#411 Comparison of currency values

docs/04-api.md

@@ -70,6 +70,52 @@ Divides the current currency instance by `number`.
 currency(123.45).divide(2); // => "61.73"
 ```
 
+### lessThan
+
+`currency.lessThan( number|currency )`
+
+Compares if value is less than another currency instance's value
+
+```js
+currency(10).lessThan(currency('10.1')); // => true
+currency('10').lessThan(10.01); // => true
+```
+
+### lessThanOrEqual
+
+`currency.lessThanOrEqual( number|currency )`
+
+Compares if value is less than or equal to another currency instance's value
+
+```js
+currency(10).lessThanOrEqual(currency('10.1')); // => true
+currency('10').lessThanOrEqual(10.01); // => true
+currency('10').lessThanOrEqual(10); // => true
+```
+
+### greaterThan
+
+`currency.greaterThan( number|currency )`
+
+Compares if value is greater than another currency instance's value
+
+```js
+currency(10).greaterThan(currency('9.99')); // => true
+currency('10').greaterThan(9.99); // => true
+```
+
+### greaterThanOrEqual
+
+`currency.greaterThanOrEqual( number|currency )`
+
+Compares if value is greater than or equal to another currency instance's value
+
+```js
+currency(10).greaterThanOrEqual(currency('9.99')); // => true
+currency('10').greaterThanOrEqual(9.99); // => true
+currency('9.99').greaterThanOrEqual(9.99); // => true
+```
+
 ### distribute
 
 `currency.distribute( number )`

src/currency.js

@@ -146,6 +146,66 @@ currency.prototype = {
     return currency(intValue /= parse(number, _settings, false), _settings);
   },
 
+  /**
+   * Compares if value is less than another currency instance's value
+   * @param {number|currency} foreign 
+   * @returns {boolean}
+   */
+  lessThan(foreign) {
+    let { value } = this;
+    if (foreign instanceof currency) {
+      let { value: foreignValue } = foreign;
+
+      return value < foreignValue;
+    }
+    return value < foreign;
+  },
+
+  /**
+   * Compares if value is less than or equal to another currency instance's value
+   * @param {number|currency} foreign 
+   * @returns {boolean}
+   */
+  lessThanOrEqual(foreign) {
+    let { value } = this;
+    if (foreign instanceof currency) {
+      let { value: foreignValue } = foreign;
+
+      return value <= foreignValue;
+    }
+    return value < foreign;
+  },
+
+  /**
+   * Compares if value is greater than another currency instance's value
+   * @param {number|currency} foreign 
+   * @returns {boolean}
+   */
+  greaterThan(foreign) {
+    let { value } = this;
+    if (foreign instanceof currency) {
+      let { value: foreignValue } = foreign;
+
+      return value >= foreignValue;
+    }
+    return value >= foreign;
+  },
+
+  /**
+   * Compares if value is greater than or equal to another currency instance's value
+   * @param {number|currency} foreign 
+   * @returns {boolean}
+   */
+  greaterThanOrEqual(foreign) {
+    let { value } = this;
+    if (foreign instanceof currency) {
+      let { value: foreignValue } = foreign;
+
+      return value >= foreignValue;
+    }
+    return value >= foreign;
+  },
+
   /**
    * Takes the currency amount and distributes the values evenly. Any extra pennies
    * left over from the distribution will be stacked onto the first set of entries.

test/test.js

@@ -555,4 +555,51 @@ test('should handle fractional cents', t => {
   var values = currency(1234.56, { fromCents: true });
   t.is(values.intValue, 1235);
   t.is(values.value, 12.35);
-});
+});
+
+test('lessThan', t => {
+  let c1 = currency('10');
+  let c2 = currency(10);
+
+  t.is(c1.lessThan(currency('10.1')), true);
+  t.is(c1.lessThan(10.01), true);
+  t.is(c2.lessThan(currency('10.1')), true);
+  t.is(c2.lessThan(10.01), true);
+});
+
+test('lessThanOrEqual', t => {
+  let c1 = currency('10');
+  let c2 = currency(10);
+
+  t.is(c1.lessThanOrEqual(currency('10')), true);
+  t.is(c1.lessThanOrEqual(10.01), true);
+  t.is(c1.lessThanOrEqual('10.01'), true);
+
+  t.is(c2.lessThanOrEqual(currency('10')), true);
+  t.is(c2.lessThanOrEqual(10.01), true);
+  t.is(c2.lessThanOrEqual('10.01'), true);
+});
+
+test('greaterThan', t => {
+  let c1 = currency('10');
+  let c2 = currency(10);
+
+  t.is(c1.greaterThan(currency('9.99')), true);
+  t.is(c1.greaterThan(9.99), true);
+
+  t.is(c2.greaterThan(currency('9.99')), true);
+  t.is(c2.greaterThan(9.99), true);
+});
+
+test('greaterThanOrEqual', t => {
+  let c1 = currency('10');
+  let c2 = currency(10);
+
+  t.is(c1.greaterThanOrEqual(currency('10')), true);
+  t.is(c1.greaterThanOrEqual(9.99), true);
+  t.is(c1.greaterThanOrEqual('9.99'), true);
+
+  t.is(c2.greaterThanOrEqual(currency('10')), true);
+  t.is(c2.greaterThanOrEqual(9.99), true);
+  t.is(c2.greaterThanOrEqual('9.99'), true);
+});