fix: empty OR operand guard, LIKE error message, README negation typo

- Raise ValueError for empty OR operands ('laptop OR ', ' OR tablet')
  instead of crashing with IndexError
- LIKE error message now says 'LIKE can only be used...' instead of
  'like() can only be used...' since LIKE is not a function
- Fix README table: negation of single-term FULLTEXT doesn't have parens
- Add 2 new tests (370 total)

Author: nkanu17

README.md

@@ -187,7 +187,7 @@ Full-text search on TEXT fields with multiple search modes:
 | Proximity + order | `fulltext(title, 'gaming laptop', 2, true)` | `@title:(gaming laptop) => { $slop: 2; $inorder: true; }` |
 | Optional term | `fulltext(title, 'laptop ~gaming')` | `@title:(laptop ~gaming)` |
 | BM25 score | `SELECT score() AS relevance FROM idx` | `FT.SEARCH ... WITHSCORES` |
-| Negation | `NOT fulltext(title, 'refurbished')` | `-@title:(refurbished)` |
+| Negation | `NOT fulltext(title, 'refurbished')` | `-@title:refurbished` |
 
 **Examples:**
 

sql_redis/query_builder.py

@@ -148,6 +148,11 @@ def build_text_condition(
             or_parts: list[str] = []
             for part in re.split(r"\s+[Oo][Rr]\s+", value):
                 words = part.strip().split()
+                if not words:
+                    raise ValueError(
+                        "Empty operand in OR expression — each side of OR "
+                        "must contain at least one search term."
+                    )
                 if len(words) > 1:
                     escaped = " ".join(self._escape_fulltext_term(w) for w in words)
                     or_parts.append(f"({escaped})")

sql_redis/translator.py

@@ -197,8 +197,13 @@ def _build_condition(self, condition: Condition, field_type: str | None) -> str:
         # only make sense for TEXT fields; silently falling through to TAG/NUMERIC
         # would produce incorrect queries.
         if condition.operator in ("FUZZY", "FULLTEXT", "LIKE") and field_type != "TEXT":
+            op_display = (
+                "LIKE"
+                if condition.operator == "LIKE"
+                else f"{condition.operator.lower()}()"
+            )
             raise ValueError(
-                f"{condition.operator.lower()}() can only be used on TEXT fields, "
+                f"{op_display} can only be used on TEXT fields, "
                 f"but '{condition.field}' is {field_type or 'unknown'}."
             )
 

tests/test_query_builder.py

@@ -678,3 +678,15 @@ def test_or_both_multiword_operands_grouped(self):
             "title", "FULLTEXT", "gaming laptop OR android tablet"
         )
         assert result == "@title:((gaming laptop)|(android tablet))"
+
+    def test_or_trailing_empty_operand_raises(self):
+        """Trailing OR with empty operand raises ValueError."""
+        builder = QueryBuilder()
+        with pytest.raises(ValueError, match="Empty operand in OR expression"):
+            builder.build_text_condition("title", "FULLTEXT", "laptop OR ")
+
+    def test_or_leading_empty_operand_raises(self):
+        """Leading OR with empty operand raises ValueError."""
+        builder = QueryBuilder()
+        with pytest.raises(ValueError, match="Empty operand in OR expression"):
+            builder.build_text_condition("title", "FULLTEXT", " OR tablet")