Group the semantic diff comment's changelog entries as the changelog does

scripts/commitRecords.js

@@ -65,15 +65,13 @@ function changelog(base, tip) {
           name,
           git(["show", `${tip}:${f}`]),
         );
-        const emoji =
-          /:\w+:/.exec(
-            categories[/** @type {keyof typeof categories} */ (category)],
-          )?.[0] ?? "";
-        return { category, emoji, text };
+        const heading =
+          categories[/** @type {keyof typeof categories} */ (category)];
+        return { category, heading, text };
       } catch {
         return {
           category: "",
-          emoji: ":grey_question:",
+          heading: "#### :grey_question: Not a changelog fragment",
           text: `- \`${name}\``,
         };
       }

scripts/commitRecords.test.js

@@ -933,7 +933,7 @@ test("the comment lists the changelog entries a range adds, breaking first", asy
   const comment = await fs.readFile(md, "utf8");
   has(
     comment,
-    "### Changelog\n\n- :boom: Drop -x.\n- :bug: Recover the watcher.\n- :grey_question: `Bad Name.md`\n\n",
+    "### Changelog\n\n#### :boom: Breaking Change\n\n- Drop -x.\n\n#### :bug: Bug fix\n\n- Recover the watcher.\n\n#### :grey_question: Not a changelog fragment\n\n- `Bad Name.md`\n\n",
   );
   lacks(comment, "Old.");
   lacks(comment, "Tmp.");

scripts/recordMarkdown.js

@@ -38,8 +38,9 @@ import {
 
 /**
  * A changelog fragment the pull request adds: its category, the category's
- * emoji as the changelog heads it (`:boom:`), and its Markdown bullets.
- * @typedef {{ category: string, emoji: string, text: string }} ChangelogEntry
+ * heading as the changelog has it (`#### :boom: Breaking Change`), and its
+ * Markdown bullets.
+ * @typedef {{ category: string, heading: string, text: string }} ChangelogEntry
  */
 
 /** The characters a comment holds at most, with room for the action's tag. */
@@ -442,27 +443,31 @@ export function commitMarkdown(r, full, change = "") {
 }
 
 /**
- * The changelog entries as a list, each bullet led by its entry's emoji, in
- * at most `room` characters: the comment shortens commits to fit its
- * budget but not the changelog, so entries past the room are counted, not
- * drawn.
+ * The changelog entries grouped under their categories' headings, as the
+ * changelog groups them (the entries come in its order), in at most `room`
+ * characters: the comment shortens commits to fit its budget but not the
+ * changelog, so entries past the room are counted, not drawn.
  * @param {ChangelogEntry[]} changelog
  * @param {number} room
  */
 function changelogList(changelog, room) {
   if (!changelog.length) return "No changelog entry.";
   const drawn = [];
   let size = 0;
+  let heading = "";
+  let count = 0;
   for (const e of changelog) {
-    const lines = unmentioned(e.text).replace(/^- /gm, `- ${e.emoji} `);
-    size += lines.length + 1;
+    const lines = `${e.heading === heading ? "" : `${e.heading}\n\n`}${unmentioned(e.text)}`;
+    size += lines.length + 2;
     if (size > room) break;
-    drawn.push(lines);
+    drawn.push(e.heading === heading || !count ? lines : `\n${lines}`);
+    heading = e.heading;
+    count++;
   }
-  const left = changelog.length - drawn.length;
+  const left = changelog.length - count;
   if (left)
     drawn.push(
-      `\n<sub>${left}${drawn.length ? " more" : ""} changelog entr${left === 1 ? "y" : "ies"} under \`changes/\`.</sub>`,
+      `\n<sub>${left}${count ? " more" : ""} changelog entr${left === 1 ? "y" : "ies"} under \`changes/\`.</sub>`,
     );
   return drawn.join("\n");
 }
@@ -474,8 +479,8 @@ function changelogList(changelog, room) {
  * last commits are left to the page. The commits the last push added or
  * edited (`changes`) are marked.
  *
- * The changelog entries the pull request adds (`changelog`, each fragment's
- * bullets led by its category's emoji) describe it as a whole, as its squash
+ * The changelog entries the pull request adds (`changelog`, grouped under
+ * the changelog's category headings) describe it as a whole, as its squash
  * commit will; a commit's `Breaking:` sections describe that commit. They
  * come first, under their own heading, which also notes a pull request
  * whose commits break something while no entry is a breaking change, or

scripts/recordMarkdown.test.js

@@ -270,13 +270,13 @@ test("the heading lists the changelog entries and notes a breaking mismatch", ()
   const plain = `Fix a typo\n\n${SIGNED}\n`;
   const fix = {
     category: "fix",
-    emoji: ":bug:",
+    heading: "#### :bug: Bug fix",
     text: "- Recover @someone's `@raw` build.\n- Keep **watching**,\n  after errors.",
   };
   const md = comment([plain], { changelog: [fix] });
   has(
     md,
-    "### Changelog\n\n- :bug: Recover `@someone`'s `@raw` build.\n- :bug: Keep **watching**,\n  after errors.\n\n### Semantic Diff\n\n1 commit\n\n<details",
+    "### Changelog\n\n#### :bug: Bug fix\n\n- Recover `@someone`'s `@raw` build.\n- Keep **watching**,\n  after errors.\n\n### Semantic Diff\n\n1 commit\n\n<details",
   );
   has(
     comment([plain], { changelog: [] }),
@@ -287,7 +287,17 @@ test("the heading lists the changelog entries and notes a breaking mismatch", ()
     comment([breaking], { changelog: [fix] }),
     "<sub>:boom: A commit says what it breaks (`Breaking:`), but no changelog entry is a breaking change.</sub>\n\n### Semantic Diff",
   );
-  const boom = { category: "breaking", emoji: ":boom:", text: "- -x is gone." };
+  const boom = {
+    category: "breaking",
+    heading: "#### :boom: Breaking Change",
+    text: "- -x is gone.",
+  };
+  has(
+    comment([breaking], {
+      changelog: [boom, fix, { ...fix, text: "- More." }],
+    }),
+    "### Changelog\n\n#### :boom: Breaking Change\n\n- -x is gone.\n\n#### :bug: Bug fix\n\n- Recover `@someone`'s `@raw` build.\n- Keep **watching**,\n  after errors.\n- More.\n\n### Semantic Diff",
+  );
   const both = comment([breaking], { changelog: [boom] });
   assert.ok(!both.includes("<sub>:boom:"));
   has(
@@ -299,15 +309,15 @@ test("the heading lists the changelog entries and notes a breaking mismatch", ()
 test("past a quarter of the budget, changelog entries are counted, not drawn", () => {
   const entry = (/** @type {number} */ k) => ({
     category: "fix",
-    emoji: ":bug:",
+    heading: "#### :bug: Bug fix",
     text: `- Fix ${k}: ${"x".repeat(300)}`,
   });
   const md = comment([`Fix\n\n${SIGNED}\n`], {
     budget: 4000,
     changelog: Array.from({ length: 20 }, (_, k) => entry(k)),
   });
   assert.ok(md.length <= 4000, `${md.length}`);
-  has(md, "- :bug: Fix 0:");
+  has(md, "#### :bug: Bug fix\n\n- Fix 0:");
   assert.ok(!md.includes("Fix 3:"));
   has(
     md,
@@ -316,7 +326,11 @@ test("past a quarter of the budget, changelog entries are counted, not drawn", (
   const huge = comment([`Fix\n\n${SIGNED}\n`], {
     budget: 4000,
     changelog: [
-      { category: "fix", emoji: ":bug:", text: `- ${"y".repeat(5000)}` },
+      {
+        category: "fix",
+        heading: "#### :bug: Bug fix",
+        text: `- ${"y".repeat(5000)}`,
+      },
     ],
   });
   assert.ok(huge.length <= 4000, `${huge.length}`);