry: './client.js'
+      }
+    };
+    const b = {
+      server: {
+        entry: './server.js'
+      }
+    };
+    const result = [
+      {
+        entry: './client.js'
+      },
+      {
+        entry: './server.js'
+      }
+    ];
+
+    assert.deepEqual(merge(a, b), result);
+  });
+
+  it('should work with an array of objects', function () {
+    const a = {
+      client: {
+        entry: ['./client.js', './client2.js']
+      },
+      server: {
+        entry: ['./server.js', './server2.js']
+      }
+    };
+    const b = {
+      client: {
+        entry: ['./replaced.js', './replaced2.js']
+      }
+    };
+    const result = [
+      {
+        entry: ['./client.js', './client2.js', './replaced.js', './replaced2.js']
+      },
+      {
+        entry: ['./server.js', './server2.js']
+      }
+    ];
+
+    assert.deepEqual(merge(a, b), result);
+  });
+
+  it('should deeply merge objects', function () {
+    const a = {
+      client: {
+        entry: {
+          main: './client.js'
+        }
+      },
+      server: {
+        entry: {
+          main: './server.js'
+        }
+      }
+    };
+    const b = {
+      client: {
+        entry: {
+          main: './replaced.js'
+        }
+      }
+    };
+    const result = [
+      {
+        entry: {
+          main: './replaced.js'
+        }
+      },
+      {
+        entry: {
+          main: './server.js'
+        }
+      }
+    ];
+
+    assert.deepEqual(merge(a, b), result);
+  });
+
+  it('should merge where keys exist and add where not', function () {
+    const a = {
+      client: {
+        entry: './client.js'
+      },
+      server: {
+        entry: './server.js'
+      }
+    };
+    const b = {
+      server: {
+        entry: './replaced.js'
+      },
+      test: {
+        entry: './test.js'
+      }
+    };
+    const result = [
+      {
+        entry: './client.js'
+      },
+      {
+        entry: './replaced.js'
+      },
+      {
+        entry: './test.js'
+      }
+    ];
+
+    assert.deepEqual(merge(a, b), result);
+  });
+}
+
+module.exports = multipleTests;

tests/test-merge-multiple.js

@@ -0,0 +1,9 @@
+/* eslint-env mocha */
+const webpackMerge = require('..');
+const mergeMultipleTests = require('./merge-multiple-tests');
+
+describe('Multiple merge', function () {
+  const merge = webpackMerge.multiple;
+
+  mergeMultipleTests(merge);
+});