Inserting specific file at index of a stream - gulp

Question

Basicly this gulp script finds the 'file1,file2,file3' in a folder, builds its dependencies (which are in the same folder) and add it all to 1 file.
Now, my problem is, i have a custom file which i have to put in after file2. How can i achieve this?
function gatherAMD(stream, file) {
var moduleId = file.path.match(/file\.(.+)\.js/)[1];
return stream.pipe(amdOptimize(`file.${moduleId}`, {
baseUrl: "fileslocation/location",
exclude: [ 'jquery' ]
}));
}
gulp.task("js", function() {
var included = [];
var files = "file1,file2,file3"
var stream = null;
if (files.indexOf(",") == -1) {
stream = gulp.src('fileslocation/location/file.'+ files+ '.js', { base: "fileslocation/location"});
} else {
stream = gulp.src(`fileslocation/location/file.{${files}}.js`, { base: "fileslocation/location"});
}
return stream.pipe(debug())
.pipe(foreach(gatherAMD))
.pipe(filter(function(file) {
if (included.indexOf(file.path) === -1) {
included.push(file.path);
return true;
} else {
return false;
}
}))
.pipe(concat({path: 'fileslocation/custom.js', base: 'fileslocation'}))
.pipe(gulp.dest("fileslocation"));
});

Answer 1

You can probably use map for checking the current file in the stream, and then adding it from some logic and then using gulp-inject to add a file to the stream.
Something like,
return stream.pipe(debug())
.pipe(foreach(gatherAMD))
.pipe(filter(function(file) {
if (included.indexOf(file.path) === -1) {
included.push(file.path);
return true;
} else {
return false;
}
}))
.pipe(map(function(file, callback) {
if (file.relative === 'file2.js') {
// inject file to the stream here
}
callback(null, file);
}))
.pipe(concat({path: 'fileslocation/custom.js', base: 'fileslocation'}))
.pipe(gulp.dest("fileslocation"));