diff --git a/.gitignore b/.gitignore
index e1fdfa2..ae51308 100644
--- a/.gitignore
+++ b/.gitignore
@@ -128,3 +128,6 @@ dmypy.json
 # Pyre type checker
 .pyre/
 mapshader/_version.py
+
+# VS code stuff
+.vscode
\ No newline at end of file
diff --git a/mapshader/flask_app.py b/mapshader/flask_app.py
index f987ce2..9f012a4 100644
--- a/mapshader/flask_app.py
+++ b/mapshader/flask_app.py
@@ -1,6 +1,7 @@
 from functools import partial
 import sys
 
+from bokeh.models.sources import GeoJSONDataSource
 from bokeh.plotting import figure
 from bokeh.models.tiles import WMTSTileSource
 from bokeh.embed import components
@@ -109,7 +110,19 @@ def build_previewer(service: MapService):
     p.axis.visible = True
 
     if service.service_type == 'tile':
+        tile_source = WMTSTileSource(url=service.client_url,
+                                     min_zoom=0,
+                                     max_zoom=15)
+
+        p.add_tile(tile_source, render_parents=False)
+
+    elif service.service_type == 'geojson':
+        geo_source = GeoJSONDataSource(geojson=render_geojson(service.source))
+
+        p.patches('xs', 'ys', line_color='white', line_width=0.5, source=geo_source)
 
+    elif service.service_type == 'image':
+        # Bokeh ImageRGBA...?
         tile_source = WMTSTileSource(url=service.client_url,
                                      min_zoom=0,
                                      max_zoom=15)
diff --git a/mapshader/tests/test_services_directory.py b/mapshader/tests/test_services_directory.py
new file mode 100644
index 0000000..25e6db2
--- /dev/null
+++ b/mapshader/tests/test_services_directory.py
@@ -0,0 +1,40 @@
+from bokeh.plotting.figure import Figure
+import pytest
+
+from mapshader.flask_app import build_previewer
+from mapshader.services import GeoJSONService, TileService
+from mapshader.sources import MapSource, world_countries_source
+
+
+def test_build_previewer_with_point_data_source():
+    source_dict = world_countries_source()
+    map_source = MapSource.from_obj(source_dict)
+    tile_service = TileService(map_source)
+    result = build_previewer(tile_service)
+    assert isinstance(result, Figure)
+
+def test_build_previewer_with_geojson_service_type():
+    source_dict = world_countries_source()
+    map_source = MapSource.from_obj(source_dict)
+    geojson_service = GeoJSONService(map_source)
+    result = build_previewer(geojson_service)
+
+    assert isinstance(result, Figure)
+
+def test_build_previewer_with_geojson_geometry_collection_service_type():
+    source_dict = world_countries_source()
+    map_source = MapSource.from_obj(source_dict)
+    geojson_service = GeoJSONService(map_source)
+    result = build_previewer(geojson_service)
+
+    assert isinstance(result, Figure)
+
+def test_build_previewer_with_bad_data():
+    source_dict = world_countries_source()
+    map_source = MapSource.from_obj(source_dict)
+
+    map_service = TileService(map_source)
+    map_service.source = None
+
+    with pytest.raises(AttributeError):
+        build_previewer(map_service)