Isogram solution

Author: eprunier

isogram/README.md

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+# Isogram
+
+Determine if a word or phrase is an isogram.
+
+An isogram (also known as a "nonpattern word") is a word or phrase without a repeating letter.
+
+Examples of isograms:
+
+- lumberjacks
+- background
+- downstream
+
+The word *isograms*, however, is not an isogram, because the s repeats.
+
+## Setup
+
+Go through the setup instructions for JavaScript to
+install the necessary dependencies:
+
+http://exercism.io/languages/javascript
+
+## Making the Test Suite Pass
+
+Execute the tests with:
+
+    jasmine-node .
+
+In many test suites all but the first test have been skipped.
+
+Once you get a test passing, you can unskip the next one by
+changing `xit` to `it`.
+
+## Source
+
+Wikipedia [https://en.wikipedia.org/wiki/Isogram](https://en.wikipedia.org/wiki/Isogram)
+
+## Submitting Incomplete Problems
+It's possible to submit an incomplete solution so you can see how others have completed the exercise.
+

isogram/isogram.js

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+const Isogram = function (input) {
+	this.value = input.toLowerCase();
+};
+
+const notRemovable = /[-\s]/;
+
+Isogram.prototype.isIsogram = function () {
+	const chars = Array
+		.from(this.value)
+		.reduce((acc, char) => {
+			if (acc.indexOf(char) === -1 || notRemovable.test(char)) {
+				return acc + char;
+			} else {
+				return acc
+			}
+		});
+
+	return chars === this.value;
+};
+
+module.exports = Isogram;

isogram/isogram.spec.js

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+var Isogram = require('./isogram');
+
+describe('Isogram Test Suite', function () {
+  it('duplicates', function () {
+    var word = new Isogram('duplicates');
+
+    expect(word.isIsogram()).toEqual(true);
+  });
+
+  it('eleven', function () {
+    var word = new Isogram('eleven');
+
+    expect(word.isIsogram()).toEqual(false);
+  });
+
+  it('subdermatoglyphic', function () {
+    var word = new Isogram('subdermatoglyphic');
+
+    expect(word.isIsogram()).toEqual(true);
+  });
+
+  it('Alphabet', function () {
+    var word = new Isogram('Alphabet');
+
+    expect(word.isIsogram()).toEqual(false);
+  });
+
+  it('thumbscrew-japingly', function () {
+    var word = new Isogram('thumbscrew-japingly');
+
+    expect(word.isIsogram()).toEqual(true);
+  });
+
+  it('Hjelmqvist-Gryb-Zock-Pfund-Wax', function () {
+    var word = new Isogram('Hjelmqvist-Gryb-Zock-Pfund-Wax');
+
+    expect(word.isIsogram()).toEqual(true);
+  });
+
+  it('Heizölrückstoßabdämpfung', function () {
+    var word = new Isogram('Heizölrückstoßabdämpfung');
+
+    expect(word.isIsogram()).toEqual(true);
+  });
+
+  it('the quick brown fox', function () {
+    var word = new Isogram('the quick brown fox');
+
+    expect(word.isIsogram()).toEqual(false);
+  });
+
+  it('Emily Jung Schwartzkopf', function () {
+    var word = new Isogram('Emily Jung Schwartzkopf');
+
+    expect(word.isIsogram()).toEqual(true);
+  });
+
+  it('éléphant', function () {
+    var word = new Isogram('éléphant');
+
+    expect(word.isIsogram()).toEqual(false);
+  });
+
+});