15 - refuse the directive link spelling no href, so the mark has one spelling

src/markdown/emit/inline-line.ts

@@ -3,7 +3,7 @@ import type { InlineDirective } from '../../adf/inline-directives.ts'
 import { assembleInlineLine, isSyntax, type InlineEscaping, type InlineSegment, type LineContainer, type NodeRange } from './line-escaping.ts'
 import { carriedInline } from '../opaque-carry.ts'
 import { claimsLine, holdsNullCharacter, trimTrailingSpace } from '../commonmark/grammar.ts'
-import { commonMarkLink, markSpelling, spellMarkAttributes } from '../mark-spellings.ts'
+import { commonMarkLink, linkHref, markSpelling, spellMarkAttributes } from '../mark-spellings.ts'
 import { escapeUnbalanced, spellDestination } from '../commonmark/link-syntax.ts'
 import { failure, faulted, success, type ConvertErrorPath, type Result } from '../../result.ts'
 import { inlineDirective } from '../../adf/inline-directives.ts'
@@ -300,8 +300,8 @@ function needsPadding(text: string): boolean {
 
 // `undefined` where the link takes the directive form the caller spells.
 function emitLink(nodes: readonly AdfNode[], mark: AdfMark, depth: number, range: NodeRange, context: InlineContext): Result<Emission> | undefined {
-  const href = nodeAttrs(mark)['href']
-  if (typeof href !== 'string') return success({ carry: range })
+  const href = linkHref(nodeAttrs(mark))
+  if (href === undefined) return success({ carry: range })
   const opening = depth === 0 && range.first === 0 && context.openingLinkAsDirective
   const commonMark = opening ? undefined : commonMarkLink(nodeAttrs(mark), href, nodes, depth + 1, context.bracketed)
   if (commonMark === undefined) return undefined

src/markdown/mark-spellings.ts

@@ -35,6 +35,11 @@ export function markSpelling(type: string): MarkSpelling | undefined {
   return { attributes, kind: spelling.kind }
 }
 
+export function linkHref(attrs: AdfAttributes): string | undefined {
+  const href = attrs['href']
+  return typeof href === 'string' ? href : undefined
+}
+
 // spec/flavour.md, Marks. `marksInside` counts the marks the link's nodes carry within it: the emitter's depth + 1, the parser's 0.
 export function commonMarkLink(attrs: AdfAttributes, href: string, nodes: readonly AdfNode[], marksInside: number, bracketed: boolean): CommonMarkLink | undefined {
   if (Object.keys(attrs).some((key) => key !== 'href' && key !== 'title')) return undefined

src/markdown/parse/inline-content.ts

@@ -5,7 +5,7 @@ import type { LineContainer } from '../emit/line-escaping.ts'
 import type { LinkDefinition } from '../commonmark/link-syntax.ts'
 import { backslashEscape, decodeTextEscapes, inlineHtmlConstruct, readBracketedAutolink, readEmailAutolink, trimTrailingSpace } from '../commonmark/grammar.ts'
 import { backtickRun, closingBacktickRun } from '../commonmark/backtick-runs.ts'
-import { commonMarkLink } from '../mark-spellings.ts'
+import { commonMarkLink, linkHref } from '../mark-spellings.ts'
 import { delimiterFlags, matchEmphasis, runLength } from '../commonmark/emphasis-matching.ts'
 import { failure, faulted, success, type ConvertErrorPath, type Result } from '../../result.ts'
 import { inlineDirective } from '../../adf/inline-directives.ts'
@@ -51,6 +51,7 @@ type Scan = {
 type SlotContent = { carry: boolean; nodes: AdfNode[] }
 
 const carriedInMark = 'no mark spelling wraps an opaque carry: the carried node restores exactly, marks included'
+const hreflessLink = 'the link mark spells its href: this one spells none'
 const imageAlone = 'an image fits only as a paragraph of its own: this one sits inside other content'
 const spellableLink = 'link takes the directive form only where CommonMark cannot spell it: this one it can, as [text](url "title") or <url>'
 
@@ -208,15 +209,15 @@ function directiveMarkPiece(scan: Scan, name: string, mark: AdfMark, slot: SlotC
     return failure('unsupported-node-shape', `the ${name} mark wraps the [content] it marks: this one wraps none`, scan.path)
   }
   if (slot.carry) return failure('unsupported-node-shape', carriedInMark, scan.path)
-  const refused = mark.type === 'link' ? refuseSpellableLink(scan, mark, slot.nodes, index) : undefined
+  const refused = mark.type === 'link' ? refuseLinkDirective(scan, mark, slot.nodes, index) : undefined
   if (refused !== undefined) return refused
   return success({ kind: 'nodes', nodes: applyMark(slot.nodes, mark) })
 }
 
 // spec/flavour.md, Marks. A link opening a paragraph may still need the directive form for the line it opens, which `assemble` asks the emitter.
-function refuseSpellableLink(scan: Scan, mark: AdfMark, nodes: readonly AdfNode[], index: number): Result<Piece> | undefined {
-  const href = nodeAttrs(mark)['href']
-  if (typeof href !== 'string') return undefined
+function refuseLinkDirective(scan: Scan, mark: AdfMark, nodes: readonly AdfNode[], index: number): Result<Piece> | undefined {
+  const href = linkHref(nodeAttrs(mark))
+  if (href === undefined) return failure('unsupported-node-shape', hreflessLink, scan.path)
   if (commonMarkLink(nodeAttrs(mark), href, nodes, 0, scan.container === undefined) === undefined) return undefined
   if (index !== 0 || scan.container !== 'paragraph') return failure('unsupported-node-shape', spellableLink, scan.path)
   scan.openingSpellableLink = true

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

@@ -984,8 +984,6 @@ test('refuses the directive link CommonMark could spell, and reads the one it co
   assert.equal(content(markdownToAdf('| !adf:link[`]: a`]{href="/u"} |\n| --- |\n')), refused)
   assert.equal(content(markdownToAdf('!adf:underline[!adf:link[a]{href="/u"}]\n')), refused)
   assert.deepEqual(path(markdownToAdf('Part.\n\nSee !adf:link[a]{href="/u"}.\n')), ['content', 1])
-  const titled: AdfNode = { marks: [{ attrs: { title: 't' }, type: 'link' }], text: 'a', type: 'text' }
-  assert.deepEqual(content(markdownToAdf('!adf:link[a]{title=t}\n')), [{ content: [titled], type: 'paragraph' }])
   const opening: AdfNode = { marks: [{ attrs: { href: '/u' }, type: 'link' }, { type: 'code' }], text: ']: a', type: 'text' }
   assert.deepEqual(content(markdownToAdf('!adf:link[`]: a`]{href="/u"}\n')), [{ content: [opening], type: 'paragraph' }])
   assert.deepEqual(content(markdownToAdf('!adf:heading {level=1 localId=h}\n!adf:link[`]: a`]{href="/u"}\n!adf:/heading\n')), [
@@ -993,6 +991,15 @@ test('refuses the directive link CommonMark could spell, and reads the one it co
   ])
 })
 
+test('names the href the directive link spells no value for', () => {
+  const named = 'unsupported-node-shape: the link mark spells its href: this one spells none'
+  assert.equal(content(markdownToAdf('!adf:link[a]\n')), named)
+  assert.equal(content(markdownToAdf('!adf:link[a]{title=t}\n')), named)
+  assert.equal(content(markdownToAdf('See !adf:link[a]{id=01a032c3-7a90-70c9-88f6-c60f710eda07}.\n')), named)
+  assert.equal(content(markdownToAdf('!adf:underline[!adf:link[a]{title=t}]\n')), named)
+  assert.deepEqual(path(markdownToAdf('Part.\n\nSee !adf:link[a]{title=t}.\n')), ['content', 1])
+})
+
 test('names the directive mark left without the content it wraps', () => {
   const named = 'unsupported-node-shape: the underline mark wraps the [content] it marks: this one wraps none'
   assert.equal(content(markdownToAdf('!adf:underline[]\n')), named)