1 files changed, 87 insertions, 0 deletions
diff --git a/tests/builder/equality.test.py b/tests/builder/equality.test.py
index 717d1ae..8482b51 100644
--- a/tests/builder/equality.test.py
+++ b/tests/builder/equality.test.py
@@ -1,6 +1,12 @@
 """Tests for value-based ``__eq__`` and ``__hash__`` on :class:`BuilderCore`."""
 
+import pytest
+
 from edify import Pattern, RegexBuilder
+from edify.errors.comparison import (
+    CannotCompareUnfinishedBuilderError,
+    CannotHashUnfinishedBuilderError,
+)
 
 
 def test_two_builders_with_the_same_chain_are_equal():
@@ -48,3 +54,84 @@ def test_hash_of_two_flags_that_differ_are_distinct():
     b = RegexBuilder().digit()
     assert a != b
     assert hash(a) != hash(b)
+
+
+def test_equality_uses_emitted_pattern_not_underlying_state():
+    from_chain = RegexBuilder().string("hi")
+    from_string_kwarg = RegexBuilder().string("hi")
+    assert from_chain.to_regex_string() == from_string_kwarg.to_regex_string()
+    assert from_chain == from_string_kwarg
+
+
+def test_hash_uses_emitted_pattern_and_flags_tuple():
+    a = RegexBuilder().string("hi")
+    b = RegexBuilder().string("hi")
+    assert hash(a) == hash((a.to_regex_string(), a._state.flags))
+    assert hash(a) == hash(b)
+
+
+def test_equality_raises_when_left_operand_has_open_frames():
+    left = RegexBuilder().any_of()
+    right = RegexBuilder().digit()
+    with pytest.raises(CannotCompareUnfinishedBuilderError):
+        _ = left == right
+
+
+def test_equality_raises_when_right_operand_has_open_frames():
+    left = RegexBuilder().digit()
+    right = RegexBuilder().any_of()
+    with pytest.raises(CannotCompareUnfinishedBuilderError):
+        _ = left == right
+
+
+def test_equality_raises_when_both_operands_are_unfinished():
+    left = RegexBuilder().any_of()
+    right = RegexBuilder().exactly(3)
+    with pytest.raises(CannotCompareUnfinishedBuilderError):
+        _ = left == right
+
+
+def test_hash_raises_when_frames_are_open():
+    with pytest.raises(CannotHashUnfinishedBuilderError):
+        hash(RegexBuilder().any_of())
+
+
+def test_equality_raises_when_a_quantifier_is_dangling():
+    left = RegexBuilder().exactly(3)
+    right = RegexBuilder().digit()
+    with pytest.raises(CannotCompareUnfinishedBuilderError):
+        _ = left == right
+
+
+def test_hash_raises_when_a_quantifier_is_dangling():
+    with pytest.raises(CannotHashUnfinishedBuilderError):
+        hash(RegexBuilder().exactly(3))
+
+
+def test_compare_error_message_names_the_open_frame():
+    with pytest.raises(CannotCompareUnfinishedBuilderError) as excinfo:
+        _ = RegexBuilder().named_capture("domain") == RegexBuilder().digit()
+    assert 'named_capture("domain")' in str(excinfo.value)
+    assert "frame opened here" in str(excinfo.value)
+    assert ".end()" in str(excinfo.value)
+
+
+def test_compare_error_message_names_the_dangling_quantifier():
+    with pytest.raises(CannotCompareUnfinishedBuilderError) as excinfo:
+        _ = RegexBuilder().digit() == RegexBuilder().exactly(4)
+    assert "exactly(4)" in str(excinfo.value)
+    assert "no element follows" in str(excinfo.value)
+    assert ".digit()" in str(excinfo.value)
+
+
+def test_hash_error_message_names_the_specific_problem():
+    with pytest.raises(CannotHashUnfinishedBuilderError) as excinfo:
+        hash(RegexBuilder().at_least(2))
+    assert "at_least(2)" in str(excinfo.value)
+
+
+def test_error_message_shows_a_source_pointer_when_called_from_user_code():
+    with pytest.raises(CannotHashUnfinishedBuilderError) as excinfo:
+        hash(RegexBuilder().any_of())
+    assert "-->" in str(excinfo.value)
+    assert __file__ in str(excinfo.value)