Give the unmarked bare text check and the text-holding-content refusal one owner each

src/adf/document.ts

@@ -69,6 +69,10 @@ export function isBareText(node: AdfNode): boolean {
   return node.type === 'text' && node.attrs === undefined && node.content === undefined && node.marks?.length !== 0
 }
 
+export function isUnmarkedBareText(node: AdfNode): boolean {
+  return isBareText(node) && node.marks === undefined
+}
+
 export function identicalMark(left: AdfMark, right: AdfMark): boolean {
   return marksKey([left]) === marksKey([right])
 }

src/markdown/emit/adf-to-markdown.ts

@@ -1,7 +1,7 @@
 import type { AdfDocument, AdfNode } from '../../adf/document.ts'
 import type { BlockNodeModel } from '../../adf/block-nodes.ts'
 import type { Flavour } from '../plain/conventions.ts'
-import { adfDocumentFault, holdsOnlyAttributes, isBareText, nodeAttrs, nodeContent } from '../../adf/document.ts'
+import { adfDocumentFault, holdsOnlyAttributes, isUnmarkedBareText, nodeAttrs, nodeContent } from '../../adf/document.ts'
 import { alertMarker, foldedAlertMarker, leadingMarker, readAlertMarker, readTaskMarker, taskMarker } from '../plain/conventions.ts'
 import { blockDirectiveForm, documentSpelling, listBreakSpelling } from '../block-directive.ts'
 import { blockNodeModel, blockNodes } from '../../adf/block-nodes.ts'
@@ -278,7 +278,7 @@ function emitCodeDirective(node: AdfNode, model: BlockNodeModel, path: ConvertEr
 // The text each fence holds, or `undefined` where a child is no plain text node, which the carry holds instead.
 function fencedTexts(node: AdfNode, path: ConvertErrorPath): Result<string[] | undefined> {
   if (node.content === undefined) return success([''])
-  if (node.content.some((child) => !isBareText(child) || child.marks !== undefined)) return success(undefined)
+  if (node.content.some((child) => !isUnmarkedBareText(child))) return success(undefined)
   const texts: string[] = []
   for (const [index, child] of node.content.entries()) {
     const childPath = [...path, 'content', index]

src/markdown/emit/inline-line.ts

@@ -267,8 +267,13 @@ function emitInlineDirective(node: AdfNode, model: InlineNodeModel, index: numbe
   return success({ segments: [syntax(spellInlineDirectiveOpener(node.type)), ...content, syntax(`]${attributes}`)] })
 }
 
+function textHoldingContent(node: AdfNode, path: ConvertErrorPath): Result<never> | undefined {
+  return node.type === 'text' && nodeContent(node).length > 0 ? failure('unsupported-node-shape', 'a text node holds no content: this one holds some', path) : undefined
+}
+
 function emitText(node: AdfNode, context: InlineContext, index: number, path: ConvertErrorPath): Result<Emission> {
-  if (nodeContent(node).length > 0) return failure('unsupported-node-shape', 'a text node holds no content: this one holds some', path)
+  const holding = textHoldingContent(node, path)
+  if (holding !== undefined) return holding
   if (!isBareText(node)) return success({ carry: { first: index, last: index } })
   if (typeof node.text !== 'string' || node.text === '') return failure('unsupported-node-shape', 'a text node holds text: this one has none', path)
   if (/\r/.test(node.text)) return failure('unspellable-character', 'a text node holds a carriage return CommonMark rewrites', path)
@@ -323,7 +328,8 @@ function emitHighlight(nodes: readonly AdfNode[], depth: number, range: NodeRang
 function emitCodeSpan(nodes: readonly AdfNode[], depth: number, range: NodeRange, path: ConvertErrorPath): Result<Emission> {
   const spans: string[] = []
   for (const node of nodes) {
-    if (node.type === 'text' && nodeContent(node).length > 0) return failure('unsupported-node-shape', 'a text node holds no content: this one holds some', path)
+    const holding = textHoldingContent(node, path)
+    if (holding !== undefined) return holding
     if (!isBareText(node) || nodeMarks(node).length !== depth + 1) return success({ carry: range })
     const { text } = node
     if (typeof text !== 'string' || text === '') return failure('unsupported-node-shape', 'a text node holds text: this one has none', path)

src/markdown/parse/directive-nodes.ts

@@ -3,7 +3,7 @@ import type { BlockNodeModel } from '../../adf/block-nodes.ts'
 import type { ConvertFault } from '../../result.ts'
 import type { DirectiveAttributes, DirectiveValue } from '../directive-syntax.ts'
 import type { Elsewhere } from './directive-attributes.ts'
-import { attributeNestingMessage, isBareText } from '../../adf/document.ts'
+import { attributeNestingMessage, isUnmarkedBareText } from '../../adf/document.ts'
 import { attributeValue, directivePrefix, spellAttributeValue, unknownDirectiveFault } from '../directive-syntax.ts'
 import { blockArgument, blockDirectiveForm, marksAttribute, readMarkValues } from '../block-directive.ts'
 import { blockNodeModel } from '../../adf/block-nodes.ts'
@@ -92,7 +92,7 @@ function blockSpellingFault(name: string): ConvertFault | undefined {
 function slotText(content: readonly AdfNode[]): string | undefined {
   if (content.length === 0) return ''
   const only = content.length === 1 ? content[0] : undefined
-  if (only === undefined || !isBareText(only) || only.marks !== undefined || typeof only.text !== 'string') return undefined
+  if (only === undefined || !isUnmarkedBareText(only) || typeof only.text !== 'string') return undefined
   return only.text
 }