Decode JSON columns without changing table row values

Refs #3003

tests/test_api.py

@@ -775,6 +775,95 @@ test_json_columns_default_expected = [
 ]
 
 
+@pytest.mark.asyncio
+@pytest.mark.parametrize("endpoint", ["table", "query"])
+@pytest.mark.parametrize("include_columns", [False, True])
+@pytest.mark.parametrize(
+    "shape", ["objects", "object", "array", "arrayfirst", "arrays"]
+)
+async def test_json_columns_with_output_shapes(endpoint, include_columns, shape):
+    if endpoint == "query" and shape == "object":
+        pytest.skip("Object shape requires a table primary key")
+    ds = Datasette()
+    db = ds.add_memory_database("json_shapes")
+    await db.execute_write("CREATE TABLE t (value text, id integer primary key)")
+    await db.execute_write("INSERT INTO t VALUES (?, ?)", ['["a", "b"]', 1])
+    parameters = {"_json": "value", "_shape": shape}
+    if include_columns:
+        parameters["_extra"] = "columns"
+    if endpoint == "query":
+        parameters["sql"] = "SELECT value, id FROM t"
+        path = "/json_shapes/-/query.json"
+    else:
+        path = "/json_shapes/t.json"
+    try:
+        response = await ds.client.get(path + "?" + urllib.parse.urlencode(parameters))
+        assert response.status_code == 200
+        result = response.json()
+        row = {"value": ["a", "b"], "id": 1}
+        if shape == "object":
+            assert result == {"1": row}
+        elif shape == "array":
+            assert result == [row]
+        elif shape == "arrayfirst":
+            assert result == [["a", "b"]]
+        elif shape == "arrays":
+            assert result["rows"] == [[["a", "b"], 1]]
+        else:
+            assert result["rows"] == [row]
+        if shape in ("objects", "arrays"):
+            assert ("columns" in result) == include_columns
+    finally:
+        ds.close()
+
+
+@pytest.mark.asyncio
+@pytest.mark.parametrize("endpoint", ["table", "row"])
+@pytest.mark.parametrize(
+    "value,expected", [('["a"]', ["a"]), ("not JSON", "not JSON"), (None, None)]
+)
+async def test_json_columns_preserve_other_values(endpoint, value, expected):
+    ds = Datasette()
+    db = ds.add_memory_database("json_values")
+    await db.execute_write(
+        "CREATE TABLE t (id integer primary key, value text, other text)"
+    )
+    await db.execute_write(
+        "INSERT INTO t VALUES (?, ?, ?)", [1, value, '{"keep": true}']
+    )
+    path = "/json_values/t.json" if endpoint == "table" else "/json_values/t/1.json"
+    try:
+        response = await ds.client.get(path + "?_json=value")
+        assert response.status_code == 200
+        assert response.json()["rows"] == [
+            {"id": 1, "value": expected, "other": '{"keep": true}'}
+        ]
+    finally:
+        ds.close()
+
+
+@pytest.mark.asyncio
+@pytest.mark.parametrize(
+    "shape", ["objects", "object", "array", "arrayfirst", "arrays"]
+)
+async def test_json_columns_with_empty_results(shape):
+    ds = Datasette()
+    db = ds.add_memory_database("json_empty")
+    await db.execute_write("CREATE TABLE t (id integer primary key, value text)")
+    try:
+        response = await ds.client.get(f"/json_empty/t.json?_json=value&_shape={shape}")
+        assert response.status_code == 200
+        result = response.json()
+        if shape == "object":
+            assert result == {}
+        elif shape in ("array", "arrayfirst"):
+            assert result == []
+        else:
+            assert result["rows"] == []
+    finally:
+        ds.close()
+
+
 @pytest.mark.asyncio
 @pytest.mark.parametrize(
     "extra_args,expected",