Collapsed-field multi-run replay broken in Deleted/MovedSource inplace paths

[stevenobiajulu]

Summary

The inplace modifier's insertDeletedRun and insertMoveFromRun functions pack all collapsed field atoms into a single <w:r>, breaking multi-run field structure. This causes orphaned fldChar elements and leaked instrText that renders as visible text in Word.

Root Cause

Asymmetry in field handling between insert and delete paths:

• handleInserted (inPlaceModifier.ts): Correctly calls getAtomRuns(atom) and wraps each run individually — multi-run field structure preserved.
• handleDeleted → insertDeletedRun: Calls cloneRunWithAtomContent(sourceRun, atom) which clones only the FIRST run and packs ALL field elements into it.
• handleMovedSource → insertMoveFromRun: Same bug.

Observed Output (before fix)

<w:del>
  <w:r>
    <w:fldChar w:fldCharType="begin"/>
    <w:instrText> PAGEREF _Toc123 \h </w:instrText>
    <w:fldChar w:fldCharType="separate"/>
    <w:delText>23</w:delText>
    <w:fldChar w:fldCharType="end"/>
  </w:r>
</w:del>

Expected Output (after fix)

<w:del>
  <w:r><w:fldChar w:fldCharType="begin"/></w:r>
  <w:r><w:instrText> PAGEREF _Toc123 \h </w:instrText></w:r>
  <w:r><w:fldChar w:fldCharType="separate"/></w:r>
  <w:r><w:delText>23</w:delText></w:r>
  <w:r><w:fldChar w:fldCharType="end"/></w:r>
</w:del>

Fix

Added filterRun parameter to getInsertableAtomContentElements (Approach A). Both insertDeletedRun and insertMoveFromRun now call getAtomRuns() and emit one cloned run per original source run.

Tests

Regression tests in collapsed-field-inplace.test.ts:

• Dedicated-run field (PAGEREF): 6 tests
• Mixed-run field (REF with surrounding text): 4 tests
• Edge cases: 1 test