test(gulp): add tests for gulp-prefixer

Author: azu

src/gulp/gulp-prefixer.js

@@ -1,18 +1,18 @@
 "use strict";
 import {Transform} from "stream";
-let prefixBuffer = function (buffer, prefix) {
+export function prefixBuffer(buffer, prefix) {
     return Buffer.concat([Buffer(prefix), buffer]);
-};
+}
 
-let prefixStream = function (prefix) {
+export function prefixStream(prefix) {
     return new Transform({
         transform: function (chunk, encoding, next) {
             let buffer = prefixBuffer(chunk, prefix);
             this.push(buffer);
             next();
         }
     });
-};
+}
 
 let gulpTransform = function (prefix) {
     // enable `objectMode` of the stream for vinyl File objects.

test/gulp/fixtures/text.txt

@@ -0,0 +1 @@
+text

test/gulp/gulp-prefixer-test.js

@@ -0,0 +1,28 @@
+// LICENSE : MIT
+"use strict";
+import assert from "power-assert";
+import {createReadStream} from "fs";
+import {prefixBuffer, prefixStream} from "../../src/gulp/gulp-prefixer";
+describe("gulp-prefixer-test", function () {
+    describe("#prefixBuffer", function () {
+        it("should add prefix text to buffer", function () {
+            let result = prefixBuffer(Buffer("text"), "prefix");
+            assert.equal(result.toString(), "prefixtext");
+        });
+    });
+    describe("#prefixStream", function () {
+        it("should add prefix text to stream", function (done) {
+            let buffer = "";
+            let stream = createReadStream(__dirname + "/fixtures/text.txt");
+            stream.pipe(prefixStream("prefix"))
+                .on("data", function (chunk) {
+                    buffer += chunk;
+                })
+                .on("end", function () {
+                    assert.equal(buffer.toString(), "prefixtext");
+                    done();
+                });
+        });
+    });
+
+});