rewrite in typescript and update tests

.editorconfig

@@ -0,0 +1,14 @@
+# editorconfig.org
+root = true
+
+[*]
+indent_style = space
+indent_size = 2
+end_of_line = lf
+charset = utf-8
+trim_trailing_whitespace = true
+insert_final_newline = false
+
+[*.md]
+trim_trailing_whitespace = false
+insert_final_newline = false

.nycrc

@@ -0,0 +1,3 @@
+{
+  "extends": "@istanbuljs/nyc-config-typescript"
+}

package.json

@@ -2,8 +2,10 @@
   "name": "readable-timespan",
   "version": "1.2.0",
   "description": "Human readable timespans",
-  "main": "index.js",
+  "main": "dist/index.js",
   "scripts": {
+    "build": "tsc",
+    "watch": "tsc -w",
     "test": "nyc ava"
   },
   "repository": {
@@ -27,11 +29,20 @@
   },
   "homepage": "https://github.com/aurbano/readable-timespan",
   "devDependencies": {
-    "ava": "^0.17.0",
-    "coveralls": "^2.11.15",
-    "nyc": "^10.0.0"
+    "@istanbuljs/nyc-config-typescript": "^0.1.3",
+    "ava": "^2.4.0",
+    "coveralls": "^3.0.7",
+    "nyc": "^14.1.1",
+    "ts-node": "^8.5.2",
+    "typescript": "^3.7.2"
   },
-  "dependencies": {
-    "extend": "^3.0.0"
+  "ava": {
+    "compileEnhancements": false,
+    "extensions": [
+      "ts"
+    ],
+    "require": [
+      "ts-node/register"
+    ]
   }
 }

src/index.ts

@@ -0,0 +1,99 @@
+import { Options, Increments } from './types';
+/**
+ * readable-timespans
+ * Get human-readable timespans from time intervals in milliseconds
+ *
+ * @author Alejandro U. Alvarez <https://aurbano.eu>
+ * @license MIT
+ */
+
+/**
+ * Adjust this definition if you want
+ * this assumes all months have 30 days, every year
+ * 365 days, and every month 4 weeks. Since it is only
+ * to give a very rough estimate of the time elapsed it should
+ * be fine though.
+ */
+const MILLISECOND = 1,
+      SECOND = 1000 * MILLISECOND,
+      MINUTE = 60 * SECOND,
+      HOUR = 60 * MINUTE,
+      DAY = 24 * HOUR,
+      WEEK = 7 * DAY,
+      MONTH = 30 * DAY,
+      YEAR = 365 * DAY;
+
+const defaultSettings: Options = {
+  lessThanFirst: 'now',
+  millisecond: 'millisecond',
+  second: 'second',
+  minute: 'minute',
+  hour: 'hour',
+  day: 'day',
+  week: 'week',
+  month: 'month',
+  year: 'year',
+  now: 'now',
+  space: true,
+  pluralize: true
+};
+
+export class Timespan {
+  settings: Options;
+  increments: Increments;
+
+  constructor(options?: Options) {
+    this.settings = {
+      ...defaultSettings,
+      ...options,
+    };
+
+    this.increments = [
+      [MILLISECOND, this.settings.millisecond],
+      [SECOND, this.settings.second],
+      [MINUTE, this.settings.minute],
+      [HOUR, this.settings.hour],
+      [DAY, this.settings.day],
+      [WEEK, this.settings.week],
+      [MONTH, this.settings.month],
+      [YEAR, this.settings.year],
+    ];
+  };
+
+  public parse(diff: number): string {
+    let plural = '',
+        space = ' ',
+        checkValid = 0,
+        units = Math.ceil(diff / this.increments[this.increments.length - 1][0]),
+        unit = this.increments[this.increments.length - 1][1];
+
+    // Handle units smaller than the first increment
+    while (!this.increments[checkValid][1]) {
+      checkValid++;
+    }
+
+    if (diff < this.increments[checkValid][0]) {
+      return this.settings.lessThanFirst;
+    }
+
+    for (let i = 1; i < this.increments.length; i++) {
+      if (!this.increments[i - 1][1]) continue;
+
+      if (this.increments[i - 1][0] <= diff && diff < this.increments[i][0]) {
+        units = Math.ceil(diff / this.increments[i - 1][0]);
+        unit = this.increments[i - 1][1];
+        break;
+      }
+    }
+
+    if (units > 1 && this.settings.pluralize) {
+      plural = 's';
+    }
+
+    if (!this.settings.space) space = '';
+
+    return units + space + unit + plural;
+  }
+}
+
+export default Timespan;

src/types.ts

@@ -0,0 +1,16 @@
+export type Options = {
+  lessThanFirst?: string,
+  millisecond?: string | false,
+  second?: string | false,
+  minute?: string | false,
+  hour?: string | false,
+  day?: string | false,
+  week?: string | false,
+  month?: string | false,
+  year?: string | false,
+  now?: string,
+  space?: boolean,
+  pluralize?: boolean,
+};
+
+export type Increments = Array<[number, string | false]>;