From 66166505d6ecda3eb8b085676273544926b39246 Mon Sep 17 00:00:00 2001
From: Sergey Vasilyev <sergey.vasilyev@zalando.de>
Date: Tue, 23 Apr 2019 01:28:27 +0200
Subject: [PATCH] Test diffs calculation and manipulation

---
 tests/diffs/test_diff.py      | 78 +++++++++++++++++++++++++++++++++++
 tests/diffs/test_reduction.py | 54 ++++++++++++++++++++++++
 tests/diffs/test_resolving.py | 28 +++++++++++++
 3 files changed, 160 insertions(+)
 create mode 100644 tests/diffs/test_diff.py
 create mode 100644 tests/diffs/test_reduction.py
 create mode 100644 tests/diffs/test_resolving.py

diff --git a/tests/diffs/test_diff.py b/tests/diffs/test_diff.py
new file mode 100644
index 00000000..feec1232
--- /dev/null
+++ b/tests/diffs/test_diff.py
@@ -0,0 +1,78 @@
+from kopf.structs.diffs import diff
+
+
+def test_scalars_equal():
+    a = 100
+    b = 100
+    d = diff(a, b)
+    assert d == ()
+
+
+def test_scalars_unequal():
+    a = 100
+    b = 200
+    d = diff(a, b)
+    assert d == (('change', (), 100, 200),)
+
+
+def test_strings_equal():
+    a = 'hello'
+    b = 'hello'
+    d = diff(a, b)
+    assert d == ()
+
+
+def test_strings_unequal():
+    a = 'hello'
+    b = 'world'
+    d = diff(a, b)
+    assert d == (('change', (), 'hello', 'world'),)
+
+
+def test_lists_equal():
+    a = [100, 200, 300]
+    b = [100, 200, 300]
+    d = diff(a, b)
+    assert d == ()
+
+
+def test_lists_unequal():
+    a = [100, 200, 300]
+    b = [100, 666, 300]
+    d = diff(a, b)
+    assert d == (('change', (), [100, 200, 300], [100, 666, 300]),)
+
+
+def test_dicts_equal():
+    a = {'hello': 'world', 'key': 'val'}
+    b = {'key': 'val', 'hello': 'world'}
+    d = diff(a, b)
+    assert d == ()
+
+
+def test_dicts_with_keys_added():
+    a = {'hello': 'world'}
+    b = {'hello': 'world', 'key': 'val'}
+    d = diff(a, b)
+    assert d == (('add', ('key',), None, 'val'),)
+
+
+def test_dicts_with_keys_removed():
+    a = {'hello': 'world', 'key': 'val'}
+    b = {'hello': 'world'}
+    d = diff(a, b)
+    assert d == (('remove', ('key',), 'val', None),)
+
+
+def test_dicts_with_keys_changed():
+    a = {'hello': 'world', 'key': 'old'}
+    b = {'hello': 'world', 'key': 'new'}
+    d = diff(a, b)
+    assert d == (('change', ('key',), 'old', 'new'),)
+
+
+def test_dicts_with_subkeys_changed():
+    a = {'main': {'hello': 'world', 'key': 'old'}}
+    b = {'main': {'hello': 'world', 'key': 'new'}}
+    d = diff(a, b)
+    assert d == (('change', ('main', 'key'), 'old', 'new'),)
diff --git a/tests/diffs/test_reduction.py b/tests/diffs/test_reduction.py
new file mode 100644
index 00000000..d38f2ec0
--- /dev/null
+++ b/tests/diffs/test_reduction.py
@@ -0,0 +1,54 @@
+import pytest
+
+from kopf.structs.diffs import reduce
+
+
+DIFF = (
+    ('op'    , (), 'old', 'new'),  # unknown operations should be passed through
+    ('add'   , ('key1',), None, 'new1'),
+    ('change', ('key2',), 'old2', 'new2'),
+    ('add'   , ('key2', 'suba'), 'olda', 'newa'),
+    ('remove', ('key2', 'subb'), 'oldb', 'newb'),
+    ('remove', ('key3',), 'old3', None),
+)
+
+
+@pytest.mark.parametrize('diff', [
+    [['op', ['key', 'sub'], 'old', 'new']],
+    [['op', ('key', 'sub'), 'old', 'new']],
+    [('op', ['key', 'sub'], 'old', 'new')],
+    [('op', ('key', 'sub'), 'old', 'new')],
+    (['op', ['key', 'sub'], 'old', 'new'],),
+    (['op', ('key', 'sub'), 'old', 'new'],),
+    (('op', ['key', 'sub'], 'old', 'new'),),
+    (('op', ('key', 'sub'), 'old', 'new'),),
+], ids=[
+    'lll-diff', 'llt-diff', 'ltl-diff', 'ltt-diff',
+    'tll-diff', 'tlt-diff', 'ttl-diff', 'ttt-diff',
+])
+@pytest.mark.parametrize('path', [
+    ['key', 'sub'],
+    ('key', 'sub'),
+], ids=['list-path', 'tuple-path'])
+def test_type_ignored_for_inputs_but_is_tuple_for_output(diff, path):
+    result = reduce(diff, path)
+    assert result == (('op', (), 'old', 'new'),)
+
+
+def test_empty_path_selects_all_ops():
+    result = reduce(DIFF, [])
+    assert result == DIFF
+
+
+def test_existent_path_selects_relevant_ops():
+    result = reduce(DIFF, ['key2'])
+    assert result == (
+        ('change', (), 'old2', 'new2'),
+        ('add'   , ('suba',), 'olda', 'newa'),
+        ('remove', ('subb',), 'oldb', 'newb'),
+    )
+
+
+def test_nonexistent_path_selects_nothing():
+    result = reduce(DIFF, ['nonexistent-key'])
+    assert result == ()
diff --git a/tests/diffs/test_resolving.py b/tests/diffs/test_resolving.py
new file mode 100644
index 00000000..bc7426d3
--- /dev/null
+++ b/tests/diffs/test_resolving.py
@@ -0,0 +1,28 @@
+import pytest
+
+from kopf.structs.diffs import resolve
+
+
+def test_existing_key():
+    d = {'abc': {'def': {'hij': 'val'}}}
+    r = resolve(d, ['abc', 'def', 'hij'])
+    assert r == 'val'
+
+
+def test_unexisting_key():
+    d = {'abc': {'def': {'hij': 'val'}}}
+    with pytest.raises(KeyError):
+        resolve(d, ['abc', 'def', 'xyz'])
+
+
+def test_nonmapping_key():
+    d = {'key': 'val'}
+    with pytest.raises(TypeError):
+        resolve(d, ['key', 'sub'])
+
+
+def test_empty_path():
+    d = {'key': 'val'}
+    r = resolve(d, [])
+    assert r == d
+    assert r is d