From 742d46de0595027938d8bfea781f9bdf0f24f395 Mon Sep 17 00:00:00 2001
From: Simon Willison <swillison@gmail.com>
Date: Tue, 24 Feb 2026 15:22:05 -0800
Subject: [PATCH] v1 to v2 config migration with tests

Add _migrate_v1_to_v2() to convert aliases.json to config.json format.
Single-path-segment URLs are split into instance URL + default_database.
Auth keys are migrated from URLs to alias names. Original files are
backed up as .bak.

7 tests covering simple migration, no path segment, auth migration,
URL fallback for unmatched auth, skip if config exists, skip if no
aliases, and multi-path-segment URLs.

refs #29

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
---
 tests/test_migration.py | 116 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 116 insertions(+)
 create mode 100644 tests/test_migration.py

diff --git a/tests/test_migration.py b/tests/test_migration.py
new file mode 100644
index 0000000..2e81f03
--- /dev/null
+++ b/tests/test_migration.py
@@ -0,0 +1,116 @@
+"""Tests for v1 → v2 config migration."""
+
+from dclient.cli import _migrate_v1_to_v2
+import json
+import pathlib
+
+
+def test_migration_simple(tmpdir):
+    """Migrate a simple aliases.json with a database-in-URL alias."""
+    config_dir = pathlib.Path(tmpdir)
+    aliases_file = config_dir / "aliases.json"
+    aliases_file.write_text(
+        json.dumps({"content": "https://datasette.io/content"})
+    )
+
+    _migrate_v1_to_v2(config_dir)
+
+    config = json.loads((config_dir / "config.json").read_text())
+    assert config["instances"]["content"]["url"] == "https://datasette.io"
+    assert config["instances"]["content"]["default_database"] == "content"
+    assert config["default_instance"] is None
+
+    # Original should be renamed
+    assert (config_dir / "aliases.json.bak").exists()
+    assert not (config_dir / "aliases.json").exists()
+
+
+def test_migration_no_path_segment(tmpdir):
+    """Migrate an alias that has no database in the URL."""
+    config_dir = pathlib.Path(tmpdir)
+    aliases_file = config_dir / "aliases.json"
+    aliases_file.write_text(
+        json.dumps({"local": "http://localhost:8001"})
+    )
+
+    _migrate_v1_to_v2(config_dir)
+
+    config = json.loads((config_dir / "config.json").read_text())
+    assert config["instances"]["local"]["url"] == "http://localhost:8001"
+    assert config["instances"]["local"]["default_database"] is None
+
+
+def test_migration_with_auth(tmpdir):
+    """Auth keys are migrated from URLs to alias names."""
+    config_dir = pathlib.Path(tmpdir)
+    aliases_file = config_dir / "aliases.json"
+    aliases_file.write_text(
+        json.dumps({"content": "https://datasette.io/content"})
+    )
+    auth_file = config_dir / "auth.json"
+    auth_file.write_text(
+        json.dumps({"https://datasette.io/content": "tok123"})
+    )
+
+    _migrate_v1_to_v2(config_dir)
+
+    new_auths = json.loads((config_dir / "auth.json").read_text())
+    assert "content" in new_auths
+    assert new_auths["content"] == "tok123"
+
+    # Old auth should be backed up
+    assert (config_dir / "auth.json.bak").exists()
+
+
+def test_migration_auth_url_fallback(tmpdir):
+    """Auth entries without matching aliases are kept as URL keys."""
+    config_dir = pathlib.Path(tmpdir)
+    aliases_file = config_dir / "aliases.json"
+    aliases_file.write_text(json.dumps({}))
+    auth_file = config_dir / "auth.json"
+    auth_file.write_text(
+        json.dumps({"https://other.example.com": "tok456"})
+    )
+
+    _migrate_v1_to_v2(config_dir)
+
+    new_auths = json.loads((config_dir / "auth.json").read_text())
+    assert new_auths["https://other.example.com"] == "tok456"
+
+
+def test_migration_skips_if_config_exists(tmpdir):
+    """If config.json already exists, migration is skipped."""
+    config_dir = pathlib.Path(tmpdir)
+    (config_dir / "config.json").write_text(json.dumps({"existing": True}))
+    (config_dir / "aliases.json").write_text(json.dumps({"foo": "https://bar.com"}))
+
+    _migrate_v1_to_v2(config_dir)
+
+    # config.json should be untouched
+    assert json.loads((config_dir / "config.json").read_text()) == {"existing": True}
+    # aliases.json should NOT be renamed
+    assert (config_dir / "aliases.json").exists()
+
+
+def test_migration_skips_if_no_aliases(tmpdir):
+    """If aliases.json doesn't exist, migration is skipped."""
+    config_dir = pathlib.Path(tmpdir)
+
+    _migrate_v1_to_v2(config_dir)
+
+    assert not (config_dir / "config.json").exists()
+
+
+def test_migration_multi_path_segments(tmpdir):
+    """URL with multiple path segments stores URL as-is."""
+    config_dir = pathlib.Path(tmpdir)
+    aliases_file = config_dir / "aliases.json"
+    aliases_file.write_text(
+        json.dumps({"deep": "https://example.com/a/b/c"})
+    )
+
+    _migrate_v1_to_v2(config_dir)
+
+    config = json.loads((config_dir / "config.json").read_text())
+    assert config["instances"]["deep"]["url"] == "https://example.com/a/b/c"
+    assert config["instances"]["deep"]["default_database"] is None