         helper.unsetConfig 'atom-latex.bibtex'
         helper.unsetConfig 'atom-latex.compiler_param'
         helper.unsetConfig 'atom-latex.custom_toolchain'
-        helper.setConfig 'atom-latex.preview_after_build', false
+        helper.setConfig 'atom-latex.preview_after_build', 'Do nothing'
         pkg.latex.builder.build()
         expect(execCmd.callCount).toBe(4)
         expect(open).not.toHaveBeenCalled()

        expect(pkg.latex.server).toBeDefined()
        expect(pkg.latex.panel).toBeDefined()
        expect(pkg.latex.parser).toBeDefined()

  describe 'Builder', ->
    beforeEach ->

      execCmd = execCmd_ = open = open_ = undefined

      beforeEach ->
        waitsForPromise -> atom.packages.activatePackage('status-bar')
        open = jasmine.createSpy('open')
        stdout = jasmine.createSpy('stdout')
        execCmd = jasmine.createSpy('execCmd').andCallFake((cmd, cwd, fn) ->
