fix(parser): do not append a table row when a blank line closed the table

[leandrocp]

The bug

MDEx.FragmentParser.complete/2 appended a phantom | - | row to a table that had already been closed by a trailing blank line.

maybe_complete_table/2 only checked that the trailing whitespace starts with \n. It never looked at the rest, so "...| 1 |\n\n" was treated the same as "...| 1 |\n" — an open table still being streamed.

Reproducer on main:

MDEx.FragmentParser.complete("| a |\n|---|\n| 1 |\n\n")
#=> "| a |\n|---|\n| 1 |\n| - |\n"    # phantom row

MDEx.FragmentParser.complete("| a | b |\n|---|---|\n| 1 | 2 |\n\n")
#=> "| a | b |\n|---|---|\n| 1 | 2 |\n| - | - |\n"

MDEx.FragmentParser.complete("# h\n\n| a |\n|---|\n| 1 |\n\n")
#=> "# h\n\n| a |\n|---|\n| 1 |\n| - |\n"

During streaming this meant every table rendered with an extra empty row until the end of input.

The change

maybe_complete_table/2 now bails out when the trailing whitespace contains a second newline, i.e. a blank line closed the block.

A table whose source ends immediately after a row (no blank line) is still considered open and keeps the existing behaviour of getting a separator/row appended.

Tests

Four regression tests in test/mdex/fragment_parser_test.exs covering the closed-by-blank-line cases (single column, multi column, after another block) plus an assertion that the still-open case is unchanged. Suite goes from 825 to 829 passing; no existing test asserted the old output.

Summary by CodeRabbit

• Bug Fixes

  • Improved Markdown table completion to avoid adding separator rows when a blank line follows the table.
  • Continued completing open tables that are not followed by a blank line.
  • Improved handling of single-column, multi-column, and tables following other content.

• Tests

  • Added coverage for table completion behavior around blank-line boundaries.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Path: .coderabbit.yaml

Review profile: CHILL

Plan: Team

Run ID: ec90a8c5-f8e4-45e8-ab4c-66c834b78a1e

📥 Commits

Reviewing files that changed from the base of the PR and between 20e850a and 3442865.

📒 Files selected for processing (2)

• lib/mdex/fragment_parser.ex
• test/mdex/fragment_parser_test.exs

Included review availability: Your plan provides up to 2 included reviews per hour; 1 remains after this review.

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📝 Walkthrough

Walkthrough

The fragment parser now avoids adding a table separator when a blank line follows the table header. Tests cover blank-line-terminated tables and open tables.

Changes

Table Completion

Layer / File(s)	Summary
Conditional table completion lib/mdex/fragment_parser.ex, test/mdex/fragment_parser_test.exs	maybe_complete_table checks for a following blank line before adding a separator. Tests cover single-column, multi-column, post-heading, and open-table cases.

Estimated code review effort: 2 (Simple) | ~10 minutes

Merge Risk: ⚪ Minimal · up to 34428

This change prevents fragment completion from appending a phantom table row after a blank line while retaining completion for open tables. Covered boundary and unchanged behaviors leave no current merge-blocking risk.

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check. Docstring coverage is scoped to functions touched by this diff. Analyzed 0 functions across 2…
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title clearly and concisely describes the main parser fix: it prevents a phantom table row after a blank line closes the table.

✨ Finishing Touches

📝 Generate docstrings

• Create stacked PR
• Commit on current branch

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch fix-table-fragment-completion

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