.

.babelrc

@@ -0,0 +1,4 @@
+{
+  "presets": [ "es2015" ]
+}
+

.gitignore

@@ -31,3 +31,4 @@ node_modules
 
 # Optional REPL history
 .node_repl_history
+lib

.npmignore

@@ -0,0 +1,2 @@
+src
+test

package.json

@@ -0,0 +1,34 @@
+{
+  "name": "ht-utils",
+  "version": "1.0.0",
+  "description": "Hudson-Taylor utils",
+  "main": "lib/index.js",
+  "scripts": {
+    "test": "semistandard && mocha -R spec -r babel-register --bail",
+    "build": "babel src -d lib",
+    "prepublish": "npm run build"
+  },
+  "repository": {
+    "type": "git",
+    "url": "git+https://github.com/hudson-taylor/utils.git"
+  },
+  "keywords": [
+    "hudson-taylor"
+  ],
+  "author": "Adam Brady <[email protected]>",
+  "license": "ISC",
+  "bugs": {
+    "url": "https://github.com/hudson-taylor/utils/issues"
+  },
+  "homepage": "https://github.com/hudson-taylor/utils#readme",
+  "devDependencies": {
+    "babel-cli": "^6.5.1",
+    "babel-preset-es2015": "^6.5.0",
+    "babel-register": "^6.5.2",
+    "mocha": "^2.4.5",
+    "semistandard": "^7.0.5"
+  },
+  "dependencies": {
+    "async": "^1.5.2"
+  }
+}

src/index.js

@@ -0,0 +1,72 @@
+import async from 'async';
+
+export function merge () {
+  // Merge objects passed as arguments, left to right precidence.
+
+  let result = {};
+
+  for (let i = 0; i < arguments.length; i++) {
+    let keys = Object.keys(arguments[i]);
+    for (let k = 0; k < keys.length; k++) {
+      let key = keys[k];
+      if (!result.hasOwnProperty(key)) {
+        result[key] = arguments[i][key];
+      }
+    }
+  }
+
+  return result;
+}
+
+export function formatError (err) {
+  if (err.error) return err;
+  if (err instanceof Error) {
+    err = err.message || err.toString();
+  }
+  return { error: err };
+}
+
+export function getLastResult (methods, callback, isService) {
+  async.reduce(methods, undefined, (lastResult, stored, done) => {
+    let {
+      service,
+      method,
+      data = lastResult
+    } = stored;
+
+    let call = [
+      service,
+      method,
+      data,
+      function (err, result) {
+        if (err) {
+          let r = {
+            error: err,
+            method
+          };
+          if (!isService) {
+            r.service = service;
+          }
+          return done(r);
+        }
+
+        if (!isService) {
+          var index = methods.indexOf(stored);
+          var next = methods[index + 1];
+
+          if (next && next.data && !next.data[0].data) {
+            methods[index + 1].data[0].data = result;
+          }
+        }
+
+        return done(null, result);
+      }
+    ];
+
+    if (isService) {
+      call.shift();
+    }
+
+    this.call(...call);
+  }, callback);
+}

test/index.js

@@ -0,0 +1,65 @@
+/* global describe, it */
+import assert from 'assert';
+
+import {
+  merge,
+  formatError
+} from '../src';
+
+describe('Utilities', function () {
+  describe('merge', function () {
+    it('should merge', function () {
+      let data1 = { a: 5 };
+      let data2 = { a: 15, b: 10 };
+
+      let result = merge(data1, data2);
+
+      assert.deepEqual(result, {
+        a: data1.a,
+        b: data2.b
+      });
+    });
+  });
+
+  describe('formatError', function () {
+    it('should return object', function () {
+      let str = 'err1234';
+
+      let data = formatError(str);
+
+      assert.deepEqual(data, {
+        error: str
+      });
+    });
+
+    it('should convert Error instance to object', function () {
+      let str = 'err1234';
+
+      let err = new Error(str);
+
+      let data = formatError(err);
+
+      assert.deepEqual(data, {
+        error: str
+      });
+
+      let err2 = new Error();
+
+      let data2 = formatError(err2);
+
+      assert.deepEqual(data2, {
+        error: 'Error'
+      });
+    });
+
+    it('should not do anything if data has an error variable', function () {
+      let _data = {
+        error: 'something'
+      };
+
+      let data = formatError(_data);
+
+      assert.deepEqual(data, _data);
+    });
+  });
+});