Adding the ability to specify the exponent used for determining the file size, and adding exponent as an output value (feature request by email)

Author: avoidwork

README.md

@@ -14,8 +14,11 @@ _***(number)***_ Number base, default is `2`
 ### bits
 _***(boolean)***_ Enables `bit` sizes, default is `false`
 
+### exponent
+_***(number)***_ Specifies the SI suffix via exponent, e.g. `2` is `MB` for bytes, default is `-1`
+
 ### output
-_***(string)***_ Output of function (`array`, `object`, or `string`), default is `string`
+_***(string)***_ Output of function (`array`, `exponent`, `object`, or `string`), default is `string`
 
 ### round
 _***(number)***_ Decimal place, default is `2`
@@ -40,6 +43,9 @@ filesize(265318, {round: 0});         // "259 kB"
 filesize(265318, {output: "array"});  // [259.1, "kB"]
 filesize(265318, {output: "object"}); // {value: 259.1, suffix: "kB"}
 filesize(1, {suffixes: {B: "Б"}});    // "1 Б"
+filesize(1024);                       // "1 kB"
+filesize(1024, {exponent: 0});        // "1024 B"
+filesize(1024, {output: "exponent"}); // 1
 ```
 
 ## How can I load filesize.js?

lib/filesize.js

@@ -6,7 +6,7 @@
  * @license BSD-3 <https://raw.github.com/avoidwork/filesize.js/master/LICENSE>
  * @link http://filesizejs.com
  * @module filesize
- * @version 3.0.0
+ * @version 3.0.1
  */
 ( function ( global ) {
 "use strict";
@@ -39,6 +39,7 @@ function filesize ( arg, descriptor ) {
 	spacer = descriptor.spacer !== undefined ? descriptor.spacer : unix ? "" : " ";
 	suffixes = descriptor.suffixes !== undefined ? descriptor.suffixes : {};
 	output = descriptor.output !== undefined ? descriptor.output : "string";
+	e = descriptor.exponent !== undefined ? descriptor.exponent : -1;
 	num = Number( arg );
 	neg = ( num < 0 );
 	ceil = base > 2 ? 1000 : 1024;
@@ -60,7 +61,10 @@ function filesize ( arg, descriptor ) {
 		}
 	}
 	else {
-		e = Math.floor( Math.log( num ) / Math.log( 1000 ) );
+		// Determining the exponent
+		if ( e === -1 || isNaN( e ) ) {
+			e = Math.floor( Math.log( num ) / Math.log( 1000 ) );
+		}
 
 		// Exceeding supported length, time to reduce & multiply
 		if ( e > 8 ) {
@@ -116,6 +120,9 @@ function filesize ( arg, descriptor ) {
 	if ( output === "array" ) {
 		return result;
 	}
+	else if ( output === "exponent" ) {
+		return e;
+	}
 	else if ( output === "object" ) {
 		return { value: result[ 0 ], suffix: result[ 1 ] };
 	}

lib/filesize.min.js

@@ -1,7 +1,7 @@
 {
   "name": "filesize",
   "description": "JavaScript library to generate a human readable String describing the file size",
-  "version": "3.0.0",
+  "version": "3.0.1",
   "homepage": "http://filesizejs.com",
   "author": {
     "name": "Jason Mulligan",

lib/filesize.min.js.map

@@ -24,6 +24,7 @@ function filesize ( arg, descriptor ) {
 	spacer = descriptor.spacer !== undefined ? descriptor.spacer : unix ? "" : " ";
 	suffixes = descriptor.suffixes !== undefined ? descriptor.suffixes : {};
 	output = descriptor.output !== undefined ? descriptor.output : "string";
+	e = descriptor.exponent !== undefined ? descriptor.exponent : -1;
 	num = Number( arg );
 	neg = ( num < 0 );
 	ceil = base > 2 ? 1000 : 1024;
@@ -45,7 +46,10 @@ function filesize ( arg, descriptor ) {
 		}
 	}
 	else {
-		e = Math.floor( Math.log( num ) / Math.log( 1000 ) );
+		// Determining the exponent
+		if ( e === -1 || isNaN( e ) ) {
+			e = Math.floor( Math.log( num ) / Math.log( 1000 ) );
+		}
 
 		// Exceeding supported length, time to reduce & multiply
 		if ( e > 8 ) {
@@ -101,6 +105,9 @@ function filesize ( arg, descriptor ) {
 	if ( output === "array" ) {
 		return result;
 	}
+	else if ( output === "exponent" ) {
+		return e;
+	}
 	else if ( output === "object" ) {
 		return { value: result[ 0 ], suffix: result[ 1 ] };
 	}

package.json

@@ -11,7 +11,7 @@ exports["filesize"] = {
 		done();
 	},
 	base2: function (test) {
-		test.expect(37);
+		test.expect(39);
 
 		test.equal(filesize(this.kilobit),                             "500 B",    "Should be '500 B'");
 		test.equal(filesize(this.kilobit, {round: 1}),                 "500 B",    "Should be '500 B'");
@@ -30,6 +30,8 @@ exports["filesize"] = {
 		test.equal(filesize(this.kilobyte, {bits :true}),              "8 kb",     "Should be '8 kb'");
 		test.equal(filesize(this.kilobyte, {round: 1, bits: true}),    "8 kb",     "Should be '8 kb'");
 		test.equal(filesize(this.kilobyte, {unix: true, bits: true}),  "8k",       "Should be '8k'");
+		test.equal(filesize(this.kilobyte, {exponent: 0}),             "1024 B",   "Should be '1024 B'");
+		test.equal(filesize(this.kilobyte, {output: "exponent"}),      1,          "Should be '1'");
 
 		test.equal(filesize(this.neg),                                 "-1 kB",    "Should be '-1 kB'");
 		test.equal(filesize(this.neg, {round: 1}),                     "-1 kB",    "Should be '-1 kB'");