Filtering Array of Objects Returns Empty Array

Question

I am trying to filter all objects in the projects array that are not in the savedProjects array but the result is an empty array. Am I filtering the wrong way?

My code:

router.post('/get-related', async (req, res) => {
console.log(req.body);
try {
    const projects = await Projects.find({researchers: req.body.fullname});
    let savedProjects = await Projects.find({projectID: req.body.projectsIDs});
    projects.filter(p => savedProjects.includes(p) === false);
    res.json(projects);
} catch (err) { 
    console.log(err);
    res.json({ message: err }) };
});

Answer 1

Using the $nin specification fixed it. I imported the saved projects and then queried all projects that did not include the ones in the savvedProjects array.

router.post('/get-related', async (req, res) => {
try {
    const savedProjects = await Projects.find({projectID: req.body.projectsIDs});
    let IDs = savedProjects.map(p => p.projectID);
    const projects = await Projects.find({ category: req.body.researcharea,  projectID: { $nin: IDs }});
    res.json(projects);
} catch (err) { res.json({ message: err }) };

});