week9-10

For the past two weeks, I’ve been refining my code based on feedback .One of the additions I’ve made is: *add smudge/clean filters in the test ‘merge with conflict outside cone’. This is because the changes in the attr.c portion from the last patch can affect the behavior of sparse index-integrated commands that read attributes, such as ‘git merge’. To comprehensively verify whether the attributes can be successfully read, we also need to add some tests that concern the commands related to this code to ensure the modified code can now properly read attributes. One approach is to take the ‘t1092’ test ‘merge with conflict outside cone’, include smudge/clean filters in the .gitattributes files located within the affected sparse directories.

The clean/smudge filter is quite simple to use. Create a filter driver with two commands—clean and smudge—and then apply the filter per record in the .gitattributes file.

echo "a filter=rot13" >>.gitattributes &&
run_on_sparse mkdir folder1 &&
run_on_all cp ../.gitattributes ./folder1 &&
git -C full-checkout add folder1/.gitattributes &&
run_on_sparse git add --sparse folder1/.gitattributes &&
run_on_all git commit -m "add .gitattributes" &&
test_sparse_match git sparse-checkout reapply &&
git config filter.rot13.clean "tr 'A-Za-z' 'N-ZA-Mn-za-m'" &&
git config filter.rot13.smudge "tr 'A-Za-z' 'N-ZA-Mn-za-m'" &&

In a nutshell, this code sets up and tests a ROT13 filter in a Git repo and applies it to files named a.

The test passed successfully, but in the feedback, my mentor asked me to demonstrate that the ‘merge with conflict outside cone’ test could not pass before the changes to attr.c, but could successfully pass after. To my surprise, I found that after making modifications to ‘merge with conflict outside cone’, the test passed regardless of whether the attr.c code was altered or not. This indicates that the clean and smudge filters weren’t applied effectively. After multiple unsuccessful attempts to rectify this, I decided to focus on other functions that call ‘git_check_attr()’, such as ‘whitespace_rule()’.

Add a test ‘diff –check with pathspec outside sparse definition’.It starts by disabling the trailing whitespace and space-before-tabchecks using the core. whitespace configuration option. Then, itspecifically re-enables the trailing whitespace check for a file located in a sparse directory. This is accomplished by adding a whitespace=trailing-space rule to the .gitattributes file within that directory. To ensure that only the .gitattributes file in the index is
being read, and not any .gitattributes files in the working tree, the test removes the .gitattributes file from the working tree after adding it to the index. The final part of the test uses ‘git diff –check’ to verify the correct application of the attribute rules. This ensures that the .gitattributes file is correctly read from index and applied, even when the file’s path falls outside of the sparse-checkout definition.

The newly added test effectively showcases the difference in outcomes before and after modifying the read_attr_from_index() function – transitioning from a failed test to a successful one. Following this, I reorganized the order of the patches to provide a clearer narrative of the issue and its resolution. t1092: add tests for git check-attr attr.c: enable reading attributes in a sparse directory check-attr: integrate with sparse-index By restructuring the patches in this manner, we introduce a failing test case in patch 1, which then reverts back to “test_expect_success” by the time we reach patch 2. This strategy is specifically devised to highlight the necessity of reading attributes from a sparse directory. Without this capability, the sparse index doesn’t function correctly in the context of git check-attr.”

patch V4 Link