Gulp: Object #<Object> has no method 'if'

Question

I have cloned a repo with a working gulpfile.js, and now when running gulf on the cloned repo, I received the error

Object #<Object> has no method 'if'

The offending task code: gulp.task('html', ['styles'], function () {

return gulp.src('app/*.html')
  .pipe($.useref.assets({searchPath: '{.tmp,app}'}))
  .pipe($.if('*.css', $.csso()))
  .pipe($.useref.restore())
  .pipe($.useref())
  .pipe(gulp.dest('dist'));
});

I have installed gulp-if and gulp-csso. $ is

var $ = require('gulp-load-plugins')();

Still learning gulp. Not sure where to go from here.

Answer 1

In package.json, gulp-if was not listed under devDependencies.

  "devDependencies": {
      .
      .
      .
      "gulp-if": "^1.2.5",

Including it eliminated the error.

Whenever installing a development dependency, I should affix --save-dev so the package is automatically placed in package.json, and then anyone cloning will automatically get all the packages in package.json by issuing the npm install command.

npm install <package> --save-dev