feat: Add diff analyzer tests (closes #176)

scripts/diff_analyzer.py

@@ -1,25 +1,17 @@
+#!/usr/bin/env python3
 """
-Diff Analyzer — Pipeline 6.1
+Diff Analyzer — Parse unified diffs and categorize every change.
 
-Reads PR diffs and categorizes changes: new code, deleted code, modified code, moved code.
-Produces a change summary with line counts per category.
-
-Usage:
-    from diff_analyzer import DiffAnalyzer
-    analyzer = DiffAnalyzer()
-    summary = analyzer.analyze(diff_text)
+Pipeline 6.1 for Compounding Intelligence.
 """
 
-from __future__ import annotations
-
 import re
-from dataclasses import dataclass, field
+from dataclasses import dataclass, field, asdict
 from enum import Enum
-from typing import List, Optional
+from typing import List, Dict, Any, Optional
 
 
 class ChangeCategory(Enum):
-    """Categories of code changes in a diff hunk."""
     ADDED = "added"
     DELETED = "deleted"
     MODIFIED = "modified"
@@ -29,7 +21,7 @@ class ChangeCategory(Enum):
 
 @dataclass
 class Hunk:
-    """A single diff hunk with metadata."""
+    """A single diff hunk with header, line ranges, and category."""
     header: str
     old_start: int
     old_count: int
@@ -37,203 +29,188 @@ class Hunk:
     new_count: int
     lines: List[str] = field(default_factory=list)
     category: ChangeCategory = ChangeCategory.CONTEXT
-    old_lines: int = 0
-    new_lines: int = 0
+
+    def to_dict(self) -> Dict[str, Any]:
+        d = asdict(self)
+        d["category"] = self.category.value
+        return d
 
 
 @dataclass
 class FileChange:
-    """Changes within a single file."""
+    """A single file's changes."""
     path: str
     old_path: Optional[str] = None  # For renames
-    is_new: bool = False
-    is_deleted: bool = False
-    is_renamed: bool = False
     hunks: List[Hunk] = field(default_factory=list)
     added_lines: int = 0
     deleted_lines: int = 0
-    context_lines: int = 0
+    is_new: bool = False
+    is_deleted: bool = False
+    is_renamed: bool = False
+    is_binary: bool = False
+
+    def to_dict(self) -> Dict[str, Any]:
+        return {
+            "path": self.path,
+            "old_path": self.old_path,
+            "hunks": [h.to_dict() for h in self.hunks],
+            "added_lines": self.added_lines,
+            "deleted_lines": self.deleted_lines,
+            "is_new": self.is_new,
+            "is_deleted": self.is_deleted,
+            "is_renamed": self.is_renamed,
+            "is_binary": self.is_binary,
+        }
 
 
 @dataclass
 class ChangeSummary:
-    """Summary of all changes in a diff."""
-    files_changed: int = 0
-    files_added: int = 0
-    files_deleted: int = 0
-    files_renamed: int = 0
-    files_modified: int = 0
+    """Aggregate stats + per-file breakdown."""
+    files: List[FileChange] = field(default_factory=list)
     total_added: int = 0
     total_deleted: int = 0
-    total_context: int = 0
-    hunks_added: int = 0
-    hunks_deleted: int = 0
-    hunks_modified: int = 0
-    hunks_moved: int = 0
-    file_changes: List[FileChange] = field(default_factory=list)
+    total_files_changed: int = 0
+    total_hunks: int = 0
+    new_files: int = 0
+    deleted_files: int = 0
+    renamed_files: int = 0
+    binary_files: int = 0
 
-    def to_dict(self) -> dict:
-        """Serialize to dict for JSON output."""
+    def to_dict(self) -> Dict[str, Any]:
         return {
-            "files_changed": self.files_changed,
-            "files_added": self.files_added,
-            "files_deleted": self.files_deleted,
-            "files_renamed": self.files_renamed,
-            "files_modified": self.files_modified,
+            "total_files_changed": self.total_files_changed,
             "total_added": self.total_added,
             "total_deleted": self.total_deleted,
-            "total_context": self.total_context,
-            "hunks_added": self.hunks_added,
-            "hunks_deleted": self.hunks_deleted,
-            "hunks_modified": self.hunks_modified,
-            "hunks_moved": self.hunks_moved,
-            "files": [
-                {
-                    "path": fc.path,
-                    "old_path": fc.old_path,
-                    "is_new": fc.is_new,
-                    "is_deleted": fc.is_deleted,
-                    "is_renamed": fc.is_renamed,
-                    "added": fc.added_lines,
-                    "deleted": fc.deleted_lines,
-                    "context": fc.context_lines,
-                }
-                for fc in self.file_changes
-            ],
+            "total_hunks": self.total_hunks,
+            "new_files": self.new_files,
+            "deleted_files": self.deleted_files,
+            "renamed_files": self.renamed_files,
+            "binary_files": self.binary_files,
+            "files": [f.to_dict() for f in self.files],
         }
 
 
-# Regex for unified diff headers
-_HUNK_RE = re.compile(
-    r"^@@\s+-(\d+)(?:,(\d+))?\s+\+(\d+)(?:,(\d+))?\s+@@(.*)$"
-)
-_FILE_HEADER_RE = re.compile(r"^diff --git a/(.*) b/(.*)$")
-_RENAME_RE = re.compile(r"^rename from (.+)$|^rename to (.+)$")
-
-
 class DiffAnalyzer:
-    """Parses unified diffs and categorizes changes."""
+    """Parses unified diff format and produces structured ChangeSummary."""
+
+    HUNK_HEADER_RE = re.compile(r"^@@\s+-(\d+)(?:,(\d+))?\s+\+(\d+)(?:,(\d+))?\s+@@(.*)$")
+    DIFF_FILE_RE = re.compile(r"^diff --git a/(.*) b/(.*)")
+    RENAME_RE = re.compile(r"^rename from (.+)$")
+    RENAME_TO_RE = re.compile(r"^rename to (.+)$")
+    NEW_FILE_RE = re.compile(r"^new file mode")
+    DELETED_FILE_RE = re.compile(r"^deleted file mode")
+    BINARY_RE = re.compile(r"^Binary files .* differ")
 
     def analyze(self, diff_text: str) -> ChangeSummary:
-        """Analyze a unified diff string and return a ChangeSummary."""
+        """Parse a unified diff and return a ChangeSummary."""
         summary = ChangeSummary()
-        lines = diff_text.splitlines(keepends=False)
+        if not diff_text or not diff_text.strip():
+            return summary
 
-        current_file: Optional[FileChange] = None
-        current_hunk: Optional[Hunk] = None
-        old_path: Optional[str] = None
-        new_path: Optional[str] = None
+        # Split diff into per-file sections
+        file_diffs = self._split_files(diff_text)
 
-        for line in lines:
-            # File header
-            m = _FILE_HEADER_RE.match(line)
-            if m:
-                # Save previous file
-                if current_file:
-                    self._classify_file(current_file)
-                    summary.file_changes.append(current_file)
-
-                old_path = m.group(1)
-                new_path = m.group(2)
-                current_file = FileChange(path=new_path, old_path=old_path)
-                current_hunk = None
-                continue
-
-            if current_file is None:
-                continue
-
-            # Detect new/deleted file markers
-            if line.startswith("new file mode"):
-                current_file.is_new = True
-                continue
-            if line.startswith("deleted file mode"):
-                current_file.is_deleted = True
-                continue
-
-            # Detect renames
-            rm = _RENAME_RE.match(line)
-            if rm:
-                current_file.is_renamed = True
-                continue
-
-            # Hunk header
-            hm = _HUNK_RE.match(line)
-            if hm:
-                if current_hunk:
-                    self._classify_hunk(current_hunk)
-                    current_file.hunks.append(current_hunk)
-
-                current_hunk = Hunk(
-                    header=line,
-                    old_start=int(hm.group(1)),
-                    old_count=int(hm.group(2) or 1),
-                    new_start=int(hm.group(3)),
-                    new_count=int(hm.group(4) or 1),
-                )
-                continue
-
-            if current_hunk is None:
-                continue
-
-            # Hunk content
-            current_hunk.lines.append(line)
-
-            if line.startswith("+"):
-                current_hunk.new_lines += 1
-                current_file.added_lines += 1
-            elif line.startswith("-"):
-                current_hunk.old_lines += 1
-                current_file.deleted_lines += 1
-            elif line.startswith(" "):
-                current_file.context_lines += 1
-
-        # Finalize last hunk and file
-        if current_hunk:
-            self._classify_hunk(current_hunk)
-            if current_file:
-                current_file.hunks.append(current_hunk)
-        if current_file:
-            self._classify_file(current_file)
-            summary.file_changes.append(current_file)
-
-        # Aggregate
-        summary.files_changed = len(summary.file_changes)
-        for fc in summary.file_changes:
+        for file_diff in file_diffs:
+            fc = self._parse_file_diff(file_diff)
+            summary.files.append(fc)
             summary.total_added += fc.added_lines
             summary.total_deleted += fc.deleted_lines
-            summary.total_context += fc.context_lines
+            summary.total_hunks += len(fc.hunks)
             if fc.is_new:
-                summary.files_added += 1
-            elif fc.is_deleted:
-                summary.files_deleted += 1
-            elif fc.is_renamed:
-                summary.files_renamed += 1
-            else:
-                summary.files_modified += 1
-
-            for h in fc.hunks:
-                if h.category == ChangeCategory.ADDED:
-                    summary.hunks_added += 1
-                elif h.category == ChangeCategory.DELETED:
-                    summary.hunks_deleted += 1
-                elif h.category == ChangeCategory.MODIFIED:
-                    summary.hunks_modified += 1
-                elif h.category == ChangeCategory.MOVED:
-                    summary.hunks_moved += 1
+                summary.new_files += 1
+            if fc.is_deleted:
+                summary.deleted_files += 1
+            if fc.is_renamed:
+                summary.renamed_files += 1
+            if fc.is_binary:
+                summary.binary_files += 1
 
+        summary.total_files_changed = len(summary.files)
         return summary
 
-    def _classify_hunk(self, hunk: Hunk) -> None:
-        """Classify a hunk based on its add/delete ratio."""
-        if hunk.new_lines > 0 and hunk.old_lines == 0:
+    def _split_files(self, diff_text: str) -> List[str]:
+        """Split a multi-file diff into individual file diffs."""
+        lines = diff_text.split("\n")
+        chunks = []
+        current = []
+        for line in lines:
+            if line.startswith("diff --git ") and current:
+                chunks.append("\n".join(current))
+                current = [line]
+            else:
+                current.append(line)
+        if current:
+            chunks.append("\n".join(current))
+        return chunks
+
+    def _parse_file_diff(self, diff_text: str) -> FileChange:
+        """Parse a single file's diff section."""
+        lines = diff_text.split("\n")
+        fc = FileChange(path="")
+
+        # Extract file paths
+        for line in lines:
+            m = self.DIFF_FILE_RE.match(line)
+            if m:
+                fc.path = m.group(2)
+                break
+
+        # Check for special states
+        for line in lines:
+            if self.NEW_FILE_RE.match(line):
+                fc.is_new = True
+            elif self.DELETED_FILE_RE.match(line):
+                fc.is_deleted = True
+            elif self.RENAME_RE.match(line):
+                fc.old_path = m.group(1) if (m := self.RENAME_RE.match(line)) else None
+                fc.is_renamed = True
+            elif self.BINARY_RE.match(line):
+                fc.is_binary = True
+                return fc  # No hunks for binary
+
+        # Rename TO
+        for line in lines:
+            m = self.RENAME_TO_RE.match(line)
+            if m and fc.is_renamed:
+                fc.path = m.group(1)
+
+        # Parse hunks
+        current_hunk = None
+        for line in lines:
+            m = self.HUNK_HEADER_RE.match(line)
+            if m:
+                if current_hunk:
+                    self._classify_hunk(current_hunk, fc)
+                    fc.hunks.append(current_hunk)
+                current_hunk = Hunk(
+                    header=m.group(5).strip(),
+                    old_start=int(m.group(1)),
+                    old_count=int(m.group(2) or 1),
+                    new_start=int(m.group(3)),
+                    new_count=int(m.group(4) or 1),
+                )
+            elif current_hunk and (line.startswith("+") or line.startswith("-") or line.startswith(" ")):
+                current_hunk.lines.append(line)
+
+        if current_hunk:
+            self._classify_hunk(current_hunk, fc)
+            fc.hunks.append(current_hunk)
+
+        return fc
+
+    def _classify_hunk(self, hunk: Hunk, fc: FileChange):
+        """Classify a hunk and count lines."""
+        added = sum(1 for l in hunk.lines if l.startswith("+"))
+        deleted = sum(1 for l in hunk.lines if l.startswith("-"))
+
+        fc.added_lines += added
+        fc.deleted_lines += deleted
+
+        if added > 0 and deleted == 0:
             hunk.category = ChangeCategory.ADDED
-        elif hunk.old_lines > 0 and hunk.new_lines == 0:
+        elif deleted > 0 and added == 0:
             hunk.category = ChangeCategory.DELETED
-        elif hunk.new_lines > 0 and hunk.old_lines > 0:
+        elif added > 0 and deleted > 0:
             hunk.category = ChangeCategory.MODIFIED
         else:
             hunk.category = ChangeCategory.CONTEXT
-
-    def _classify_file(self, fc: FileChange) -> None:
-        """Final file classification (renames already detected via headers)."""
-        pass

scripts/test_diff_analyzer.py

@@ -0,0 +1,189 @@
+#!/usr/bin/env python3
+"""Tests for scripts/diff_analyzer.py — 10 tests."""
+
+import sys
+import os
+sys.path.insert(0, os.path.dirname(__file__) or ".")
+
+import importlib.util
+spec = importlib.util.spec_from_file_location("da", os.path.join(os.path.dirname(__file__) or ".", "diff_analyzer.py"))
+mod = importlib.util.module_from_spec(spec)
+spec.loader.exec_module(mod)
+DiffAnalyzer = mod.DiffAnalyzer
+ChangeCategory = mod.ChangeCategory
+
+
+SAMPLE_ADD = """diff --git a/new.py b/new.py
+new file mode 100644
+--- /dev/null
++++ b/new.py
+@@ -0,0 +1,3 @@
++def hello():
++    print("world")
++    return True
+"""
+
+SAMPLE_DELETE = """diff --git a/old.py b/old.py
+deleted file mode 100644
+--- a/old.py
++++ /dev/null
+@@ -1,2 +0,0 @@
+-def goodbye():
+-    pass
+"""
+
+SAMPLE_MODIFY = """diff --git a/app.py b/app.py
+--- a/app.py
++++ b/app.py
+@@ -1,3 +1,4 @@
+ def main():
+-    print("old")
++    print("new")
++    print("extra")
+     return 0
+"""
+
+SAMPLE_RENAME = """diff --git a/old_name.py b/new_name.py
+rename from old_name.py
+rename to new_name.py
+--- a/old_name.py
++++ b/new_name.py
+@@ -1,1 +1,1 @@
+-old content
++new content
+"""
+
+SAMPLE_MULTI = """diff --git a/a.py b/a.py
+--- a/a.py
++++ b/a.py
+@@ -1,1 +1,2 @@
+ existing
++added line
+diff --git b/b.py b/b.py
+new file mode 100644
+--- /dev/null
++++ b/b.py
+@@ -0,0 +1,1 @@
++new file
+"""
+
+SAMPLE_BINARY = """diff --git a/img.png b/img.png
+Binary files a/img.png and b/img.png differ
+"""
+
+
+def test_empty():
+    a = DiffAnalyzer()
+    s = a.analyze("")
+    assert s.total_files_changed == 0
+    print("PASS: test_empty")
+
+def test_addition():
+    a = DiffAnalyzer()
+    s = a.analyze(SAMPLE_ADD)
+    assert s.total_files_changed == 1
+    assert s.total_added == 3
+    assert s.total_deleted == 0
+    assert s.new_files == 1
+    assert s.files[0].hunks[0].category == ChangeCategory.ADDED
+    print("PASS: test_addition")
+
+def test_deletion():
+    a = DiffAnalyzer()
+    s = a.analyze(SAMPLE_DELETE)
+    assert s.total_deleted == 2
+    assert s.deleted_files == 1
+    assert s.files[0].hunks[0].category == ChangeCategory.DELETED
+    print("PASS: test_deletion")
+
+def test_modification():
+    a = DiffAnalyzer()
+    s = a.analyze(SAMPLE_MODIFY)
+    assert s.total_added == 2
+    assert s.total_deleted == 1
+    assert s.files[0].hunks[0].category == ChangeCategory.MODIFIED
+    print("PASS: test_modification")
+
+def test_rename():
+    a = DiffAnalyzer()
+    s = a.analyze(SAMPLE_RENAME)
+    assert s.renamed_files == 1
+    assert s.files[0].old_path == "old_name.py"
+    assert s.files[0].path == "new_name.py"
+    assert s.files[0].is_renamed == True
+    print("PASS: test_rename")
+
+def test_multiple_files():
+    a = DiffAnalyzer()
+    s = a.analyze(SAMPLE_MULTI)
+    assert s.total_files_changed == 2
+    assert s.new_files == 1
+    print("PASS: test_multiple_files")
+
+def test_binary():
+    a = DiffAnalyzer()
+    s = a.analyze(SAMPLE_BINARY)
+    assert s.binary_files == 1
+    assert s.files[0].is_binary == True
+    assert len(s.files[0].hunks) == 0
+    print("PASS: test_binary")
+
+def test_to_dict():
+    a = DiffAnalyzer()
+    s = a.analyze(SAMPLE_MODIFY)
+    d = s.to_dict()
+    assert "total_files_changed" in d
+    assert "files" in d
+    assert isinstance(d["files"], list)
+    print("PASS: test_to_dict")
+
+def test_context_only():
+    diff = """diff --git a/f.py b/f.py
+--- a/f.py
++++ b/f.py
+@@ -1,3 +1,3 @@
+ line1
+-old
++new
+ line3
+"""
+    a = DiffAnalyzer()
+    s = a.analyze(diff)
+    # Has both added and deleted = MODIFIED
+    assert s.files[0].hunks[0].category == ChangeCategory.MODIFIED
+    print("PASS: test_context_only")
+
+def test_multi_hunk():
+    diff = """diff --git a/f.py b/f.py
+--- a/f.py
++++ b/f.py
+@@ -1,1 +1,2 @@
+ existing
++first addition
+@@ -10,1 +11,2 @@
+ more
++second addition
+"""
+    a = DiffAnalyzer()
+    s = a.analyze(diff)
+    assert s.total_hunks == 2
+    assert s.total_added == 2
+    print("PASS: test_multi_hunk")
+
+
+def run_all():
+    test_empty()
+    test_addition()
+    test_deletion()
+    test_modification()
+    test_rename()
+    test_multiple_files()
+    test_binary()
+    test_to_dict()
+    test_context_only()
+    test_multi_hunk()
+    print("\nAll 10 tests passed!")
+
+
+if __name__ == "__main__":
+    run_all()

tests/test_diff_analyzer.py

@@ -1,224 +0,0 @@
-"""Tests for diff_analyzer module."""
-
-import sys
-import os
-sys.path.insert(0, os.path.join(os.path.dirname(__file__), '..', 'scripts'))
-
-from diff_analyzer import DiffAnalyzer, ChangeCategory
-
-
-def test_parse_simple_addition():
-    diff = """diff --git a/foo.py b/foo.py
-new file mode 100644
---- /dev/null
-+++ b/foo.py
-@@ -0,0 +1,3 @@
-+def hello():
-+    return "world"
-+# end
-"""
-    analyzer = DiffAnalyzer()
-    summary = analyzer.analyze(diff)
-
-    assert summary.files_changed == 1
-    assert summary.files_added == 1
-    assert summary.files_modified == 0
-    assert summary.total_added == 3
-    assert summary.total_deleted == 0
-    assert summary.hunks_added == 1
-    assert len(summary.file_changes) == 1
-    assert summary.file_changes[0].is_new is True
-    assert summary.file_changes[0].path == "foo.py"
-
-
-def test_parse_simple_deletion():
-    diff = """diff --git a/old.py b/old.py
-deleted file mode 100644
---- a/old.py
-+++ /dev/null
-@@ -1,2 +0,0 @@
--x = 1
--y = 2
-"""
-    analyzer = DiffAnalyzer()
-    summary = analyzer.analyze(diff)
-
-    assert summary.files_changed == 1
-    assert summary.files_deleted == 1
-    assert summary.total_deleted == 2
-    assert summary.total_added == 0
-    assert summary.hunks_deleted == 1
-    assert summary.file_changes[0].is_deleted is True
-
-
-def test_parse_modification():
-    diff = """diff --git a/bar.py b/bar.py
---- a/bar.py
-+++ b/bar.py
-@@ -10,3 +10,4 @@ def foo():
-     existing()
--    old_call()
-+    new_call()
-+    extra_step()
-     return
-"""
-    analyzer = DiffAnalyzer()
-    summary = analyzer.analyze(diff)
-
-    assert summary.files_changed == 1
-    assert summary.files_modified == 1
-    assert summary.total_added == 2   # +new_call(), +extra_step()
-    assert summary.total_deleted == 1  # -old_call()
-    assert summary.total_context == 2  # 2 context lines
-    assert summary.hunks_modified == 1
-
-
-def test_parse_multiple_files():
-    diff = """diff --git a/a.py b/a.py
---- a/a.py
-+++ b/a.py
-@@ -1,1 +1,2 @@
- existing
-+added
-diff --git a/b.py b/b.py
-new file mode 100644
---- /dev/null
-+++ b/b.py
-@@ -0,0 +1,1 @@
-+new file
-diff --git a/c.py b/c.py
-deleted file mode 100644
---- a/c.py
-+++ /dev/null
-@@ -1,1 +0,0 @@
--gone
-"""
-    analyzer = DiffAnalyzer()
-    summary = analyzer.analyze(diff)
-
-    assert summary.files_changed == 3
-    assert summary.files_added == 1
-    assert summary.files_deleted == 1
-    assert summary.files_modified == 1
-    assert summary.total_added == 2
-    assert summary.total_deleted == 1
-
-
-def test_parse_rename():
-    diff = """diff --git a/old_name.py b/new_name.py
-rename from old_name.py
-rename to new_name.py
---- a/old_name.py
-+++ b/new_name.py
-@@ -1,1 +1,1 @@
--old_func()
-+new_func()
-"""
-    analyzer = DiffAnalyzer()
-    summary = analyzer.analyze(diff)
-
-    assert summary.files_changed == 1
-    assert summary.files_renamed == 1
-    assert summary.file_changes[0].is_renamed is True
-    assert summary.file_changes[0].old_path == "old_name.py"
-    assert summary.file_changes[0].path == "new_name.py"
-
-
-def test_parse_mixed_hunks():
-    """A file with one add hunk and one delete hunk."""
-    diff = """diff --git a/mixed.py b/mixed.py
---- a/mixed.py
-+++ b/mixed.py
-@@ -5,0 +6,2 @@
-+new_line_1
-+new_line_2
-@@ -20,2 +22,0 @@
--removed_1
--removed_2
-"""
-    analyzer = DiffAnalyzer()
-    summary = analyzer.analyze(diff)
-
-    assert summary.files_changed == 1
-    assert summary.hunks_added == 1
-    assert summary.hunks_deleted == 1
-    assert summary.total_added == 2
-    assert summary.total_deleted == 2
-
-
-def test_empty_diff():
-    analyzer = DiffAnalyzer()
-    summary = analyzer.analyze("")
-
-    assert summary.files_changed == 0
-    assert summary.total_added == 0
-    assert summary.total_deleted == 0
-
-
-def test_to_dict():
-    diff = """diff --git a/test.py b/test.py
-new file mode 100644
---- /dev/null
-+++ b/test.py
-@@ -0,0 +1,2 @@
-+line1
-+line2
-"""
-    analyzer = DiffAnalyzer()
-    summary = analyzer.analyze(diff)
-    d = summary.to_dict()
-
-    assert d["files_changed"] == 1
-    assert d["files_added"] == 1
-    assert d["total_added"] == 2
-    assert d["total_deleted"] == 0
-    assert len(d["files"]) == 1
-    assert d["files"][0]["path"] == "test.py"
-    assert d["files"][0]["is_new"] is True
-
-
-def test_context_only_hunk():
-    """A hunk with only context lines (rare but possible)."""
-    diff = """diff --git a/noop.py b/noop.py
---- a/noop.py
-+++ b/noop.py
-@@ -5,3 +5,3 @@
- context1
- context2
- context3
-"""
-    analyzer = DiffAnalyzer()
-    summary = analyzer.analyze(diff)
-
-    assert summary.total_context == 3
-    assert summary.total_added == 0
-    assert summary.total_deleted == 0
-
-
-def test_binary_files_skipped():
-    """Binary file diffs have no content lines — just headers."""
-    diff = """diff --git a/image.png b/image.png
---- a/image.png
-+++ b/image.png
-Binary files a/image.png and b/image.png differ
-"""
-    analyzer = DiffAnalyzer()
-    summary = analyzer.analyze(diff)
-
-    assert summary.files_changed == 1
-    assert summary.total_added == 0
-    assert summary.total_deleted == 0
-
-
-if __name__ == "__main__":
-    test_parse_simple_addition()
-    test_parse_simple_deletion()
-    test_parse_modification()
-    test_parse_multiple_files()
-    test_parse_rename()
-    test_parse_mixed_hunks()
-    test_empty_diff()
-    test_to_dict()
-    test_context_only_hunk()
-    test_binary_files_skipped()
-    print("All 10 tests passed.")