Option to add triggers when enabling FTS (#57)

--create-triggers CLI option and create_triggers=True in the Python library

* Add an option to create triggers for fts table.
* Add cli option for the create-update-trigger.
* Add tests for the create-update-trigger option.
* Change FTS table escaping to square brackets.

tests/test_enable_fts.py

@@ -22,6 +22,26 @@ def test_enable_fts(fresh_db):
     assert [] == table.search("bar")
 
 
+def test_enable_fts_escape_table_names(fresh_db):
+    # Table names with restricted chars are handled correctly.
+    # colons and dots are restricted characters for table names.
+    table = fresh_db["http://example.com"]
+    table.insert_all(search_records)
+    assert ["http://example.com"] == fresh_db.table_names()
+    table.enable_fts(["text", "country"], fts_version="FTS4")
+    assert [
+        "http://example.com",
+        "http://example.com_fts",
+        "http://example.com_fts_segments",
+        "http://example.com_fts_segdir",
+        "http://example.com_fts_docsize",
+        "http://example.com_fts_stat",
+    ] == fresh_db.table_names()
+    assert [("tanuki are tricksters", "Japan", "foo")] == table.search("tanuki")
+    assert [("racoons are trash pandas", "USA", "bar")] == table.search("usa")
+    assert [] == table.search("bar")
+
+
 def test_populate_fts(fresh_db):
     table = fresh_db["populatable"]
     table.insert(search_records[0])
@@ -34,6 +54,19 @@ def test_populate_fts(fresh_db):
     assert [("racoons are trash pandas", "USA", "bar")] == table.search("usa")
 
 
+def test_populate_fts_escape_table_names(fresh_db):
+    # Restricted characters such as colon and dots should be escaped.
+    table = fresh_db["http://example.com"]
+    table.insert(search_records[0])
+    table.enable_fts(["text", "country"], fts_version="FTS4")
+    assert [] == table.search("trash pandas")
+    table.insert(search_records[1])
+    assert [] == table.search("trash pandas")
+    # Now run populate_fts to make this record available
+    table.populate_fts(["text", "country"])
+    assert [("racoons are trash pandas", "USA", "bar")] == table.search("usa")
+
+
 def test_optimize_fts(fresh_db):
     for fts_version in ("4", "5"):
         table_name = "searchable_{}".format(fts_version)
@@ -48,3 +81,14 @@ def test_optimize_fts(fresh_db):
         "searchable_5_fts",
     ):
         fresh_db[table_name].optimize()
+
+
+def test_enable_fts_w_triggers(fresh_db):
+    table = fresh_db["searchable"]
+    table.insert(search_records[0])
+    table.enable_fts(["text", "country"], fts_version="FTS4", create_triggers=True)
+    assert [("tanuki are tricksters", "Japan", "foo")] == table.search("tanuki")
+    table.insert(search_records[1])
+    # Triggers will auto-populate FTS virtual table, not need to call populate_fts()
+    assert [("racoons are trash pandas", "USA", "bar")] == table.search("usa")
+    assert [] == table.search("bar")