Support postgres:// scheme

Author: Kareem Zidane

.github/workflows/main.yml

@@ -26,18 +26,14 @@ jobs:
         python-version: '3.6'
     - name: Setup databases
       run: |
-        python setup.py install
-        pip install mysqlclient
-        pip install psycopg2-binary
-        touch test.db test1.db
+        pip install .
+        pip install mysqlclient psycopg2-binary
     - name: Run tests
       run: python tests/sql.py
     - name: Install pypa/build
-      run: |
-        python -m pip install build --user
+      run: python -m pip install build --user
     - name: Build a binary wheel and a source tarball
-      run: |
-        python -m build --sdist --wheel --outdir dist/ .
+      run: python -m build --sdist --wheel --outdir dist/ .
     - name: Deploy to PyPI
       if: ${{ github.ref == 'refs/heads/main' }}
       uses: pypa/gh-action-pypi-publish@release/v1

.gitignore

@@ -5,5 +5,6 @@
 *.db
 *.egg-info/
 *.pyc
+build/
 dist/
 test.db

src/cs50/_engine.py

@@ -1,4 +1,5 @@
 import threading
+import warnings
 
 from ._engine_util import create_engine
 
@@ -11,6 +12,7 @@ class Engine:
     """
 
     def __init__(self, url):
+        url = _replace_scheme_if_postgres(url)
         self._engine = create_engine(url)
 
     def get_transaction_connection(self):
@@ -64,3 +66,23 @@ def _thread_local_connections():
         connections = thread_local_data.connections = {}
 
     return connections
+
+def _replace_scheme_if_postgres(url):
+    """
+    Replaces the postgres scheme with the postgresql scheme if possible since the postgres scheme
+    is deprecated.
+
+    :returns: url with postgresql scheme if the scheme was postgres; otherwise returns url as is
+    """
+
+    if url.startswith("postgres://"):
+        with warnings.catch_warnings():
+            warnings.simplefilter("always")
+            warnings.warn(
+                "The postgres:// scheme is deprecated and will not be supported in the next major"
+                    + " release of the library. Please use the postgresql:// scheme instead.",
+                DeprecationWarning
+            )
+        url = f"postgresql{url[len('postgres'):]}"
+
+    return url

tests/sql.py

@@ -169,6 +169,9 @@ def setUp(self):
     def test_cte(self):
         self.assertEqual(self.db.execute("WITH foo AS ( SELECT 1 AS bar ) SELECT bar FROM foo"), [{"bar": 1}])
 
+    def test_postgres_scheme(self):
+        db = SQL("postgres://postgres:postgres@127.0.0.1/test")
+        db.execute("SELECT 1")
 
 class SQLiteTests(SQLTests):