🐛 FIX: Exception when rendering CheckConstraints (#19)

Co-authored-by: Chris Sewell <chrisj_sewell@hotmail.com>

Author: Starbat

sphinx_sqlalchemy/main.py

@@ -11,6 +11,7 @@
 from sphinx.util.docutils import SphinxDirective
 from sqlalchemy import Column, Constraint, inspect
 from sqlalchemy.orm.mapper import Mapper
+from sqlalchemy.sql.elements import ClauseElement
 from sqlalchemy.sql.schema import (
     CheckConstraint,
     ForeignKeyConstraint,
@@ -169,6 +170,14 @@ def add_content(self, mapper: Mapper, definition: nodes.definition) -> None:
                 definition[-1] += nodes.list_item("", nodes.paragraph(text=text))
 
 
+def check_constraint_to_str(constraint: CheckConstraint) -> str:
+    if isinstance(constraint.sqltext, ClauseElement):
+        text = constraint.sqltext.compile(compile_kwargs={"literal_binds": True})
+    else:
+        text = getattr(constraint.sqltext, "text", "")
+    return f"CHECK ({text})"
+
+
 def contraint_to_str(constraint: Constraint) -> str:
     """Convert a constraint to a string."""
     if isinstance(constraint, PrimaryKeyConstraint):
@@ -182,7 +191,7 @@ def contraint_to_str(constraint: Constraint) -> str:
     if isinstance(constraint, UniqueConstraint):
         return f"UNIQUE ({', '.join(c.name for c in constraint.columns)})"
     if isinstance(constraint, CheckConstraint):
-        return f"CHECK ({constraint.sqltext.text})"  # type: ignore
+        return check_constraint_to_str(constraint)
     return "UNKNOWN"
 
 

tests/__snapshots__/test_basic.ambr

@@ -67,6 +67,9 @@
                   <rubric>
                       Constraints:
                   <bullet_list>
+                      <list_item>
+                          <paragraph>
+                              CHECK (length(trim('first_name')) > 0)
                       <list_item>
                           <paragraph>
                               PRIMARY KEY (pk)

tests/modules/module1.py

@@ -1,4 +1,4 @@
-from sqlalchemy import Column, UniqueConstraint, orm, types
+from sqlalchemy import CheckConstraint, Column, UniqueConstraint, func, orm, types
 
 Base = orm.declarative_base()
 
@@ -7,7 +7,12 @@ class TestUser(Base):
     """A ``user``."""
 
     __tablename__ = "dbusers"
-    __table_args__ = (UniqueConstraint("first_name", "last_name"),)
+    __table_args__ = (
+        UniqueConstraint("first_name", "last_name"),
+        CheckConstraint(
+            func.length(func.trim("first_name")) > 0, "check_project_has_name"
+        ),
+    )
     pk = Column(types.Integer, primary_key=True)
     first_name = Column(types.String, doc="The name of the user.")
     last_name = Column(types.String(255), doc="The surname of the user.")