5c: match the mark set's nesting on both sides of the round-trip

src/adf/document.test.ts

@@ -61,14 +61,16 @@ test('rejects a node whose shape ProseMirror JSON cannot hold', () => {
 })
 
 test('names the attribute nesting past the levels the parser reads one at, and still calls the value a document', () => {
-  const deeper = (key: string, type: string): string => `the ${key} attribute of ${type} nests deeper than the ${largestNesting} levels an attribute carries`
+  const deeper = (key: string, type: string, levels: number = largestNesting): string =>
+    `the ${key} attribute of ${type} nests deeper than the ${levels} levels an attribute carries`
   assert.equal(fault(withAttribute(nested(largestNesting))), 'accepted')
   assert.equal(fault(withAttribute(nested(largestNesting + 1))), deeper('a', 'paragraph'))
   assert.equal(faultCode(withAttribute(nested(largestNesting + 1))), 'unsupported-nesting-depth')
   assert.equal(isAdfDocument(withAttribute(nested(largestNesting + 1))), true)
-  const marked = { content: [{ marks: [{ attrs: { a: nested(largestNesting + 1) }, type: 'link' }], text: 'x', type: 'text' }], type: 'doc', version: 1 }
-  assert.equal(fault(marked), deeper('a', 'link'))
-  assert.equal(isAdfDocument(marked), 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)
 })
 
 test('accepts the JSON values an attribute may hold', () => {