refactor(fragments): remove visible anchors for fragments

packages/server-renderer/__tests__/renderToString.spec.ts

@@ -262,7 +262,7 @@ describe('ssr: renderToString', () => {
         )
       ).toBe(
         `<div>parent<div class="child">` +
-          `<!----><span>from slot</span><!---->` +
+          `<span>from slot</span>` +
           `</div></div>`
       )
 
@@ -277,7 +277,7 @@ describe('ssr: renderToString', () => {
             }
           })
         )
-      ).toBe(`<div>parent<div class="child"><!---->fallback<!----></div></div>`)
+      ).toBe(`<div>parent<div class="child">fallback</div></div>`)
     })
 
     test('nested components with vnode slots', async () => {
@@ -321,7 +321,7 @@ describe('ssr: renderToString', () => {
         )
       ).toBe(
         `<div>parent<div class="child">` +
-          `<!----><span>from slot</span><!---->` +
+          `<span>from slot</span>` +
           `</div></div>`
       )
     })
@@ -339,7 +339,7 @@ describe('ssr: renderToString', () => {
 
       expect(await renderToString(app)).toBe(
         `<div>parent<div class="child">` +
-          `<!----><span>from slot</span><!---->` +
+          `<span>from slot</span>` +
           `</div></div>`
       )
     })
@@ -461,9 +461,7 @@ describe('ssr: renderToString', () => {
             createCommentVNode('qux')
           ])
         )
-      ).toBe(
-        `<div>foo<span>bar</span><!----><span>baz</span><!----><!--qux--></div>`
-      )
+      ).toBe(`<div>foo<span>bar</span><span>baz</span><!--qux--></div>`)
     })
 
     test('void elements', async () => {

packages/server-renderer/src/helpers/ssrRenderSlot.ts

@@ -19,8 +19,6 @@ export function ssrRenderSlot(
   parentComponent: ComponentInternalInstance
 ) {
   const slotFn = slots[slotName]
-  // template-compiled slots are always rendered as fragments
-  push(`<!---->`)
   if (slotFn) {
     if (slotFn.length > 1) {
       // only ssr-optimized slot fns accept more than 1 arguments
@@ -33,5 +31,4 @@ export function ssrRenderSlot(
   } else if (fallbackRenderFn) {
     fallbackRenderFn()
   }
-  push(`<!---->`)
 }

packages/server-renderer/src/renderToString.ts

@@ -238,9 +238,7 @@ function renderVNode(
       push(children ? `<!--${children}-->` : `<!---->`)
       break
     case Fragment:
-      push(`<!---->`)
       renderVNodeChildren(push, children as VNodeArrayChildren, parentComponent)
-      push(`<!---->`)
       break
     default:
       if (shapeFlag & ShapeFlags.ELEMENT) {