feat: basic support for displaying version history

this is not terribly feature-rich yet, just the basics

tests/test_diffs.py

@@ -0,0 +1,222 @@
+# -*- coding: utf-8; -*-
+
+from wuttaweb import diffs as mod
+from wuttaweb.testing import WebTestCase, VersionWebTestCase
+
+
+# nb. using WebTestCase here only for mako support in render_html()
+class TestDiff(WebTestCase):
+
+    def make_diff(self, *args, **kwargs):
+        return mod.Diff(*args, **kwargs)
+
+    def test_constructor(self):
+        old_data = {"foo": "bar"}
+        new_data = {"foo": "baz"}
+        diff = self.make_diff(old_data, new_data, fields=["foo"])
+        self.assertEqual(diff.fields, ["foo"])
+
+    def test_make_fields(self):
+        old_data = {"foo": "bar"}
+        new_data = {"foo": "bar", "baz": "zer"}
+        # nb. this calls make_fields()
+        diff = self.make_diff(old_data, new_data)
+        # TODO: should the fields be cumulative? or just use new_data?
+        self.assertEqual(diff.fields, ["baz", "foo"])
+
+    def test_values(self):
+        old_data = {"foo": "bar"}
+        new_data = {"foo": "baz"}
+        diff = self.make_diff(old_data, new_data)
+        self.assertEqual(diff.old_value("foo"), "bar")
+        self.assertEqual(diff.new_value("foo"), "baz")
+
+    def test_values_differ(self):
+        old_data = {"foo": "bar"}
+        new_data = {"foo": "baz"}
+        diff = self.make_diff(old_data, new_data)
+        self.assertTrue(diff.values_differ("foo"))
+
+        old_data = {"foo": "bar"}
+        new_data = {"foo": "bar"}
+        diff = self.make_diff(old_data, new_data)
+        self.assertFalse(diff.values_differ("foo"))
+
+    def test_render_values(self):
+        old_data = {"foo": "bar"}
+        new_data = {"foo": "baz"}
+        diff = self.make_diff(old_data, new_data)
+        self.assertEqual(diff.render_old_value("foo"), "'bar'")
+        self.assertEqual(diff.render_new_value("foo"), "'baz'")
+
+    def test_get_old_value_attrs(self):
+
+        # no change
+        old_data = {"foo": "bar"}
+        new_data = {"foo": "bar"}
+        diff = self.make_diff(old_data, new_data, nature="update")
+        self.assertEqual(diff.get_old_value_attrs(False), {})
+
+        # update
+        old_data = {"foo": "bar"}
+        new_data = {"foo": "baz"}
+        diff = self.make_diff(old_data, new_data, nature="update")
+        self.assertEqual(
+            diff.get_old_value_attrs(True),
+            {"style": f"background-color: {diff.old_color};"},
+        )
+
+        # delete
+        old_data = {"foo": "bar"}
+        new_data = {}
+        diff = self.make_diff(old_data, new_data, nature="delete")
+        self.assertEqual(
+            diff.get_old_value_attrs(True),
+            {"style": f"background-color: {diff.old_color};"},
+        )
+
+    def test_get_new_value_attrs(self):
+
+        # no change
+        old_data = {"foo": "bar"}
+        new_data = {"foo": "bar"}
+        diff = self.make_diff(old_data, new_data, nature="update")
+        self.assertEqual(diff.get_new_value_attrs(False), {})
+
+        # update
+        old_data = {"foo": "bar"}
+        new_data = {"foo": "baz"}
+        diff = self.make_diff(old_data, new_data, nature="update")
+        self.assertEqual(
+            diff.get_new_value_attrs(True),
+            {"style": f"background-color: {diff.new_color};"},
+        )
+
+        # create
+        old_data = {}
+        new_data = {"foo": "bar"}
+        diff = self.make_diff(old_data, new_data, nature="create")
+        self.assertEqual(
+            diff.get_new_value_attrs(True),
+            {"style": f"background-color: {diff.new_color};"},
+        )
+
+    def test_render_field_row(self):
+        old_data = {"foo": "bar"}
+        new_data = {"foo": "baz"}
+        diff = self.make_diff(old_data, new_data)
+        row = diff.render_field_row("foo")
+        self.assertIn("<tr>", row)
+        self.assertIn("&#39;bar&#39;", row)
+        self.assertIn(f'style="background-color: {diff.old_color};"', row)
+        self.assertIn("&#39;baz&#39;", row)
+        self.assertIn(f'style="background-color: {diff.new_color};"', row)
+        self.assertIn("</tr>", row)
+
+    def test_render_html(self):
+        old_data = {"foo": "bar"}
+        new_data = {"foo": "baz"}
+        diff = self.make_diff(old_data, new_data)
+        html = diff.render_html()
+        self.assertIn("<table", html)
+        self.assertIn("<tr>", html)
+        self.assertIn("&#39;bar&#39;", html)
+        self.assertIn(f'style="background-color: {diff.old_color};"', html)
+        self.assertIn("&#39;baz&#39;", html)
+        self.assertIn(f'style="background-color: {diff.new_color};"', html)
+        self.assertIn("</tr>", html)
+        self.assertIn("</table>", html)
+
+
+class TestVersionDiff(VersionWebTestCase):
+
+    def make_diff(self, *args, **kwargs):
+        return mod.VersionDiff(*args, **kwargs)
+
+    def test_constructor(self):
+        import sqlalchemy_continuum as continuum
+
+        model = self.app.model
+        user = model.User(username="fred")
+        self.session.add(user)
+        self.session.commit()
+        user.username = "freddie"
+        self.session.commit()
+        self.session.delete(user)
+        self.session.commit()
+
+        txncls = continuum.transaction_class(model.User)
+        vercls = continuum.version_class(model.User)
+        versions = self.session.query(vercls).order_by(vercls.transaction_id).all()
+        self.assertEqual(len(versions), 3)
+
+        version = versions[0]
+        diff = self.make_diff(version)
+        self.assertEqual(diff.nature, "create")
+        self.assertEqual(
+            diff.fields,
+            ["active", "password", "person_uuid", "prevent_edit", "username", "uuid"],
+        )
+
+        version = versions[1]
+        diff = self.make_diff(version)
+        self.assertEqual(diff.nature, "update")
+        self.assertEqual(
+            diff.fields,
+            ["active", "password", "person_uuid", "prevent_edit", "username", "uuid"],
+        )
+
+        version = versions[2]
+        diff = self.make_diff(version)
+        self.assertEqual(diff.nature, "delete")
+        self.assertEqual(
+            diff.fields,
+            ["active", "password", "person_uuid", "prevent_edit", "username", "uuid"],
+        )
+
+    def test_render_values(self):
+        import sqlalchemy_continuum as continuum
+
+        model = self.app.model
+        user = model.User(username="fred")
+        self.session.add(user)
+        self.session.commit()
+        user.username = "freddie"
+        self.session.commit()
+        self.session.delete(user)
+        self.session.commit()
+
+        txncls = continuum.transaction_class(model.User)
+        vercls = continuum.version_class(model.User)
+        versions = self.session.query(vercls).order_by(vercls.transaction_id).all()
+        self.assertEqual(len(versions), 3)
+
+        version = versions[0]
+        diff = self.make_diff(version)
+        self.assertEqual(diff.nature, "create")
+        self.assertEqual(diff.render_old_value("username"), "")
+        self.assertEqual(
+            diff.render_new_value("username"),
+            '<span style="font-family: monospace;">&#39;fred&#39;</span>',
+        )
+
+        version = versions[1]
+        diff = self.make_diff(version)
+        self.assertEqual(diff.nature, "update")
+        self.assertEqual(
+            diff.render_old_value("username"),
+            '<span style="font-family: monospace;">&#39;fred&#39;</span>',
+        )
+        self.assertEqual(
+            diff.render_new_value("username"),
+            '<span style="font-family: monospace;">&#39;freddie&#39;</span>',
+        )
+
+        version = versions[2]
+        diff = self.make_diff(version)
+        self.assertEqual(diff.nature, "delete")
+        self.assertEqual(
+            diff.render_old_value("username"),
+            '<span style="font-family: monospace;">&#39;freddie&#39;</span>',
+        )
+        self.assertEqual(diff.render_new_value("username"), "")