Merge pull request #8 from millerized/version-1

Fix: #7 off-by-one issue, tons of hygiene improvements including transpilation

.babelrc

@@ -0,0 +1,12 @@
+{
+    "presets": [
+        [
+            "env",
+            {
+                "targets": {
+                    "browsers": ["last 2 versions", "IE >= 10"]
+                }
+            }
+        ]
+    ]
+}

dist/smart-truncate.es5.js

@@ -0,0 +1,41 @@
+'use strict';
+
+/**
+ * smartTruncate - Smartly™ truncate a given string.
+ *
+ * @param  {String} string      A string with a minimum lenght of 4 chars.
+ * @param  {Number} length      The length of the truncated result.
+ * @param  {Number} [position]  The index of the ellipsis (zero based). Default is the end.
+ * @return {String}             Return a truncated string w/ ellipsis.
+ *
+ * Example: smartTruncate('Steve Miller', 8) === 'Steve M…'.
+ * Example: smartTruncate('Steve Miller', 9, 4) === 'Stev…ller'.
+ */
+var smartTruncate = function smartTruncate(string, length) {
+    var position = arguments.length > 2 && arguments[2] !== undefined ? arguments[2] : length;
+
+    var ellipsisOffset = 1;
+    var minLength = 4;
+
+    var str = string;
+
+    if (typeof str === 'string') {
+        str = str.trim();
+    }
+
+    var invalid = typeof str !== 'string' || str.length < minLength || typeof length !== 'number' || length <= minLength || length >= str.length - ellipsisOffset;
+
+    if (invalid) return string;
+
+    if (position >= length - ellipsisOffset) {
+        var _start = str.substring(0, length - ellipsisOffset);
+        return _start + '\u2026';
+    }
+
+    var start = str.substring(0, position);
+    var end = str.slice(position + ellipsisOffset - length);
+
+    return start + '\u2026' + end;
+};
+
+module.exports = smartTruncate;

package.json

@@ -2,10 +2,13 @@
   "name": "smart-truncate",
   "version": "0.0.5",
   "description": "A small library that truncates a string. It can insert or append an ellipsis at any desired position of the truncated result.",
-  "main": "smart-truncate.js",
+  "main": "dist/smart-truncate.es5.js",
   "scripts": {
-    "test": "node_modules/.bin/mocha --reporter spec",
-    "cover": "node_modules/istanbul/lib/cli.js cover node_modules/mocha/bin/_mocha -- -R spec test/*"
+    "test": "node_modules/.bin/mocha -R spec src/*.spec.js",
+    "cover": "node_modules/istanbul/lib/cli.js cover node_modules/.bin/_mocha -- -R spec src/*.spec.js",
+    "cover:dev": "npm run compile && npm run cover",
+    "compile": "./node_modules/.bin/babel src/smart-truncate.js --out-file dist/smart-truncate.es5.js",
+    "build": "npm run compile"
   },
   "repository": {
     "type": "git",
@@ -24,9 +27,11 @@
   },
   "homepage": "https://github.com/millerized/smart-truncate#readme",
   "devDependencies": {
-    "chai": "^3.5.0",
-    "coveralls": "^2.11.14",
+    "babel-cli": "^6.26.0",
+    "babel-preset-env": "^1.6.1",
+    "chai": "^4.1.2",
+    "coveralls": "^3.0.0",
     "istanbul": "^0.4.5",
-    "mocha": "^3.1.2"
+    "mocha": "^4.1.0"
   }
 }

smart-truncate.js → src/smart-truncate.js

@@ -7,11 +7,12 @@
  * @return {String}             Return a truncated string w/ ellipsis.
  *
  * Example: smartTruncate('Steve Miller', 8) === 'Steve M…'.
- * Example: smartTruncate('Steve Miller', 9, 5) === 'Stev…ller'.
+ * Example: smartTruncate('Steve Miller', 9, 4) === 'Stev…ller'.
  */
-module.exports = function smartTruncate(string, length, position = length) {
+const smartTruncate = (string, length, position = length) => {
     const ellipsisOffset = 1;
     const minLength = 4;
+
     let str = string;
 
     if (typeof str === 'string') {
@@ -26,7 +27,7 @@ module.exports = function smartTruncate(string, length, position = length) {
 
     if (invalid) return string;
 
-    if (position >= length) {
+    if (position >= (length - ellipsisOffset)) {
         const start = str.substring(0, length - ellipsisOffset);
         return `${start}…`;
     }
@@ -36,3 +37,5 @@ module.exports = function smartTruncate(string, length, position = length) {
 
     return `${start}…${end}`;
 }
+
+module.exports = smartTruncate;

test/test.js → src/smart-truncate.spec.js

@@ -1,64 +1,83 @@
 'use strict';
 
-const expect = require('chai').expect;
-const smartTruncate = require('../smart-truncate');
+const {expect} = require('chai');
+const smartTruncate = require('../dist/smart-truncate.es5');
 
-describe('smartTruncate(string, length[, position])', function() {
-    it('should return a smart truncated string w/ an ellipsis at the 4th index position of the given string', function() {
+describe('smartTruncate(string, length[, position])', () => {
+    it('should return a smart truncated string w/ an ellipsis at the 4th index position of the given string', () => {
         expect(smartTruncate('Steve Miller', 9, 4)).to.equal('Stev…ller');
     });
 
-    it('should assert that the length of the truncated string is equal to the given length w/ an ellipsis at the 4th index position', function() {
+    it('should assert that the length of the truncated string is equal to the given length w/ an ellipsis at the 4th index position', () => {
         const length = 9;
         const truncated = smartTruncate('Steve Miller', length, 4);
         expect(truncated.length).to.equal(length);
     });
 
-    it('should append an ellipsis to the end of the truncated string (default) when given an undefined position', function() {
+    it('should append an ellipsis to the end of the truncated string (default) when given an undefined position', () => {
         expect(smartTruncate('Steve Miller', 8)).to.equal('Steve M…');
     });
 
-    it('should assert that the length of the truncated string is equal to the given length w/ an ellipsis at the default end of the string', function() {
+    it('should assert that the length of the truncated string is equal to the given length w/ an ellipsis at the default end of the string', () => {
         const length = 8;
         const truncated = smartTruncate('Steve Miller', length);
         expect(truncated.length).to.equal(length);
     });
 
-    it('should return a smart truncated string w/ an ellipsis at the 5th index position of the given string', function() {
+    it('should return a smart truncated string w/ an ellipsis at the 5th index position of the given string', () => {
         expect(smartTruncate('Steve Miller', 9, 5)).to.equal('Steve…ler');
     });
 
-    it('should return a smart truncated string w/ an ellipsis at the 8th index position of the given string', function() {
+    it('should return a smart truncated string w/ an ellipsis at the 8th index position of the given string', () => {
         expect(smartTruncate('Not a good fit', 12, 8)).to.equal('Not a go…fit');
     });
 
-    it('should return the given string when given a length that is larger than the given string', function() {
+    it('should return the given string when given a length that is larger than the given string', () => {
         expect(smartTruncate('Steve Miller', 14)).to.equal('Steve Miller');
     });
 
-    it('should return the given string when given a length that will end up replacing 1 char with an ellipsis (noop)', function() {
+    it('should return the given string when given a length that will end up replacing 1 char with an ellipsis (noop)', () => {
         expect(smartTruncate('Steve Miller', 11)).to.equal('Steve Miller');
     });
 
-    it('should append an ellipsis to the end of the truncated string when given a position that is larger than the given string and length', function() {
+    it('should append an ellipsis to the end of the truncated string when given a position that is larger than the given string and length', () => {
         expect(smartTruncate('Steve Miller', 10, 14)).to.equal('Steve Mil…');
     });
 
-    it('should return the given string when given an undefined length', function() {
+    it('should return the given string when given an undefined length', () => {
         expect(smartTruncate('Steve Miller')).to.equal('Steve Miller');
     });
 
-    it('should return the given string when given a String that has a length of less than the minimum 4 chars', function() {
+    it('should return the given string when given a String that has a length of less than the minimum 4 chars', () => {
         expect(smartTruncate('Ste', 2)).to.equal('Ste');
     });
 
-    it('should return the given string when given a String that has trailing whitespace and becomes trimmed to less than the minimum 4 chars in length', function() {
+    it('should return the given string when given a String that has trailing whitespace and becomes trimmed to less than the minimum 4 chars in length', () => {
         expect(smartTruncate('Ste ', 2)).to.equal('Ste ');
     });
 
-    it('should return the original, given value when given a non-String value', function() {
+    it('should return the original, given value when given a non-String value', () => {
         expect(smartTruncate(1000, 3)).to.equal(1000);
         expect(smartTruncate(undefined, 3)).to.equal(undefined);
         expect(smartTruncate(null, 3)).to.equal(null);
     });
+
+    // ref: https://github.com/millerized/smart-truncate/issues/7
+    it('should assert the correct index of the given position and length of truncated result', () => {
+        const str = 'abcdefghijklmnopqrstuvwxyz ABCDEFGHIJKLMNOPQRSTUVWXYZ abcdefghijklmnopqrstuvwxyz';
+        const length = 50;
+        const ellipsisOffset = 1;
+
+        for (var i = length; i > -1; i--) {
+            const expectedIndex = (i >= (length - ellipsisOffset))
+                ? (length - 1)
+                : i;
+
+            const truncated = smartTruncate(str, length, i);
+            const resultIndex = truncated.indexOf('…');
+
+            expect(resultIndex).to.equal(expectedIndex);
+            expect(truncated.length).to.equal(length)
+        }
+    });
 });