How to create repeating pipe in gulp?

Question

I have a gulp task to inject several dependencies in index.html as this :

return gulp.src(config.serve.html)
          .pipe($.inject(gulp.src(prependSource(config.inject.source.indexes)), {
            read: false,
            starttag: config.inject.indexes,
            addRootSlash: false,
            addPrefix: prefix,
            ignorePath: ignore
          }))
          .pipe($.inject(gulp.src(managerList), {
            read: false,
            starttag: config.inject.managers,
            addRootSlash: false,
            addPrefix: prefix,
            ignorePath: ignore
          }))
          .pipe($.inject(gulp.src(prependSource(config.inject.source.directives)), {
            read: false,
            starttag: config.inject.directives,
            addRootSlash: false,
            addPrefix: prefix,
            ignorePath: ignore
          }))

          .pipe($.inject(gulp.src(prependSource(config.inject.source.routes)), {
            read: false,
            starttag: config.inject.routes,
            addRootSlash: false,
            addPrefix: prefix,
            ignorePath: ignore
          }))
          .pipe($.inject(gulp.src(prependSource(config.inject.source.css)), {
            read: false,
            starttag: config.inject.css,
            addRootSlash: false,
            addPrefix: prefix,
            ignorePath: ignore
          }))


          .pipe($.size())
          .pipe(gulp.dest(dest));
};

As you can see, all the pipes are in repeating in some fashion (except the managerList). So what I want is to consolidate the repeating pipes into one single pipe, with the help of an array of injects. How to achieve the same?

Answer 1

gulp.src returns a stream (as does each .pipe). If you think about what each .pipe call is doing, you can simply turn it into a for loop. Something like this:

config = { /* your config object */ };

var stream = gulp.src(/* source glob */);
for (var i = 0; i < injects.length; i++) {
  stream = stream.pipe($.inject(gulp.src(prependSource(config.inject.source[i])), config.inject.starttag[i]));
}

stream.pipe($.size())
      .pipe(gulp.dest(dest));

return stream;