Added overloads to gul-if and added documentation

gulp-if/gulp-if-tests.ts

@@ -1,10 +1,22 @@
 /// <reference path="./gulp-if.d.ts"/>
 /// <reference path="../gulp/gulp.d.ts"/>
-import gulp = require("gulp");
-import _if = require("gulp-if");
+import gulp = require('gulp');
+import _if = require('gulp-if');
 
-gulp.src("test.css")
-    .pipe(_if(true, gulp.src("test.css")));
+gulp.src('test.css')
+    .pipe(_if(true, gulp.src('test.css')));
 
-gulp.src("test.css")
-    .pipe(_if(false, gulp.src("test.css"), gulp.src("test.css")));
+gulp.src('test.css')
+    .pipe(_if(false, gulp.src('test.css'), gulp.src('test.css')));
+    
+gulp.src('test.css')
+    .pipe(_if({isDirectory: true}, gulp.src('test.css')));
+
+gulp.src('test.css')
+    .pipe(_if({isFile: true}, gulp.src('test.css')));
+    
+gulp.src('test.css')
+    .pipe(_if(file => true, gulp.src('test.css')));
+    
+gulp.src('test.css')
+    .pipe(_if(/.*?\.css/, gulp.src('test.css')));

gulp-if/gulp-if.d.ts

@@ -1,14 +1,64 @@
 // Type definitions for gulp-if
 // Project: https://github.com/robrich/gulp-if
-// Definitions by: Asana <https://asana.com>
+// Definitions by: Asana <https://asana.com>, Joe Skeen <http://github.com/joeskeen>
 // Definitions: https://github.com/borisyankov/DefinitelyTyped
 
 /// <reference path="../node/node.d.ts"/>
+/// <reference path="../vinyl/vinyl.d.ts"/>
 
-declare module "gulp-if" {
-    function gulpIf(
-        condition: boolean,
-        stream: NodeJS.ReadWriteStream,
-        elseStream?: NodeJS.ReadWriteStream): NodeJS.ReadWriteStream;
+declare module 'gulp-if' {
+    import fs = require('fs');
+    import vinyl = require('vinyl');
+    
+    interface GulpIf {
+        /** 
+         * gulp-if will pipe data to stream whenever condition is truthy.
+         * If condition is falsey and elseStream is passed, data will pipe to elseStream
+         * After data is piped to stream or elseStream or neither, data is piped down-stream.
+         * 
+         * @param condition whether input should be piped to stream
+         * @param stream the stream to pipe to if condition is true
+         * @param elseStream (optional) the stream to pipe to if condition is false 
+         */
+        (condition: boolean, stream: NodeJS.ReadWriteStream, elseStream?: NodeJS.ReadWriteStream): NodeJS.ReadWriteStream;
+        /** 
+         * gulp-if will pipe data to stream whenever condition is truthy.
+         * If condition is falsey and elseStream is passed, data will pipe to elseStream
+         * After data is piped to stream or elseStream or neither, data is piped down-stream.
+         * 
+         * @param condition a Node Stat filter condition to be executed on the vinyl file's Stats object
+         * @param stream the stream to pipe to if condition is true
+         * @param elseStream (optional) the stream to pipe to if condition is false 
+         */
+        (condition: StatFilterCondition, stream: NodeJS.ReadWriteStream, elseStream?: NodeJS.ReadWriteStream): NodeJS.ReadWriteStream;
+        /** 
+         * gulp-if will pipe data to stream whenever condition is truthy.
+         * If condition is falsey and elseStream is passed, data will pipe to elseStream
+         * After data is piped to stream or elseStream or neither, data is piped down-stream.
+         * 
+         * @param condition a function taking a vinyl file and returning a boolean
+         * @param stream the stream to pipe to if condition is true
+         * @param elseStream (optional) the stream to pipe to if condition is false 
+         */
+        (condition: (fs: vinyl) => boolean, stream: NodeJS.ReadWriteStream, elseStream?: NodeJS.ReadWriteStream): NodeJS.ReadWriteStream;
+        /** 
+         * gulp-if will pipe data to stream whenever condition is truthy.
+         * If condition is falsey and elseStream is passed, data will pipe to elseStream
+         * After data is piped to stream or elseStream or neither, data is piped down-stream.
+         * 
+         * @param condition a RegularExpression that works on the file.path
+         * @param stream the stream to pipe to if condition is true
+         * @param elseStream (optional) the stream to pipe to if condition is false 
+         */
+        (condition: RegExp, stream: NodeJS.ReadWriteStream, elseStream?: NodeJS.ReadWriteStream): NodeJS.ReadWriteStream;
+    }
+    
+    interface StatFilterCondition {
+        isDirectory?: boolean; 
+        isFile?: boolean;
+    }
+    
+    var gulpIf: GulpIf; 
+    
     export = gulpIf;
 }