Add test configuration and parser/language detector tests

tests/test_diff_parser.py

@@ -0,0 +1,150 @@
+"""Tests for the DiffParser module."""
+
+import sys
+from pathlib import Path
+
+sys.path.insert(0, str(Path(__file__).parent.parent / 'src'))
+
+from gdiffer.parser import DiffParser, parse_diff
+from gdiffer.models import DiffFile, DiffHunk
+
+
+class TestDiffParser:
+    def test_parse_simple_diff(self, diff_parser, sample_diff):
+        files = diff_parser.parse(sample_diff)
+        assert len(files) == 1
+        assert files[0].filename == "src/main.py"
+        assert len(files[0].hunks) == 1
+
+    def test_parse_new_file(self, diff_parser):
+        diff = """diff --git a/new_file.py b/new_file.py
+new file mode 100644
+index 0000000..1234567
+--- /dev/null
++++ b/new_file.py
+@@ -0,0 +1,3 @@
++def new_function():
++    pass
+"""
+        files = diff_parser.parse(diff)
+        assert len(files) == 1
+        assert files[0].is_new
+        assert files[0].change_type == "add"
+
+    def test_parse_deleted_file(self, diff_parser):
+        diff = """diff --git a/old_file.py b/old_file.py
+deleted file mode 100644
+index 1234567..0000000
+--- a/old_file.py
++++ /dev/null
+@@ -1,3 +0,0 @@
+-def old_function():
+-    pass
+-
+"""
+        files = diff_parser.parse(diff)
+        assert len(files) == 1
+        assert files[0].is_deleted
+        assert files[0].change_type == "delete"
+
+    def test_parse_rename(self, diff_parser):
+        diff = """diff --git a/old_name.py b/new_name.py
+similarity index 95%
+rename from old_name.py
+rename to new_name.py
+index 1234567..89abcde 100644
+--- a/old_name.py
++++ b/new_name.py
+@@ -1,3 +1,3 @@
+ def renamed_function():
+-    return "old"
++    return "new""""
+        files = diff_parser.parse(diff)
+        assert len(files) == 1
+        assert files[0].is_rename
+        assert files[0].rename_from == "old_name.py"
+        assert files[0].change_type == "rename"
+
+    def test_parse_multi_file(self, diff_parser, multi_file_diff):
+        files = diff_parser.parse(multi_file_diff)
+        assert len(files) == 3
+        file_types = [f.change_type for f in files]
+        assert "add" in file_types
+        assert "delete" in file_types
+        assert "modify" in file_types
+
+    def test_get_added_lines(self, diff_parser):
+        diff = """diff --git a/test.py b/test.py
+--- a/test.py
++++ b/test.py
+@@ -1,3 +1,5 @@
++import os
++import sys
+ def test():
+     return True
+"""
+        files = diff_parser.parse(diff)
+        hunk = files[0].hunks[0]
+        added_lines = hunk.get_added_lines()
+        assert len(added_lines) == 2
+
+    def test_get_removed_lines(self, diff_parser):
+        diff = """diff --git a/test.py b/test.py
+--- a/test.py
++++ b/test.py
+@@ -1,3 +1,2 @@
+-import os
+ def test():
+     return True
+"""
+        files = diff_parser.parse(diff)
+        hunk = files[0].hunks[0]
+        removed_lines = hunk.get_removed_lines()
+        assert len(removed_lines) == 1
+
+    def test_empty_diff(self, diff_parser):
+        files = diff_parser.parse("")
+        assert len(files) == 0
+
+    def test_parse_diff_function(self):
+        diff = """diff --git a/test.py b/test.py
+--- a/test.py
++++ b/test.py
+@@ -1 +1 @@
+-old
++new
+"""
+        files = parse_diff(diff)
+        assert len(files) == 1
+        assert files[0].filename == "test.py"
+
+
+class TestDiffFile:
+    def test_filename_property(self):
+        file_obj = DiffFile(old_path="old.py", new_path="new.py")
+        assert file_obj.filename == "new.py"
+
+    def test_filename_only_old_path(self):
+        file_obj = DiffFile(old_path="old.py", new_path=None)
+        assert file_obj.filename == "old.py"
+
+    def test_is_new_property(self):
+        file_obj = DiffFile(old_path=None, new_path="new.py", new_file_mode="100644")
+        assert file_obj.is_new
+
+    def test_is_deleted_property(self):
+        file_obj = DiffFile(old_path="old.py", new_path=None, deleted_file_mode="100644")
+        assert file_obj.is_deleted
+
+    def test_is_rename_property(self):
+        file_obj = DiffFile(old_path="old.py", new_path="new.py", rename_from="old.py", rename_to="new.py")
+        assert file_obj.is_rename
+
+
+class TestDiffHunk:
+    def test_get_modified_lines(self):
+        hunk = DiffHunk(old_start=1, old_lines=3, new_start=1, new_lines=3,
+                        old_lines_content=["-old1", "-old2", "-old3"],
+                        new_lines_content=["+new1", "+new2", "+new3"])
+        modified = hunk.get_modified_lines()
+        assert len(modified) == 3