Validation rules that catch real problems
Start with heading hierarchy: H1 should appear once, levels should not skip, and no heading should be empty. Then check table integrity — every row in a pipe table should have the same column count. List items should not contain stray paragraphs that break the grouping. These three rules catch the majority of conversion defects that cause downstream failures.
Structure preservation checks
Beyond syntax validation, check that the Markdown preserves the semantic structure of the source. A PDF with five H2 sections should produce Markdown with five H2 sections. A DOCX with a three-column table should produce a three-column pipe table. Comparing source structure to output structure catches silent losses where the converter produced valid Markdown but dropped content.
Error handling for batch pipelines
When a batch of 100 documents produces 3 failures, the pipeline should not block on those failures. Log the failures with enough context to reproduce (source file path, error type, page number if applicable), continue processing the remaining files, and produce a summary report. Operators can then re-process just the failed files after fixing the source or adjusting conversion settings. Feedback: sapsap@qq.com.