From 1a2538e42c5245aec759f467a33a1d915076d38d Mon Sep 17 00:00:00 2001
From: Vladimir Gorej <vladimir.gorej@gmail.com>
Date: Fri, 5 May 2017 18:01:08 +0200
Subject: [PATCH] feat: add renameKeys

Ref #27
---
 src/index.d.ts     |  9 +++++++++
 src/index.js       |  3 +++
 src/renameKeys.js  | 35 +++++++++++++++++++++++++++++++++++
 test/renameKeys.js | 23 +++++++++++++++++++++++
 4 files changed, 70 insertions(+)
 create mode 100644 src/renameKeys.js
 create mode 100644 test/renameKeys.js

diff --git a/src/index.d.ts b/src/index.d.ts
index c2b56ff91c..35361c6d2a 100644
--- a/src/index.d.ts
+++ b/src/index.d.ts
@@ -267,6 +267,15 @@ declare namespace RamdaAdjunct {
                 (either: Catamorphism<V1|V2>): T1|T2;
             }
         }
+
+        /**
+         * Creates a new object with the own properties of the provided object, but the
+         * keys renamed according to the keysMap object as `{oldKey: newKey}`.
+         * When some key is not found in the keysMap, then it's passed as-is.
+         */
+        renameKeys(keysMap: Object, obj: Object): Object
+        renameKeys(keysMap: Object): (obj: Object) => Object
+
     }
 
 }
diff --git a/src/index.js b/src/index.js
index 27b1244b5f..4ab9d1c430 100644
--- a/src/index.js
+++ b/src/index.js
@@ -48,6 +48,7 @@ import list from './list';
 import defaults from './defaults';
 import resetToDefault from './resetToDefault';
 import paths from './paths';
+import renameKeys from './renameKeys';
 
 // Type
 export { default as isNotUndefined } from './isNotUndefined';
@@ -99,6 +100,7 @@ export { default as list } from './list';
 export { default as defaults } from './defaults';
 export { default as resetToDefault } from './resetToDefault';
 export { default as paths } from './paths';
+export { default as renameKeys } from './renameKeys';
 
 /**
  * @namespace RA
@@ -154,6 +156,7 @@ const RA = {
   defaults,
   resetToDefault,
   paths,
+  renameKeys,
 };
 
 export default RA;
diff --git a/src/renameKeys.js b/src/renameKeys.js
new file mode 100644
index 0000000000..5062970199
--- /dev/null
+++ b/src/renameKeys.js
@@ -0,0 +1,35 @@
+import { curry, reduce, assoc, keys, has } from 'ramda';
+
+/**
+ * Creates a new object with the own properties of the provided object, but the
+ * keys renamed according to the keysMap object as `{oldKey: newKey}`.
+ * When some key is not found in the keysMap, then it's passed as-is.
+ *
+ * Keep in mind that in the case of keys conflict is behaviour undefined and
+ * the result may vary between various JS engines!
+ *
+ * @func renameKeys
+ * @memberOf RA
+ * @since {@link https://char0n.github.io/ramda-adjunct/1.5.0|v1.5.0}
+ * @category Object
+ * @sig {a: b} -> {a: *} -> {b: *}
+ * @param {!Object} keysMap
+ * @param {!Object} obj
+ * @return {!Object} New object with renamed keys
+ * @see {@link RA.renameKeysWith|renameKeysWith}
+ * @example
+ *
+ * const input = { firstName: 'Elisia', age: 22, type: 'human' };
+ *
+ * renameKeys({ firstName: 'name', type: 'kind', foo: 'bar' })(input);
+ * //=> { name: 'Elisia', age: 22, kind: 'human' }
+ */
+const renameKeys = curry((keysMap, obj) =>
+  reduce((accumulator, key) => {
+    const newKeyName = has(key, keysMap) ? keysMap[key] : key;
+
+    return assoc(newKeyName, obj[key], accumulator);
+  }, {}, keys(obj))
+);
+
+export default renameKeys;
diff --git a/test/renameKeys.js b/test/renameKeys.js
new file mode 100644
index 0000000000..d8f34cbe2d
--- /dev/null
+++ b/test/renameKeys.js
@@ -0,0 +1,23 @@
+import RA from '../src/index';
+import eq from './shared/eq';
+
+
+describe('renameKeys', function() {
+  it('tests renaming object keys', function() {
+    eq(RA.renameKeys({ key1: 'key2', key2: 'key3' }, { key1: 1, key2: 2 }), { key2: 1, key3: 2 });
+  });
+
+  it('tests renaming non existing keys', function() {
+    eq(RA.renameKeys({ nonExistingKey: 'key2' }, { key1: 1 }), { key1: 1 });
+  });
+
+  it('tests renaming keys on non object', function() {
+    eq(RA.renameKeys({ key1: 'key2' }, null), {});
+    eq(RA.renameKeys({ key1: 'key2' }, undefined), {});
+  });
+
+  it('tests currying', function() {
+    eq(RA.renameKeys({ key1: 'key2', key2: 'key3' }, { key1: 1, key2: 2 }), { key2: 1, key3: 2 });
+    eq(RA.renameKeys({ key1: 'key2', key2: 'key3' })({ key1: 1, key2: 2 }), { key2: 1, key3: 2 });
+  });
+});