@stackline/update-section

Compatibility-first replacement of generated text sections. The package keeps the callable [email protected] API, has no runtime dependencies, supports CommonJS and ESM, and includes first-party TypeScript declarations.

const updateSection = require('@stackline/update-section')

const result = updateSection(
  'title\n<!-- START -->\nold\n<!-- END -->',
  '<!-- START -->\ncurrent\n<!-- END -->',
  (line) => line === '<!-- START -->',
  (line) => line === '<!-- END -->'
)

The default export has this signature:

updateSection(content, section, matchesStart, matchesEnd, top?): string

It replaces the first start marker through the first following end marker. A start without an end is replaced through EOF. If no start exists, the section is appended with exactly two LF characters; pass true as top to prepend it with the same separator.

updateSection.parse(lines, matchesStart, matchesEnd) returns hasStart, hasEnd, startIdx, and endIdx. Indexes are inclusive. A missing end has hasEnd: false and uses the final line as endIdx; end markers before the selected start are ignored.

ESM provides default updateSection plus named updateSection and parse exports. The historical update-section.js deep entry remains available.

Legacy consumers can migrate without changing their import key:

npm install update-section@npm:@stackline/update-section

Supported Node.js versions are 12 through 24. Input continues to split and join on LF exactly, so CR characters in CRLF content remain visible to marker callbacks. The package is an independent continuation and is not affiliated with the original author.