Reword the attrs=empty and language-placement refusals, quoting a language that needs it

src/markdown/empty-keys.ts

@@ -27,6 +27,6 @@ export function readEmptyKeys(type: string, attributes: DirectiveAttributes, key
     empty.add(key)
     rest.delete(key)
   }
-  if (empty.has('attrs') && (held || [...rest.keys()].some((key) => key !== 'marks'))) return { fault: unsupportedNodeShape(`${type} spells attrs=empty beside another attribute, an argument or content: drop attrs=empty or the rest`) }
+  if (empty.has('attrs') && (held || [...rest.keys()].some((key) => key !== 'marks'))) return { fault: unsupportedNodeShape(`${type} spells attrs=empty beside another attribute, an argument or a [content] slot: drop attrs=empty, or the rest`) }
   return { value: { empty, rest } }
 }

src/markdown/parse/markdown-to-adf.test.ts

@@ -166,7 +166,11 @@ test('reads the codeBlock directive body as the node content, the info string it
 
 test('names the slot a codeBlock spells its language outside of', () => {
   const slot = 'unsupported-node-shape: codeBlock spells its language in the fence info string, or in the attribute where no info string carries it back'
-  assert.equal(content(markdownToAdf('!adf:codeBlock {language=rust wrap=true}\n```\nx\n```\n!adf:/codeBlock\n')), "unsupported-node-shape: move language=rust to the fence's info string: a fence carries the language wherever its info string can")
+  assert.equal(content(markdownToAdf('!adf:codeBlock {language=rust wrap=true}\n```\nx\n```\n!adf:/codeBlock\n')), "unsupported-node-shape: move language=rust to the fences' info strings: they can spell this language")
+  assert.equal(
+    content(markdownToAdf('!adf:codeBlock {language="c sharp"}\n```\nx\n```\n```\ny\n```\n!adf:/codeBlock\n')),
+    "unsupported-node-shape: move language=\"c sharp\" to the fences' info strings: they can spell this language",
+  )
   assert.equal(content(markdownToAdf('!adf:codeBlock {language=rust}\n```sql\nx\n```\n!adf:/codeBlock\n')), slot)
   assert.equal(content(markdownToAdf('!adf:codeBlock {wrap=true}\n```adf:x\nx\n```\n!adf:/codeBlock\n')), slot)
   assert.equal(content(markdownToAdf('!adf:codeBlock {wrap=true}\n```a\\b\nx\n```\n!adf:/codeBlock\n')), slot)
@@ -1116,6 +1120,6 @@ test('leads a refusal ordinary editing meets with the edit that fixes it', () =>
   )
   assert.equal(
     content(markdownToAdf('!adf:panel info {attrs=empty}\nText.\n!adf:/panel\n')),
-    'unsupported-node-shape: panel spells attrs=empty beside another attribute, an argument or content: drop attrs=empty or the rest',
+    'unsupported-node-shape: panel spells attrs=empty beside another attribute, an argument or a [content] slot: drop attrs=empty, or the rest',
   )
 })

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

@@ -18,8 +18,8 @@ import { mintTaskIds } from './task-ids.ts'
 import { parseBlocks } from './blocks.ts'
 import { parseInlineContent } from './inline-content.ts'
 import { readBlockDirectiveNode } from './directive-nodes.ts'
+import { spellStringAttribute, unsupportedNodeShape } from '../directive-syntax.ts'
 import { spellsEmpty } from '../empty-keys.ts'
-import { unsupportedNodeShape } from '../directive-syntax.ts'
 
 type Paragraph = Extract<Block, { kind: 'paragraph' }>
 
@@ -257,7 +257,7 @@ function codeDirectiveNode(node: AdfNode, blocks: readonly Block[], path: Conver
   const fromFence = first.language !== ''
   const slot = languageSlot(fromFence ? first.language : attribute)
   if (!fromFence && slot.kind === 'fence') {
-    return failure('unsupported-node-shape', `move language=${slot.info} to the fence's info string: a fence carries the language wherever its info string can`, path)
+    return failure('unsupported-node-shape', `move language=${spellStringAttribute(slot.info)} to the fences' info strings: they can spell this language`, path)
   }
   if ((slot.kind === 'fence') !== fromFence || (fromFence && attribute !== undefined)) {
     return failure('unsupported-node-shape', `${node.type} spells its language in the fence info string, or in the attribute where no info string carries it back`, path)