Add tests for rewrite plugin

test/plugins/test_rewrite.py

@@ -0,0 +1,67 @@
+import pytest
+
+from beets.test.helper import PluginTestCase
+from beets.ui import UserError
+from beetsplug.rewrite import RewritePlugin
+
+
+class RewritePluginTest(PluginTestCase):
+    plugin = "rewrite"
+    preload_plugin = False
+
+    def test_artist_rewrite_applies_to_artist_albumartist_and_album_fields(
+        self,
+    ):
+        with self.configure_plugin({"artist .*jimi hendrix.*": "Jimi Hendrix"}):
+            item = self.add_item(
+                artist="The Jimi Hendrix Experience",
+                albumartist="The Jimi Hendrix Experience",
+            )
+            album = self.lib.add_album([item])
+
+            assert item.artist == "Jimi Hendrix"
+            assert item.albumartist == "Jimi Hendrix"
+            assert album.evaluate_template("$albumartist") == "Jimi Hendrix"
+
+    def test_rewrite_uses_first_matching_rule(self):
+        with self.configure_plugin(
+            {
+                "artist .*hendrix.*": "Hendrix catalog",
+                "artist the jimi hendrix experience": "Experience catalog",
+            }
+        ):
+            item = self.add_item(
+                artist="The Jimi Hendrix Experience",
+                albumartist="The Jimi Hendrix Experience",
+            )
+
+            assert item.artist == "Hendrix catalog"
+
+    def test_rewrite_is_case_insensitive_and_leaves_non_matches_unchanged(
+        self,
+    ):
+        with self.configure_plugin(
+            {"artist odd eye circle": "LOONA / ODD EYE CIRCLE"}
+        ):
+            matching_item = self.add_item(
+                artist="ODD EYE CIRCLE",
+                albumartist="ODD EYE CIRCLE",
+            )
+            other_item = self.add_item(artist="ARTMS", albumartist="ARTMS")
+
+            assert matching_item.artist == "LOONA / ODD EYE CIRCLE"
+            assert other_item.artist == "ARTMS"
+
+    def test_invalid_rewrite_spec_raises_user_error(self):
+        self.config[self.plugin].set({"artist": "Jimi Hendrix"})
+
+        with pytest.raises(UserError, match="invalid rewrite specification"):
+            RewritePlugin()
+
+    def test_invalid_field_name_raises_user_error(self):
+        self.config[self.plugin].set({"not_a_field rock": "Classic Rock"})
+
+        with pytest.raises(
+            UserError, match="invalid field name \\(not_a_field\\) in rewriter"
+        ):
+            RewritePlugin()