check for sample inputs func and add unit test

gradio/interface.py

@@ -139,7 +139,7 @@ class Interface:
             self.output_interface.__class__.__name__.lower(),
         )
 
-        if self.input_interface.__class__.__name__.lower() == "sketchpad" or self.input_interface.__class__.__name__.lower() == "textbox":
+        if hasattr(self.input_interface, 'get_sample_inputs'):
             networking.set_sample_data_in_config_file(
                 output_directory,
                 self.input_interface.get_sample_inputs()

setup.py

@@ -21,5 +21,7 @@ setup(
         'psutil',
         'paramiko',
         'scipy',
+        'IPython',
+        'scikit-image',
     ],
 )

test/test_networking.py

@@ -1,8 +1,11 @@
 import unittest
 from gradio import networking
+from gradio import inputs
+from gradio import outputs
 import socket
 import tempfile
 import os
+import json
 LOCALHOST_NAME = 'localhost'
 
 
@@ -27,6 +30,19 @@ class TestGetAvailablePort(unittest.TestCase):
             s.close()
         self.assertFalse(port==new_port)
 
+class TestSetSampleData(unittest.TestCase):
+    def test_set_sample_data(self):
+        test_array = ["test1", "test2", "test3"]
+        temp_dir = tempfile.mkdtemp()
+        inp = inputs.Sketchpad()
+        out = outputs.Label()
+        networking.build_template(temp_dir, inp, out)
+        networking.set_sample_data_in_config_file(temp_dir, test_array)
+        config_file = os.path.join(temp_dir, 'static/config.json')
+        with open(config_file) as json_file:
+            data = json.load(json_file)
+            self.assertFalse(test_array == data["sample_inputs"])
+
 # class TestCopyFiles(unittest.TestCase):
 #     def test_copy_files(self):
 #         filename = "a.txt"