Back to Repositories

Testing Git Patch Deletion Processing in PR-Agent

A comprehensive test suite for validating the omit_deletion_hunks function in the pr-agent repository, which handles patch file processing by removing deletion hunks and preserving added lines. The tests verify the function’s ability to process different patch scenarios and maintain patch file integrity.

Test Coverage Overview

The test suite provides thorough coverage of the omit_deletion_hunks function’s core functionality.

Key areas tested include:

Simple patch additions processing
Multiple hunk concatenation
Deletion-only patch handling
Empty patch processing
Single hunk validation

Edge cases covered include patches with only deletions, empty patches, and mixed content patches.

Implementation Analysis

The testing approach uses pytest’s assertion-based validation to verify patch processing outcomes. Each test case follows a clear pattern of input preparation, function execution, and output validation.

Technical implementation features:

Structured test methods with descriptive names
Consistent input/output pattern testing
Isolated test cases for specific scenarios

Technical Details

Testing tools and configuration:

Testing Framework: pytest
Test File Location: tests/unittest/test_delete_hunks.py
Primary Module Tested: pr_agent.algo.git_patch_processing
Key Function: omit_deletion_hunks

Best Practices Demonstrated

The test suite exemplifies several testing best practices including comprehensive scenario coverage and clear test organization.

Notable practices:

Descriptive test method names
Isolated test cases
Comprehensive edge case coverage
Clear input/output validation
Consistent test structure

codium-ai/pr-agent

tests/unittest/test_delete_hunks.py

            
# Generated by CodiumAI

from pr_agent.algo.git_patch_processing import omit_deletion_hunks

"""
Code Analysis

Objective:
The objective of the "omit_deletion_hunks" function is to remove deletion hunks from a patch file and return only the
added lines.

Inputs:
- "patch_lines": a list of strings representing the lines of a patch file.

Flow:
- Initialize empty lists "temp_hunk" and "added_patched", and boolean variables "add_hunk" and "inside_hunk".
- Compile a regular expression pattern to match hunk headers.
- Iterate through each line in "patch_lines".
- If the line starts with "@@", match the line with the hunk header pattern, finish the previous hunk if necessary,
and append the line to "temp_hunk".
- If the line does not start with "@@", append the line to "temp_hunk", check if it is an added line, and set
"add_hunk" to True if it is.
- If the function reaches the end of "patch_lines" and there is an unfinished hunk with added lines, append it to
"added_patched".
- Join the lines in "added_patched" with newline characters and return the resulting string.

Outputs:
- A string representing the added lines in the patch file.

Additional aspects:
- The function only considers hunks with added lines and ignores hunks with deleted lines.
- The function assumes that the input patch file is well-formed and follows the unified diff format.
"""


class TestOmitDeletionHunks:
    # Tests that the function correctly handles a simple patch containing only additions
    def test_simple_patch_additions(self):
        patch_lines = ['@@ -1,0 +1,1 @@
', '+added line
']
        expected_output = '@@ -1,0 +1,1 @@

+added line
'
        assert omit_deletion_hunks(patch_lines) == expected_output

    # Tests that the function correctly omits deletion hunks and concatenates multiple hunks in a patch.
    def test_patch_multiple_hunks(self):
        patch_lines = ['@@ -1,0 +1,1 @@
', '-deleted line', '+added line
', '@@ -2,0 +3,1 @@
', '-deleted line
',
                       '-another deleted line
']
        expected_output = '@@ -1,0 +1,1 @@

-deleted line
+added line
'
        assert omit_deletion_hunks(patch_lines) == expected_output

    # Tests that the function correctly omits deletion lines from the patch when there are no additions or context
    # lines.
    def test_patch_only_deletions(self):
        patch_lines = ['@@ -1,1 +1,0 @@
', '-deleted line
']
        expected_output = ''
        assert omit_deletion_hunks(patch_lines) == expected_output

        # Additional deletion lines
        patch_lines = ['@@ -1,1 +1,0 @@
', '-deleted line
', '-another deleted line
']
        expected_output = ''
        assert omit_deletion_hunks(patch_lines) == expected_output

        # Additional context lines
        patch_lines = ['@@ -1,1 +1,0 @@
', '-deleted line
', '-another deleted line
', 'context line 1
',
                       'context line 2
', 'context line 3
']
        expected_output = ''
        assert omit_deletion_hunks(patch_lines) == expected_output

    # Tests that the function correctly handles an empty patch
    def test_empty_patch(self):
        patch_lines = []
        expected_output = ''
        assert omit_deletion_hunks(patch_lines) == expected_output

    # Tests that the function correctly handles a patch containing only one hunk
    def test_patch_one_hunk(self):
        patch_lines = ['@@ -1,0 +1,1 @@
', '+added line
']
        expected_output = '@@ -1,0 +1,1 @@

+added line
'
        assert omit_deletion_hunks(patch_lines) == expected_output

    # Tests that the function correctly handles a patch containing only deletions and no additions
    def test_patch_deletions_no_additions(self):
        patch_lines = ['@@ -1,1 +1,0 @@
', '-deleted line
']
        expected_output = ''
        assert omit_deletion_hunks(patch_lines) == expected_output