Fix autocompletion on sqlite FTS backend

* Fix incorrect signatures for `SQLiteAutocompleteQueryCompiler`
* Syntax for an autocomplete search should have the `*` outside of quotes - `"foo"*` rather than `"foo*"`
* Query compiler was hardcoded to search on the 'title' and 'body' fields of the FTS table, rather than 'autocomplete'

Full support for searching on specified fields is still lacking - the 'title' and 'body' fields are special cased, and other column names will return a SQL error.

wagtail/search/backends/database/sqlite/query.py

@@ -71,16 +71,12 @@ def __init__(self, value, output_field=None, *, prefix=False, weight=None):
         super().__init__(value, output_field=output_field)
 
     def as_sql(self, compiler, connection):
-        param = "%s" % self.value.replace("'", "''").replace("\\", "\\\\")
+        param = self.value.replace("'", "''").replace("\\", "\\\\")
 
-        template = '"%s"'
-
-        label = ""
         if self.prefix:
-            label += "*"
-
-        if label:
-            param = "{}{}".format(param, label)
+            template = '"%s"*'
+        else:
+            template = '"%s"'
 
         return template, [param]
 

wagtail/search/backends/database/sqlite/sqlite.py

@@ -316,6 +316,7 @@ class SQLiteSearchQueryCompiler(BaseSearchQueryCompiler):
     DEFAULT_OPERATOR = "AND"
     LAST_TERM_IS_PREFIX = False
     TARGET_SEARCH_FIELD_TYPE = SearchField
+    FTS_TABLE_FIELDS = ["title", "body"]
 
     def __init__(self, *args, **kwargs):
         super().__init__(*args, **kwargs)
@@ -516,7 +517,7 @@ def search(self, config, start, stop, score_field=None):
             )  # We add the subsequent vectors to the combined vector.
 
         # Build the FTS match expression.
-        expr = MatchExpression(self.fields or ["title", "body"], search_query)
+        expr = MatchExpression(self.fields or self.FTS_TABLE_FIELDS, search_query)
         # Perform the FTS search. We'll get entries in the SQLiteFTSIndexEntry model.
         objs = (
             SQLiteFTSIndexEntry.objects.filter(expr)
@@ -589,19 +590,17 @@ def _connect_filters(self, filters, connector, negated):
 class SQLiteAutocompleteQueryCompiler(SQLiteSearchQueryCompiler):
     LAST_TERM_IS_PREFIX = True
     TARGET_SEARCH_FIELD_TYPE = AutocompleteField
+    FTS_TABLE_FIELDS = ["autocomplete"]
 
     def get_config(self, backend):
         return backend.autocomplete_config
 
     def get_search_fields_for_model(self):
         return self.queryset.model.get_autocomplete_search_fields()
 
-    def get_index_vectors(self, search_query):
+    def get_index_vectors(self):
         return [(F("index_entries__autocomplete"), 1.0)]
 
-    def get_fields_vectors(self, search_query):
-        raise NotImplementedError()
-
 
 class SQLiteSearchResults(BaseSearchResults):
     def get_queryset(self, for_count=False):
@@ -656,10 +655,7 @@ def facet(self, field_name):
 
 class SQLiteSearchBackend(BaseSearchBackend):
     query_compiler_class = SQLiteSearchQueryCompiler
-
-    # FIXME: the implementation of SQLiteAutocompleteQueryCompiler is incomplete -
-    # leave this undefined so that we get a clean NotImplementedError from BaseSearchBackend
-    # autocomplete_query_compiler_class = SQLiteAutocompleteQueryCompiler
+    autocomplete_query_compiler_class = SQLiteAutocompleteQueryCompiler
 
     results_class = SQLiteSearchResults
     rebuilder_class = SQLiteSearchRebuilder
@@ -668,7 +664,10 @@ class SQLiteSearchBackend(BaseSearchBackend):
     def __init__(self, params):
         super().__init__(params)
         self.index_name = params.get("INDEX", "default")
-        self.config = params.get("SEARCH_CONFIG")
+
+        # SQLite backend currently has no config options
+        self.config = None
+        self.autocomplete_config = None
 
         if params.get("ATOMIC_REBUILD", False):
             self.rebuilder_class = self.atomic_rebuilder_class

wagtail/search/tests/test_sqlite_backend.py

@@ -8,7 +8,6 @@
 
 from wagtail.search.backends.database.sqlite.utils import fts5_available
 from wagtail.search.tests.test_backends import BackendTests
-from wagtail.test.search import models
 
 
 @unittest.skipUnless(
@@ -44,23 +43,7 @@ def test_annotate_score(self):
     def test_annotate_score_with_slice(self):
         return super().test_annotate_score_with_slice()
 
-    def test_autocomplete_raises_not_implemented_error(self):
-        with self.assertRaises(NotImplementedError):
-            self.backend.autocomplete("Py", models.Book)
-
-    @skip("The SQLite backend doesn't support autocomplete.")
-    def test_autocomplete(self):
-        return super().test_autocomplete()
-
-    @skip("The SQLite backend doesn't support autocomplete.")
-    def test_autocomplete_not_affected_by_stemming(self):
-        return super().test_autocomplete_not_affected_by_stemming()
-
-    @skip("The SQLite backend doesn't support autocomplete.")
-    def test_autocomplete_uses_autocompletefield(self):
-        return super().test_autocomplete_uses_autocompletefield()
-
-    @skip("The SQLite backend doesn't support autocomplete.")
+    @skip("The SQLite backend doesn't support searching on specified fields.")
     def test_autocomplete_with_fields_arg(self):
         return super().test_autocomplete_with_fields_arg()