Keep one merge loop and one mark key: editor-normal compares normalized marks with identicalMark

src/adf/document.ts

@@ -68,8 +68,22 @@ export function identicalMark(left: AdfMark, right: AdfMark): boolean {
   return marksKey([left]) === marksKey([right])
 }
 
-export function identicalMarks(left: AdfNode, right: AdfNode): boolean {
-  return marksKey(nodeMarks(left)) === marksKey(nodeMarks(right))
+export function identicalMarks(left: readonly AdfMark[], right: readonly AdfMark[]): boolean {
+  return marksKey(left) === marksKey(right)
+}
+
+// `joins` is the caller's: a reader joins what CommonMark reads as one, editor-normal ADF what the editor would.
+export function mergeAdjacentText(nodes: readonly AdfNode[], joins: (previous: AdfNode, node: AdfNode) => boolean): AdfNode[] {
+  const merged: AdfNode[] = []
+  for (const node of nodes) {
+    const previous = merged[merged.length - 1]
+    if (previous !== undefined && joins(previous, node)) {
+      merged[merged.length - 1] = { ...previous, text: `${previous.text ?? ''}${node.text ?? ''}` }
+      continue
+    }
+    merged.push(node)
+  }
+  return merged
 }
 
 // Depth is the walks' business, not the shape's: the guard waves a deep document through as blocks and marks do.

src/adf/editor-normal.ts

@@ -1,34 +1,25 @@
 import type { AdfAttributes, AdfDocument, AdfMark, AdfNode } from './document.ts'
 import type { JsonValue } from '../json-value.ts'
-import { nodeAttrs, nodeContent, nodeMarks } from './document.ts'
-import { serializeCanonicalJson } from '../canonical-json.ts'
+import { identicalMark, identicalMarks, mergeAdjacentText, nodeAttrs, nodeContent, nodeMarks } from './document.ts'
 
 type JsonContainer = JsonValue[] | { [key: string]: JsonValue }
 
 type NodeHolder = { content?: AdfNode[] }
 
-export function sameMark(candidate: AdfMark, mark: AdfMark): boolean {
-  return markKey(candidate) === markKey(mark)
+export function sameMark(left: AdfMark, right: AdfMark): boolean {
+  return identicalMark(normalMark(left), normalMark(right))
 }
 
-export function mergeAdjacentText(nodes: readonly AdfNode[]): AdfNode[] {
-  const merged: AdfNode[] = []
-  for (const node of nodes) {
-    const previous = merged[merged.length - 1]
-    if (previous !== undefined && mergesText(previous) && mergesText(node) && sameMarks(previous, node)) {
-      merged[merged.length - 1] = { ...previous, text: `${previous.text ?? ''}${node.text ?? ''}` }
-      continue
-    }
-    merged.push(node)
-  }
-  return merged
+export function joinsNormally(previous: AdfNode, node: AdfNode): boolean {
+  if (!mergesText(previous) || !mergesText(node)) return false
+  return identicalMarks(nodeMarks(previous).map(normalMark), nodeMarks(node).map(normalMark))
 }
 
 export function toEditorNormal(document: AdfDocument): AdfDocument {
   const normal: AdfDocument = { type: document.type, version: Object.is(document.version, -0) ? 0 : document.version }
   const pending: { holder: NodeHolder; source: NodeHolder }[] = [{ holder: normal, source: document }]
   for (let entry = pending.pop(); entry !== undefined; entry = pending.pop()) {
-    const content = mergeAdjacentText(nodeContent(entry.source))
+    const content = mergeAdjacentText(nodeContent(entry.source), joinsNormally)
     if (content.length === 0) continue
     entry.holder.content = content.map((source) => {
       const holder = normalNode(source)
@@ -76,15 +67,3 @@ function normalValue(value: JsonValue, pending: JsonContainer[]): JsonValue {
 function mergesText(node: AdfNode): boolean {
   return node.type === 'text' && Object.keys(nodeAttrs(node)).length === 0
 }
-
-function sameMarks(previous: AdfNode, node: AdfNode): boolean {
-  return marksKey(nodeMarks(previous)) === marksKey(nodeMarks(node))
-}
-
-function marksKey(marks: readonly AdfMark[]): string {
-  return marks.map(markKey).join('\n')
-}
-
-function markKey(mark: AdfMark): string {
-  return `${mark.type} ${serializeCanonicalJson(normalAttributes(nodeAttrs(mark)) ?? {}, 'compact')}`
-}

src/conformance/property-harness.ts

@@ -10,8 +10,9 @@ import { blockArgument } from '../markdown/block-directive.ts'
 import { blockNodes } from '../adf/block-nodes.ts'
 import { directivePrefix } from '../markdown/directive-syntax.ts'
 import { inlineNodes } from '../adf/inline-nodes.ts'
+import { joinsNormally } from '../adf/editor-normal.ts'
 import { markAttributes } from '../adf/mark-attributes.ts'
-import { mergeAdjacentText } from '../adf/editor-normal.ts'
+import { mergeAdjacentText } from '../adf/document.ts'
 
 type Positions = { block: AdfNode; inline: AdfNode }
 
@@ -92,7 +93,7 @@ function withoutEmptyKeys<T extends AdfMark | AdfNode>(held: T): T {
 }
 
 function occasionallyApart(arbitrary: Arbitrary<AdfNode[]>): Arbitrary<AdfNode[]> {
-  return fc.tuple(arbitrary, fc.nat({ max: 5 })).map(([nodes, roll]) => (roll === 0 ? nodes : mergeAdjacentText(nodes)))
+  return fc.tuple(arbitrary, fc.nat({ max: 5 })).map(([nodes, roll]) => (roll === 0 ? nodes : mergeAdjacentText(nodes, joinsNormally)))
 }
 
 function pipeTable({ body, header }: { body: AdfNode[][]; header: AdfNode[] }): AdfNode {

src/markdown/emit/plain-inline.ts

@@ -3,9 +3,9 @@ import type { LineContainer } from '../line-container.ts'
 import type { MarkRun } from './line-escaping.ts'
 import { blockNodeModel } from '../../adf/block-nodes.ts'
 import { failure, success, type ConvertErrorPath, type Result } from '../../result.ts'
+import { joinsNormally, sameMark } from '../../adf/editor-normal.ts'
 import { largestNesting } from '../../nesting.ts'
-import { mergeAdjacentText, sameMark } from '../../adf/editor-normal.ts'
-import { nodeAttrs, nodeContent, nodeMarks } from '../../adf/document.ts'
+import { mergeAdjacentText, nodeAttrs, nodeContent, nodeMarks } from '../../adf/document.ts'
 import { plainLineFallback, type PlainLineFallback } from './inline-line.ts'
 import { spellDestination, spellLinkTarget } from '../commonmark/link-syntax.ts'
 
@@ -193,7 +193,7 @@ function withMarks(leaf: AdfNode, marks: readonly AdfMark[]): AdfNode {
 
 function trimmedEdges(leaves: readonly AdfNode[]): AdfNode[] {
   for (let current = leaves; ; ) {
-    const merged = withoutEdgeBreaks(mergeAdjacentText(current))
+    const merged = withoutEdgeBreaks(mergeAdjacentText(current, joinsNormally))
     let changed = false
     const trimmed: AdfNode[] = []
     for (const [index, leaf] of merged.entries()) {

src/markdown/parse/inline-content.ts

@@ -10,7 +10,7 @@ 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 { highlightDelimiter, highlightFlanking } from '../plain-conventions.ts'
-import { identicalMarks, nodeAttrs, nodeMarks } from '../../adf/document.ts'
+import { identicalMarks, mergeAdjacentText, nodeAttrs, nodeMarks } from '../../adf/document.ts'
 import { inlineNodeModel } from '../../adf/inline-nodes.ts'
 import { noSpans, readInlineDirective } from '../directive-syntax.ts'
 import { normalizeLabel, readInlineTarget, readLabel } from '../commonmark/link-syntax.ts'
@@ -475,20 +475,7 @@ function resolveNodes(pieces: readonly Piece[], scan: Scan, highlights: boolean)
   writeUnpaired(nodes, runs, pairings)
   if (!markPairings(pieces, nodes, pairings)) return failure('unsupported-node-shape', carriedInMark, scan.path)
   markHighlights(pieces, nodes, highlights ? pairedHighlights(pieces, nodes) : [])
-  return success(mergeText(nodes.flat(), scan.carried))
-}
-
-function mergeText(nodes: readonly AdfNode[], carried: ReadonlySet<AdfNode>): AdfNode[] {
-  const merged: AdfNode[] = []
-  for (const node of nodes) {
-    const previous = merged[merged.length - 1]
-    if (previous !== undefined && !carried.has(previous) && !carried.has(node) && readsAsOne(previous, node)) {
-      merged[merged.length - 1] = { ...previous, text: `${previous.text ?? ''}${node.text ?? ''}` }
-      continue
-    }
-    merged.push(node)
-  }
-  return merged
+  return success(mergeAdjacentText(nodes.flat(), (previous, node) => !scan.carried.has(previous) && !scan.carried.has(node) && readsAsOne(previous, node)))
 }
 
 // Only `imageAlt` reaches the image arm: everywhere else an image amid other content is refused first.
@@ -579,7 +566,7 @@ function pairedHighlights(pieces: readonly Piece[], nodes: readonly AdfNode[][])
     let candidate = found[closer]
     while (candidate !== undefined && (!candidate.closes || candidate.position < earliest)) candidate = found[(closer += 1)]
     if (candidate === undefined) break
-    if (candidate.line !== opener.line || !identicalMarks(opener.holder, candidate.holder)) continue
+    if (candidate.line !== opener.line || !identicalMarks(nodeMarks(opener.holder), nodeMarks(candidate.holder))) continue
     paired.push({ closer: candidate.index, opener: opener.index })
     resume = candidate.position + highlightDelimiter.length
   }

src/markdown/text-break.ts

@@ -1,5 +1,5 @@
 import type { AdfNode } from '../adf/document.ts'
-import { identicalMarks } from '../adf/document.ts'
+import { identicalMarks, nodeMarks } from '../adf/document.ts'
 import { spellInlineLeafDirective } from './directive-syntax.ts'
 
 export const textBreakName = 'textBreak'
@@ -8,7 +8,7 @@ export const textBreakSpelling = spellInlineLeafDirective(textBreakName, '')
 
 // Whether CommonMark reads the pair back as one text node, where neither rides the carry (spec/flavour.md, Inline nodes).
 export function readsAsOne(previous: AdfNode, node: AdfNode): boolean {
-  return spelledAsText(previous) && spelledAsText(node) && identicalMarks(previous, node)
+  return spelledAsText(previous) && spelledAsText(node) && identicalMarks(nodeMarks(previous), nodeMarks(node))
 }
 
 function spelledAsText(node: AdfNode): boolean {