add simple test for merging in MergeInputReader

Author: lonvia

test/test_merge_input_reader.py

@@ -0,0 +1,101 @@
+# SPDX-License-Identifier: BSD-2-Clause
+#
+# This file is part of pyosmium. (https://osmcode.org/pyosmium/)
+#
+# Copyright (C) 2026 Sarah Hoffmann <lonvia@denofr.de> and others.
+# For a full list of authors see the git log.
+from textwrap import dedent
+import uuid
+
+import pytest
+
+import osmium
+
+
+class ListHandler:
+    def __init__(self):
+        self.data = []
+
+    def node(self, o):
+        self.data.append(f"N{o.id}/{o.version}")
+
+    def way(self, o):
+        self.data.append(f"W{o.id}/{o.version}")
+
+    def relation(self, o):
+        self.data.append(f"R{o.id}/{o.version}")
+
+    def area(self, _):
+        assert not "Area handler should not be called"
+
+
+def add_as_buffer(mir, opl, tmp_path):
+    mir.add_buffer(dedent(opl).encode('utf-8'), format='opl')
+
+
+def add_as_file(mir, opl, tmp_path):
+    fn = tmp_path / (str(uuid.uuid4()) + '.opl')
+    fn.write_text(dedent(opl))
+
+    mir.add_file(str(fn))
+
+
+@pytest.mark.parametrize('adder', [add_as_buffer, add_as_file])
+def test_simple_input(adder, tmp_path):
+    mir = osmium.MergeInputReader()
+
+    opl = """\
+        n1 v1 x1 y1
+        w3 v34 Nn1
+        """
+
+    adder(mir, opl, tmp_path)
+
+    h = ListHandler()
+    mir.apply(h)
+
+    assert h.data == ['N1/1', 'W3/34']
+
+
+@pytest.mark.parametrize('adder', [add_as_buffer, add_as_file])
+def test_multibuffer_no_simplify(adder, tmp_path):
+    mir = osmium.MergeInputReader()
+
+    opls = ["""\
+            n1 v1 x1 y1
+            w3 v2 Nn1
+            """,
+            """\
+            n2 v1 x1 y1
+            w3 v1 Nn2
+            """]
+
+    for opl in opls:
+        adder(mir, opl, tmp_path)
+
+    h = ListHandler()
+    mir.apply(h, simplify=False)
+
+    assert h.data == ['N1/1', 'N2/1', 'W3/1', 'W3/2']
+
+
+@pytest.mark.parametrize('adder', [add_as_buffer, add_as_file])
+def test_multibuffer_simplify(adder, tmp_path):
+    mir = osmium.MergeInputReader()
+
+    opls = ["""\
+            n1 v1 x1 y1
+            w3 v2 Nn1
+            """,
+            """\
+            n2 v1 x1 y1
+            w3 v1 Nn2
+            """]
+
+    for opl in opls:
+        adder(mir, opl, tmp_path)
+
+    h = ListHandler()
+    mir.apply(h, simplify=True)
+
+    assert h.data == ['N1/1', 'N2/1', 'W3/2']