Fixed bug with human filter description, refs #189

We were showing this:

    201 rows where sorted by sortable_with_nulls

We now show this:

    201 rows sorted by sortable_with_nulls

datasette/templates/table.html

@@ -25,7 +25,7 @@
 
 {% if filtered_table_rows or human_description_en %}
     <h3>{% if filtered_table_rows or filtered_table_rows == 0 %}{{ "{:,}".format(filtered_table_rows) }} row{% if filtered_table_rows == 1 %}{% else %}s{% endif %}{% endif %}
-        {% if human_description_en %}where {{ human_description_en }}{% endif %}
+        {% if human_description_en %}{{ human_description_en }}{% endif %}
     </h3>
 {% endif %}
 

datasette/utils.py

@@ -475,7 +475,10 @@ class Filters:
             and_bits.append(', '.join(commas))
         if tail:
             and_bits.append(tail[0])
-        return ' and '.join(and_bits)
+        s = ' and '.join(and_bits)
+        if not s:
+            return ''
+        return 'where {}'.format(s)
 
     def selections(self):
         "Yields (column, lookup, value) tuples"

tests/test_api.py

@@ -388,6 +388,8 @@ def test_sortable_and_filtered(app_client):
     )
     response = app_client.get(path, gather_request=False)
     fetched = response.json['rows']
+    assert 'where content contains "d" sorted by sortable descending' \
+        == response.json['human_description_en']
     expected = [
         row for row in generate_sortable_rows(201)
         if 'd' in row['content']