Flutter query snapshot - map to list if conditional is met

[OGmetamonkey]

I am mapping a Firestore query snapshot to a listview of listtiles. I only want to map values with }).toList(), that contain a certain search word "testSearch".

I wrote the following code, but it simply maps the whole list or doesn't map anything, based on the first conditional:

(if (testVal.contains(testSearch) || testSearch == null || testSearch == '') {).

I actually need to check the 'entry" value prior to the .toList() function based on my search word, but I can't figure it out.

There are a few other questions slightly related on stack out there, but they either don't handle streams, or they require me to bloat the code. It seems like there would be a more elegant solution. Here are the other related Q's:
https://stackoverflow.com/questions/50567295/listview-filter-search-in-flutter
https://stackoverflow.com/questions/61024941/flutter-change-list-based-on-variable-number

 Expanded(
  child: 
  FutureBuilder(
    future: FirebaseAuth.instance.currentUser(),
    builder: (context, AsyncSnapshot<FirebaseUser> snapshot) {
    if (snapshot.hasData) {
      return StreamBuilder<QuerySnapshot>(
      stream: Firestore.instance.collection('users').document(snapshot.data.uid).collection('stuff').snapshots(),
      builder: (BuildContext context, AsyncSnapshot<QuerySnapshot> querySnapShot){
        if(querySnapShot.connectionState == ConnectionState.waiting){
          return CircularProgressIndicator();
        }else{
          for (var doc in querySnapShot.data.documents) {
            String testVal = DBProvider.db.idDecoder(doc['id'], keycode));
            String testSearch = 'test';
            if (testVal.contains(testSearch) || testSearch == null || testSearch == '') {
              return new ListView(
              children: querySnapShot.data.documents.asMap().entries.map((entry) {
                _acts.add(false); 
                int index = entry.key;
                DocumentSnapshot document = entry.value;
                  return new ListTile(
                  leading: _acts[index] != false ? const Icon(Icons.remove_red_eye, color: Color(0xff00caff), size: 40) : const Icon(Icons.remove_red_eye, color: Color(0xffE7C24A), size: 40),
                  title: new Text((DBProvider.db.idDecoder(document['id'], keycode) ?? 'url'), style: TextStyle(color: primaryColor)),
                  trailing: IconButton(icon: Icon(Icons.content_copy, color: Color(0xffE7C24A), size: 20), //edit
                    onPressed: () {
                    Clipboard.setData(new ClipboardData(text: DBProvider.db.decoder(document['textStuff'],keycode)));
                      _scaffoldKey.currentState.showSnackBar(SnackBar(
                      content: Text(
                      'Copied text for ' + (DBProvider.db.idDecoder(document['id'], keycode)),
                      ),
                      duration: Duration(seconds: 2),
                      ));
                  }),
                  subtitle: _acts[index] != false ? new Text(("username: " + (DBProvider.db.usernameDecoder(document['id'], keycode)) ?? 'unlock your stuff'), style: TextStyle(color: secondaryColor)) : null,
                  onTap: () { 
                                navigateToView(document, keycode);
                    },
                    onLongPress: () {
                                      setState(() { // new line
                      _acts[index] = !_acts[index];
                        print(_acts[index].toString());
                      });
                    },
                  );
              }).toList(),
            } else {
              return Container();
            }
})})}})),