Skip to content

Preserve headers when copying an empty table #367

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
OskarEichler wants to merge 2 commits into
base: main
Choose a base branch
from
+10 −3
Open

Preserve headers when copying an empty table #367

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
8754ee6
Preserve headers when copying empty CSV tables into another access mode
OskarEichler Aug 27, 2026
71ce191
Add regression coverage for header-only table copies
OskarEichler Aug 28, 2026
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
6 changes: 3 additions & 3 deletions lib/csv/table.rb
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -240,7 +240,7 @@ def initialize(array_of_rows, headers: nil)
#
# Also note that changes to the duplicate table will not affect the original.
def by_col
self.class.new(@table.dup).by_col!
self.class.new(@table.dup, headers: headers).by_col!
end

# :call-seq:
Expand Down Expand Up @@ -278,7 +278,7 @@ def by_col!
#
# Also note that changes to the duplicate table will not affect the original.
def by_col_or_row
self.class.new(@table.dup).by_col_or_row!
self.class.new(@table.dup, headers: headers).by_col_or_row!
end

# :call-seq:
Expand Down Expand Up @@ -316,7 +316,7 @@ def by_col_or_row!
#
# Also note that changes to the duplicate table will not affect the original.
def by_row
self.class.new(@table.dup).by_row!
self.class.new(@table.dup, headers: headers).by_row!
end

# :call-seq:
Expand Down
7 changes: 7 additions & 0 deletions test/csv/test_table.rb
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -51,6 +51,13 @@ def test_modes
assert_equal(:col_or_row, @table.mode)
end

def test_copy_modes_preserve_header_only_table_headers
[:by_col, :by_row, :by_col_or_row].each do |mode|
copied = @header_only_table.public_send(mode)
assert_equal(%w[A B C], copied.headers, mode)
end
end

def test_headers
assert_equal(@rows.first.headers, @table.headers)
end
Expand Down