From 7c8f8aa209e4ba7bf83976f8495d67c28fbfca24 Mon Sep 17 00:00:00 2001
From: Simon Willison <swillison@gmail.com>
Date: Fri, 17 Dec 2021 18:19:36 -0800
Subject: [PATCH] Documentation for Datasette() constructor, closes #1563

---
 docs/internals.rst                | 21 +++++++++++++++++++++
 tests/test_internals_datasette.py |  2 +-
 2 files changed, 22 insertions(+), 1 deletion(-)

diff --git a/docs/internals.rst b/docs/internals.rst
index 411327eb..c706031b 100644
--- a/docs/internals.rst
+++ b/docs/internals.rst
@@ -196,6 +196,27 @@ Datasette class
 
 This object is an instance of the ``Datasette`` class, passed to many plugin hooks as an argument called ``datasette``.
 
+You can create your own instance of this - for example to help write tests for a plugin - like so:
+
+.. code-block:: python
+
+    from datasette.app import Datasette
+
+    # With no arguments a single in-memory database will be attached
+    datasette = Datasette()
+
+    # The files= argument can load files from disk
+    datasette = Datasette(files="/path/to/my-database.db")
+
+    # Pass metadata as a JSON dictionary like this
+    datasette = Datasette(files="/path/to/my-database.db", metadata={
+        "databases": {
+            "my-database": {
+                "description": "This is my database"
+            }
+        }
+    })
+
 .. _datasette_databases:
 
 .databases
diff --git a/tests/test_internals_datasette.py b/tests/test_internals_datasette.py
index 692312a7..adf84be9 100644
--- a/tests/test_internals_datasette.py
+++ b/tests/test_internals_datasette.py
@@ -50,7 +50,7 @@ def test_datasette_setting(datasette, setting, expected):
 
 @pytest.mark.asyncio
 async def test_datasette_constructor():
-    ds = Datasette(memory=True)
+    ds = Datasette()
     databases = (await ds.client.get("/-/databases.json")).json()
     assert databases == [
         {