[enb#425] change test for techs/write-file.js. Added checking of file…

…'s content

test/techs/write-file.test.js

@@ -23,28 +23,15 @@ describe('techs/write-file', function () {
         mockFS.restore();
     });
 
-    it('should get error if param "content" in undefined', function () {
-        (function () {
-            bundle.runTech(WriteFileTech, {
-                target: '?.bemjson.js'
-            })
-            .should.be.rejectedWith('Error: Option "content" is required for technology "write-file".')
-            .then(function () {
-                rejectSpy.should.calledWith('bundle.bemjson.js');
-            });
-        }).should.throw('Option "content" is required for technology "write-file".');
-    });
-
     it('should write target file to file system', function () {
         return bundle.runTech(WriteFileTech, {
                 target: '?.txt',
                 content: 'I\'m here'
             })
             .should.be.fulfilled
             .then(function () {
-                require('fs').statSync('bundle/bundle.txt').isFile().should.be.ok;
-
                 resolveSpy.should.calledWith('bundle.txt');
+                require('fs').readFileSync('bundle/bundle.txt').toString().to.deep.equal('I\'m here')
             });
     });
 });