Catch when an invalid list filter is passed

Before, vgstash.DB.list_games() would default to 'allgames' and silently
hide it when a filter wasn't found. This commit ensures that the vgstash
package and CLI both indicate when an invalid filter is passed to them:

* vgstash.DB.list_games() will return False on a failure to match;
* vgstash_cli uses Click's Choice object to enforce the constraint

2 files changed, 13 insertions, 3 deletions

diff --git a/src/vgstash/__init__.py b/src/vgstash/__init__.py
index e3ede03..b3bd9b9 100755
--- a/src/vgstash/__init__.py
+++ b/src/vgstash/__init__.py
@@ -277,9 +277,17 @@ class DB(object):
         return ret
 
     def list_games(self, filter='allgames'):
+        """
+        Return a list of games that meet the filter criteria.
+
+        If the filter exists, it returns a list of sqlite3.Row objects. If the
+        filter does not exist, it returns False. If no filter is specified, it
+        will return a list of all games in the database.
+        """
         if filter not in FILTERS.keys():
-            filter = 'allgames'
-        return self.conn.execute(FILTERS[filter]).fetchall()
+            return False
+        else:
+            return self.conn.execute(FILTERS[filter]).fetchall()
 
     def update_filter(self, filter_name, stmt):
         """
diff --git a/src/vgstash_cli.py b/src/vgstash_cli.py
index 22cfc5a..db5853b 100644
--- a/src/vgstash_cli.py
+++ b/src/vgstash_cli.py
@@ -108,13 +108,15 @@ def add(title, system, ownership, progress, notes):
 
 
 @cli.command('list')
-@click.argument('filter', required=False, default="allgames")
+@click.argument('filter', type=click.Choice(vgstash.FILTERS.keys()), required=False, default="allgames")
 @click.option('--raw', '-r', is_flag=True, show_default=True, default=False, help="Output raw, pipe-delimited lines")
 @click.option('--width', '-w', type=str, required=False, default=get_terminal_size(fallback=(80,24)).columns, help="The width of the table to output, in characters.")
 def list_games(filter, raw, width):
     db = get_db()
     res = db.list_games(filter)
     first_pass = True
+    # res can be False if the filter doesn't exist, but Click should catch it
+    # and spit out an error before this function even starts.
     for r in res:
         if 'notes' in r.keys() and len(r['notes']) > 0:
             notes = r['notes'].replace('\n', '\\n')