4.1: a text node carrying attributes never merges

AGENTS.md

@@ -23,8 +23,8 @@ backticks read back as a fence — so a parse succeeding does not imply a spella
 `corpus/commonmark-spec/exceptions.json` names those.
 
 "Equals" is structural equality over editor-normal ADF — adjacent text nodes with identical marks
-merged, JSON number semantics, an empty attrs object, marks array or content array the absent
-key — the only domain markdown can restore.
+and no attributes merged, JSON number semantics, an empty attrs object, marks array or content
+array the absent key — the only domain markdown can restore.
 
 Round-trip equality is a property tested over a corpus, not a claim made in prose.
 

corpus/round-trip/combinations/carry-text-attributes.json

@@ -0,0 +1,76 @@
+{
+  "content": [
+    {
+      "content": [
+        {
+          "attrs": {
+            "localId": "01a0a067-68cf-78af-abd6-c660ec0d189b"
+          },
+          "text": "Owner",
+          "type": "text"
+        },
+        {
+          "text": " signs off.",
+          "type": "text"
+        }
+      ],
+      "type": "paragraph"
+    },
+    {
+      "content": [
+        {
+          "text": "Signed by ",
+          "type": "text"
+        },
+        {
+          "attrs": {
+            "localId": "01a0a067-68d2-787e-afc5-2459776aa029"
+          },
+          "text": "the owner",
+          "type": "text"
+        }
+      ],
+      "type": "paragraph"
+    },
+    {
+      "content": [
+        {
+          "attrs": {
+            "localId": "01a0a067-68d5-7372-9962-29a039654056"
+          },
+          "text": "One ",
+          "type": "text"
+        },
+        {
+          "attrs": {
+            "localId": "01a0a067-68d5-7372-9962-29a039654056"
+          },
+          "text": "anchor",
+          "type": "text"
+        }
+      ],
+      "type": "paragraph"
+    },
+    {
+      "content": [
+        {
+          "attrs": {
+            "localId": "01a0a067-68cf-78af-abd6-c660ec0d189b"
+          },
+          "text": "Two ",
+          "type": "text"
+        },
+        {
+          "attrs": {
+            "localId": "01a0a067-68d9-73fa-9b9a-caa42061993c"
+          },
+          "text": "anchors",
+          "type": "text"
+        }
+      ],
+      "type": "paragraph"
+    }
+  ],
+  "type": "doc",
+  "version": 1
+}

corpus/round-trip/combinations/carry-text-attributes.md

@@ -0,0 +1,7 @@
+:adf{json="{\"attrs\":{\"localId\":\"01a0a067-68cf-78af-abd6-c660ec0d189b\"},\"text\":\"Owner\",\"type\":\"text\"}"} signs off.
+
+Signed by :adf{json="{\"attrs\":{\"localId\":\"01a0a067-68d2-787e-afc5-2459776aa029\"},\"text\":\"the owner\",\"type\":\"text\"}"}
+
+:adf{json="{\"attrs\":{\"localId\":\"01a0a067-68d5-7372-9962-29a039654056\"},\"text\":\"One \",\"type\":\"text\"}"}:adf{json="{\"attrs\":{\"localId\":\"01a0a067-68d5-7372-9962-29a039654056\"},\"text\":\"anchor\",\"type\":\"text\"}"}
+
+:adf{json="{\"attrs\":{\"localId\":\"01a0a067-68cf-78af-abd6-c660ec0d189b\"},\"text\":\"Two \",\"type\":\"text\"}"}:adf{json="{\"attrs\":{\"localId\":\"01a0a067-68d9-73fa-9b9a-caa42061993c\"},\"text\":\"anchors\",\"type\":\"text\"}"}

spec/flavour.md

@@ -404,10 +404,10 @@ Right.
 Attributes and the carry fallback read as in the block sections, the carry in its inline form. Of
 the nodes below, `emoji`, `mention` and `status` spell their `text` attribute in the content slot
 as plain text: `[]` is the empty string, absent content is the absent attribute, non-empty content
-parsing to anything but one unmarked text node — adjacent identical-mark text nodes merged first —
-is a named error, and so is a `text` key in `{attrs}`. An enclosing mark spelling does not reach
-into the slot. The rest take no content, `:text` included; content on a node that takes none is a
-named error.
+parsing to anything but one unmarked text node — adjacent text nodes with identical marks and no
+attributes merged first — is a named error, and so is a `text` key in `{attrs}`. An enclosing mark
+spelling does not reach into the slot. The rest take no content, `:text` included; content on a
+node that takes none is a named error.
 
 - `date` — Attributes: `localId` (string), `timestamp` (string, epoch milliseconds).
 - `emoji` — Attributes: `id` (string), `localId` (string), `shortName` (string, `:name:`), `text`
@@ -434,10 +434,10 @@ CommonMark strips or refuses one — a block's inline content edges, either side
 an em, strong or strike spelling's inner edges, a pipe cell's edges — is spelled
 `:text{text="…"}`, the reserved key carrying the node's text, escaped by the attribute grammar
 and never literal: pipe cells trim and pad. The emitter wraps the whitespace run alone and leaves
-the rest plain text; `markdownToAdf` merges adjacent text nodes carrying identical marks
-(AGENTS.md §2). Input reads that spelling alone: the value is one run of spaces and tabs, or one
-run of newlines, and anything else — a mixed run, or text CommonMark carries plainly — is a named
-error.
+the rest plain text; `markdownToAdf` merges adjacent text nodes carrying identical marks and no
+attributes (AGENTS.md §2). Input reads that spelling alone: the value is one run of spaces and
+tabs, or one run of newlines, and anything else — a mixed run, or text CommonMark carries plainly —
+is a named error.
 
 ```
 :text{text="  "}Two leading spaces held, and one text node split:text{text="\n"}over two lines.

src/adf/editor-normal.ts

@@ -5,12 +5,12 @@ export function sameMark(candidate: AdfMark, mark: AdfMark): boolean {
   return markKey(candidate) === markKey(mark)
 }
 
-// AGENTS.md §2: adjacent text nodes carrying identical marks are one node.
+// AGENTS.md §2: adjacent text nodes carrying identical marks and no attributes are one node.
 export function mergeAdjacentText(nodes: readonly AdfNode[]): AdfNode[] {
   const merged: AdfNode[] = []
   for (const node of nodes) {
     const previous = merged[merged.length - 1]
-    if (previous !== undefined && previous.type === 'text' && node.type === 'text' && sameMarks(previous, node)) {
+    if (previous !== undefined && mergesText(previous) && mergesText(node) && sameMarks(previous, node)) {
       merged[merged.length - 1] = { ...previous, text: `${previous.text ?? ''}${node.text ?? ''}` }
       continue
     }
@@ -19,6 +19,10 @@ export function mergeAdjacentText(nodes: readonly AdfNode[]): AdfNode[] {
   return merged
 }
 
+function mergesText(node: AdfNode): boolean {
+  return node.type === 'text' && Object.keys(node.attrs ?? {}).length === 0
+}
+
 function sameMarks(previous: AdfNode, node: AdfNode): boolean {
   return marksKey(previous.marks ?? []) === marksKey(node.marks ?? [])
 }