fix(core/examples): don't add number to id when possible (speced#3799)

src/core/examples.js

@@ -90,13 +90,7 @@ export function run() {
       ++number;
       const div = makeTitle(example, number, report);
       example.prepend(div);
-      if (title) {
-        addId(example, `example-${number}`, title); // title gets used
-      } else {
-        // use the number as the title... so, e.g., "example-5"
-        addId(example, "example", String(number));
-      }
-      const { id } = example;
+      const id = addId(example, "example", title || String(number));
       const selfLink = div.querySelector("a.self-link");
       selfLink.href = `#${id}`;
       pub("example", report);
@@ -115,10 +109,7 @@ export function run() {
       const div = html`<div class="example" id="${id}">
         ${exampleTitle} ${example.cloneNode(true)}
       </div>`;
-      if (title) {
-        addId(div, `example-${number}`, title);
-      }
-      addId(div, `example`, String(number));
+      addId(div, "example", title || String(number));
       const selfLink = div.querySelector("a.self-link");
       selfLink.href = `#${div.id}`;
       example.replaceWith(div);

tests/spec/core/examples-spec.js

@@ -20,7 +20,7 @@ describe("Core — Examples", () => {
     const example = doc.querySelector("div.example pre");
     const div = example.closest("div");
     expect(div.classList).toContain("example");
-    expect(div.id).toBe("example-1-ex");
+    expect(div.id).toBe("example-ex");
 
     const markers = div.querySelectorAll("div.marker");
     expect(markers).toHaveSize(1);
@@ -41,7 +41,7 @@ describe("Core — Examples", () => {
     const ops = makeStandardOps(null, body);
     const doc = await makeRSDoc(ops);
     const example = doc.querySelector("aside.example");
-    expect(example.id).toBe("example-1-ex");
+    expect(example.id).toBe("example-ex");
 
     const markers = example.querySelectorAll("div.marker");
     expect(markers).toHaveSize(1);
@@ -98,7 +98,7 @@ describe("Core — Examples", () => {
     const [example1, example2, example3] = exampleLinks;
     expect(example1.getAttribute("href")).toBe("#example-1");
     expect(example2.getAttribute("href")).toBe("#pass");
-    expect(example3.getAttribute("href")).toBe("#example-3-pass");
+    expect(example3.getAttribute("href")).toBe("#example-pass");
   });
   it("self-links examples made from pre", async () => {
     const body = `
@@ -113,7 +113,7 @@ describe("Core — Examples", () => {
     const [example1, example2, example3] = exampleLinks;
     expect(example1.getAttribute("href")).toBe("#example-1");
     expect(example2.getAttribute("href")).toBe("#pass");
-    expect(example3.getAttribute("href")).toBe("#example-3-pass");
+    expect(example3.getAttribute("href")).toBe("#example-pass");
   });
   it("relocates ids and doesn't duplicate them", async () => {
     const body = `