confirm: true mechanism for drop table API, closes #1887

datasette/views/special.py

@@ -336,7 +336,7 @@ class ApiExplorerView(BaseView):
                         {
                             "path": self.ds.urls.table(name, table) + "/-/drop",
                             "label": "Drop table {}".format(table),
-                            "json": {},
+                            "json": {"confirm": False},
                             "method": "POST",
                         }
                     )

datasette/views/table.py

@@ -1236,6 +1236,26 @@ class TableDropView(BaseView):
             request.actor, "drop-table", resource=(database_name, table_name)
         ):
             return _error(["Permission denied"], 403)
+
+        confirm = False
+        try:
+            data = json.loads(await request.post_body())
+            confirm = data.get("confirm")
+        except json.JSONDecodeError as e:
+            pass
+
+        if not confirm:
+            return Response.json(
+                {
+                    "ok": True,
+                    "row_count": (
+                        await db.execute("select count(*) from [{}]".format(table_name))
+                    ).single_value(),
+                    "message": 'Pass "confirm": true to confirm',
+                },
+                status=200,
+            )
+
         # Drop table
         def drop_table(conn):
             sqlite_utils.Database(conn)[table_name].drop()

docs/json_api.rst

@@ -572,6 +572,24 @@ To drop a table, make a ``POST`` to ``/<database>/<table>/-/drop``. This require
     Content-Type: application/json
     Authorization: Bearer dstok_<rest-of-token>
 
-If successful, this will return a ``200`` status code and a ``{"ok": true}`` response body.
+Without a POST body this will return a status ``200`` with a note about how many rows will be deleted:
+
+.. code-block:: json
+
+    {
+        "ok": true,
+        "row_count": 5,
+        "message": "Pass \"confirm\": true to confirm"
+    }
+
+If you pass the following POST body:
+
+.. code-block:: json
+
+    {
+        "confirm": true
+    }
+
+Then the table will be dropped and a status ``200`` response of ``{"ok": true}`` will be returned.
 
 Any errors will return ``{"errors": ["... descriptive message ..."], "ok": false}``, and a ``400`` status code for a bad input or a ``403`` status code for an authentication or permission error.

tests/test_api_write.py

@@ -348,7 +348,9 @@ async def test_drop_table(ds_write, scenario):
     else:
         token = write_token(ds_write)
     should_work = scenario == "has_perm"
-
+    await ds_write.get_database("data").execute_write(
+        "insert into docs (id, title) values (1, 'Row 1')"
+    )
     path = "/data/{}/-/drop".format("docs" if scenario != "bad_table" else "bad_table")
     response = await ds_write.client.post(
         path,
@@ -357,11 +359,7 @@ async def test_drop_table(ds_write, scenario):
             "Content-Type": "application/json",
         },
     )
-    if should_work:
-        assert response.status_code == 200
-        assert response.json() == {"ok": True}
-        assert (await ds_write.client.get("/data/docs")).status_code == 404
-    else:
+    if not should_work:
         assert (
             response.status_code == 403
             if scenario in ("no_token", "bad_token")
@@ -374,3 +372,23 @@ async def test_drop_table(ds_write, scenario):
             else ["Table not found: bad_table"]
         )
         assert (await ds_write.client.get("/data/docs")).status_code == 200
+    else:
+        # It should show a confirmation page
+        assert response.status_code == 200
+        assert response.json() == {
+            "ok": True,
+            "row_count": 1,
+            "message": 'Pass "confirm": true to confirm',
+        }
+        assert (await ds_write.client.get("/data/docs")).status_code == 200
+        # Now send confirm: true
+        response2 = await ds_write.client.post(
+            path,
+            json={"confirm": True},
+            headers={
+                "Authorization": "Bearer {}".format(token),
+                "Content-Type": "application/json",
+            },
+        )
+        assert response2.json() == {"ok": True}
+        assert (await ds_write.client.get("/data/docs")).status_code == 404