AGENTS.md

@@ -163,10 +163,10 @@ shape, and threading a path to the ninth — a malformed node anywhere in the tr
 manual stack §11's no-recursion rule forces, whose empty half no input reaches. The message names
 the violation instead. Depth is not one of the nine: `adfDocumentFault` returns the code with the
 message, so an attribute value past 500 levels is `unsupported-nesting-depth` from the emitter as
-it already is from the parser, both directions refusing the same value. A node's attribute is
-counted from the value itself, never from the `attrs` object holding it; a mark's is counted three
-levels in, because the block directive spells the whole mark set as one JSON attribute and the
-parser reads the value at the bottom of array, mark and `attrs`. `isAdfDocument` is true for a depth fault:
+it already is from the parser, both directions refusing the same value. An attribute, a node's or
+a mark's, is counted from the value itself, never from the `attrs` object holding it; a spelling
+nesting the value deeper — the block directive's marks attribute, three levels in, or the carry —
+refuses in its own format, as that format's parser does. `isAdfDocument` is true for a depth fault:
 a deep document is a document, as the 2000-level blocks and the 600-deep marks the guard already
 waves through are, and depth is the walks' answer rather than the shape's. A non-finite number
 stays parted where depth is joined: the parse says `unsupported-node-shape` because the markdown is

src/adf/document.test.ts

@@ -68,9 +68,9 @@ test('names the attribute nesting past the levels the parser reads one at, and s
   assert.equal(faultCode(withAttribute(nested(largestNesting + 1))), 'unsupported-nesting-depth')
   assert.equal(isAdfDocument(withAttribute(nested(largestNesting + 1))), true)
   const marked = (levels: number): unknown => ({ content: [{ marks: [{ attrs: { a: nested(levels) }, type: 'link' }], text: 'x', type: 'text' }], type: 'doc', version: 1 })
-  assert.equal(fault(marked(largestNesting - 3)), 'accepted')
-  assert.equal(fault(marked(largestNesting - 2)), deeper('a', 'link', largestNesting - 3))
-  assert.equal(isAdfDocument(marked(largestNesting - 2)), true)
+  assert.equal(fault(marked(largestNesting)), 'accepted')
+  assert.equal(fault(marked(largestNesting + 1)), deeper('a', 'link'))
+  assert.equal(isAdfDocument(marked(largestNesting + 1)), true)
 })
 
 test('accepts the JSON values an attribute may hold', () => {

src/adf/document.ts

@@ -23,9 +23,6 @@ export type AdfDocument = {
   version: number
 }
 
-// A block directive spells the whole mark set as one JSON attribute, so a mark's value sits three levels inside it.
-const markAttributeNesting = largestNesting - 3
-
 const documentKeys = ['content', 'type', 'version']
 const markKeys = ['attrs', 'type']
 const nodeKeys = ['attrs', 'content', 'marks', 'text', 'type']
@@ -47,8 +44,8 @@ export function adfDocumentFault(value: unknown): ConvertFault | undefined {
   return nestingFault(content)
 }
 
-export function attributeNestingMessage(key: string, type: string, levels: number = largestNesting): string {
-  return `the ${key} attribute of ${type} nests deeper than the ${levels} levels an attribute carries`
+export function attributeNestingMessage(key: string, type: string): string {
+  return `the ${key} attribute of ${type} nests deeper than the ${largestNesting} levels an attribute carries`
 }
 
 export function carriesOnly(node: AdfNode, attributes: readonly string[]): boolean {
@@ -116,15 +113,15 @@ function nestingFault(nodes: readonly AdfNode[]): ConvertFault | undefined {
 
 function marksFault(marks: readonly AdfMark[]): ConvertFault | undefined {
   for (const mark of marks) {
-    const fault = attributesFault(nodeAttrs(mark), mark.type, markAttributeNesting)
+    const fault = attributesFault(nodeAttrs(mark), mark.type)
     if (fault !== undefined) return fault
   }
   return undefined
 }
 
-function attributesFault(attrs: AdfAttributes, type: string, levels: number = largestNesting): ConvertFault | undefined {
+function attributesFault(attrs: AdfAttributes, type: string): ConvertFault | undefined {
   for (const [key, value] of Object.entries(attrs)) {
-    if (overNested(value, levels)) return { code: 'unsupported-nesting-depth', message: attributeNestingMessage(key, type, levels) }
+    if (overNested(value)) return { code: 'unsupported-nesting-depth', message: attributeNestingMessage(key, type) }
   }
   return undefined
 }

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

@@ -375,11 +375,16 @@ test('refuses marks and attributes nested deeper than the emitter carries', () =
     assert.deepEqual(toEditorNormal(read.value), document(node))
   }
 
-  assert.equal(markdown(adfToMarkdown(document(paragraph({ marks: [{ attrs, type: 'em' }], text: 'x', type: 'text' })))), deeper('depth', 'em', largestNesting - 3))
+  assert.equal(markdown(adfToMarkdown(document(paragraph({ marks: [{ attrs, type: 'em' }], text: 'x', type: 'text' })))), deeper('depth', 'em'))
+  assert.equal(
+    markdown(adfToMarkdown(document(paragraph({ marks: [{ attrs: { deep: nested(largestNesting) }, type: 'em' }], text: 'x', type: 'text' })))),
+    `unsupported-nesting-depth: a carried node's JSON nests deeper than the ${largestNesting} levels its position leaves`,
+  )
   assert.equal(markdown(adfToMarkdown(document(paragraph(card(largestNesting + 1))))), deeper('data', 'inlineCard'))
   assert.deepEqual(path(adfToMarkdown(document(paragraph(card(largestNesting + 1))))), [])
   roundTrips(paragraph(card(largestNesting)))
-  assert.equal(markdown(adfToMarkdown(document(marked(largestNesting - 2)))), deeper('deep', 'em', largestNesting - 3))
+  assert.equal(markdown(adfToMarkdown(document(marked(largestNesting - 2)))), deeper('marks', 'panel'))
+  assert.deepEqual(path(adfToMarkdown(document(marked(largestNesting - 2)))), ['content', 0])
   roundTrips(marked(largestNesting - 3))
 })
 

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

@@ -147,9 +147,10 @@ function emitDirectiveBlock(node: AdfNode, model: BlockNodeModel, path: ConvertE
   if (node.text !== undefined) return failure('unsupported-node-shape', `a ${node.type} carries no text: this one holds text`, path)
   if (blockDirectiveForm(node.type) === 'leaf' && nodeContent(node).length > 0) return failure('unsupported-node-shape', `a ${node.type} holds no content: this one holds some`, path)
   if (model.contentModel === 'code') return emitCodeDirective(node, model, path, depth)
-  const opener = spellBlockDirectiveOpener(node, model)
+  const opener = spellBlockDirectiveOpener(node, model, path)
   if (opener === undefined) return commonMarkLine(carriedBlock(node, path, depth))
-  return emitDirectiveBody(node, model, opener, path, walkBody)
+  if (!opener.ok) return opener
+  return emitDirectiveBody(node, model, opener.value, path, walkBody)
 }
 
 function emitDirectiveBody(node: AdfNode, model: BlockNodeModel, opener: string, path: ConvertErrorPath, walkBody: () => Result<Walk>): Result<EmittedBlock> {
@@ -186,11 +187,12 @@ function tryCodeBlock(node: AdfNode, path: ConvertErrorPath): Result<EmittedBloc
 
 function emitCodeDirective(node: AdfNode, model: BlockNodeModel, path: ConvertErrorPath, depth: number): Result<EmittedBlock> {
   const slot = languageSlot(nodeAttrs(node)['language'])
-  const opener = spellBlockDirectiveOpener(node, model, slot.kind === 'attribute' ? [] : ['language'])
+  const opener = spellBlockDirectiveOpener(node, model, path, slot.kind === 'attribute' ? [] : ['language'])
   if (opener === undefined) return commonMarkLine(carriedBlock(node, path, depth))
+  if (!opener.ok) return opener
   const text = codeBlockText(node, path)
   if (!text.ok) return text
-  return success(directivePair(node, opener, fencedCodeBlock(slot.kind === 'fence' ? slot.info : '', text.value)))
+  return success(directivePair(node, opener.value, fencedCodeBlock(slot.kind === 'fence' ? slot.info : '', text.value)))
 }
 
 function codeBlockText(node: AdfNode, path: ConvertErrorPath): Result<string> {

src/markdown/emit/block-directive-spelling.ts

@@ -1,12 +1,14 @@
 import type { AdfNode } from '../../adf/document.ts'
 import type { BlockNodeModel } from '../../adf/block-nodes.ts'
+import { attributeNestingMessage, nodeAttrs, nodeMarks } from '../../adf/document.ts'
 import { blockArgument } from '../block-directive-arguments.ts'
+import { failure, success, type ConvertErrorPath, type Result } from '../../result.ts'
 import { isBareToken, spellAttributes, spellDirectiveOpener, spellJsonAttribute, spellVocabulary } from '../directive-syntax.ts'
 import { markValues, marksAttribute } from '../block-directive-marks.ts'
-import { nodeAttrs, nodeMarks } from '../../adf/document.ts'
+import { overNested } from '../../json-value.ts'
 import { vocabularyPairs } from '../../adf/attribute-vocabulary.ts'
 
-export function spellBlockDirectiveOpener(node: AdfNode, model: BlockNodeModel, spelledByBody: readonly string[] = []): string | undefined {
+export function spellBlockDirectiveOpener(node: AdfNode, model: BlockNodeModel, path: ConvertErrorPath, spelledByBody: readonly string[] = []): Result<string> | undefined {
   const argumentAttribute = blockArgument(node.type)
   const slot = bareArgument(node, argumentAttribute)
   if (slot === undefined) return undefined
@@ -15,8 +17,12 @@ export function spellBlockDirectiveOpener(node: AdfNode, model: BlockNodeModel,
   if (pairs === undefined) return undefined
   const spelledPairs = spellVocabulary(pairs)
   const marks = nodeMarks(node)
-  if (marks.length > 0) spelledPairs.push([marksAttribute, spellJsonAttribute(markValues(marks))])
-  return spellDirectiveOpener(node.type, slot.argument, spellAttributes(spelledPairs))
+  if (marks.length > 0) {
+    const values = markValues(marks)
+    if (overNested(values)) return failure('unsupported-nesting-depth', attributeNestingMessage(marksAttribute, node.type), path)
+    spelledPairs.push([marksAttribute, spellJsonAttribute(values)])
+  }
+  return success(spellDirectiveOpener(node.type, slot.argument, spellAttributes(spelledPairs)))
 }
 
 // `undefined` where the argument slot holds a value no bare token spells.