refactor: remove redundant inclusion of header files in the fuzz tests #23294

This PR removes redundant inclusion of header files in the fuzz test files. Most of the header files like #include<string>, #include<vector> etc.. are redundant because it’s imports are already included in one of these header files - src/test/fuzz/fuzz.h, src/test/fuzz/util.h and src/test/fuzz/FuzzedDataProvider.h. So they can be removed.

This bash script was used to delete redundant import occurrences. The text files headers-fuzz.txt, headers-util.txt and headers-FuzzedDataProvider.txt were provided with the header file information which are present in src/test/fuzz/fuzz.h, src/test/fuzz/util.h and src/test/fuzz/FuzzedDataProvider.h respectively.

#!/bin/bash
remove-lines() (
  remove_lines="$1"
  all_lines="$2"
  tmp_file="$(mktemp)"
  grep -Fvxf "$remove_lines" "$all_lines" > "$tmp_file"
  mv "$tmp_file" "$all_lines"
)

for filename in bitcoin/src/test/fuzz/*.cpp; do
    # if FuzzedDataProvider.h is imported
    if grep -q "#include <test/fuzz/FuzzedDataProvider.h>" "$filename"
    then
        remove-lines "headers-FuzzedDataProvider.txt" "$filename"
    fi
    # if fuzz.h is imported
    if grep -q "#include <test/fuzz/fuzz.h>" "$filename"
    then
        remove-lines "headers-fuzz.txt" "$filename"
    fi
    # if util.h is imported
    if grep -q "#include <test/fuzz/util.h>" "$filename"
    then
        remove-lines "headers-util.txt" "$filename"
    fi
    # don't let 2 empty lines occur after deletion
    tempfile=$(cat -s "$filename")
    echo "$tempfile" > "$filename";
done

@stratospher

The "include-what-you-use" policy is used in Bitcoin Core. See the "Source code organization" section in the developer notes:

• Every .cpp and .h file should #include every header file it directly uses classes, functions or other definitions from, even if those headers are already included indirectly through other headers.

  • Rationale: Excluding headers because they are already indirectly included results in compilation failures when those indirect dependencies change. Furthermore, it obscures what the real code dependencies are.

Thanks for clarifying! Closing this PR.