fix(src/server/render.js): Fixes component directives rendering

Component directives are not being render during SSR, this fixes it by passing the directives data
to its first imediate child.

fix vuejs#10733

src/server/render.js

@@ -201,6 +201,11 @@ function renderComponentInner (node, isRoot, context) {
       type: 'Component',
       prevActive
     })
+    if (isDef(node.data) && isDef(node.data.directives)) {
+      childNode.data = (childNode.data || {})
+      childNode.data.directives = node.data.directives
+      childNode.isComponentRootElement = true
+    }
     renderNode(childNode, isRoot, context)
   }
 
@@ -364,7 +369,7 @@ function renderStartingTag (node: VNode, context) {
           if (dirRenderer) {
             // directives mutate the node's data
             // which then gets rendered by modules
-            dirRenderer(node, dirs[i])
+            dirRenderer(node.isComponentRootElement ? node.parent : node, dirs[i])
           }
         }
       }

test/ssr/ssr-string.spec.js

@@ -829,7 +829,7 @@ describe('SSR: renderToString', () => {
     })
   })
 
-  it('custom directives', done => {
+  it('custom directives on raw element', done => {
     const renderer = createRenderer({
       directives: {
         'class-prefixer': (node, dir) => {
@@ -861,6 +861,80 @@ describe('SSR: renderToString', () => {
     })
   })
 
+  it('custom directives on component', done => {
+    const Test = {
+      template: '<span>hello world</span>'
+    }
+    const renderer = createRenderer({
+      directives: {
+        'class-prefixer': (node, dir) => {
+          if (node.data.class) {
+            node.data.class = `${dir.value}-${node.data.class}`
+          }
+          if (node.data.staticClass) {
+            node.data.staticClass = `${dir.value}-${node.data.staticClass}`
+          }
+        }
+      }
+    })
+    renderer.renderToString(new Vue({
+      template: '<p><Test v-class-prefixer="\'my\'" class="class1" :class="\'class2\'" /></p>',
+      components: { Test },
+    }), (err, result) => {
+      expect(err).toBeNull()
+      expect(result).toContain('<p data-server-rendered="true"><span class="my-class1 my-class2">hello world</span></p>')
+      done()
+    })
+  })
+
+  it('custom directives on element root of a component', done => {
+    const Test = {
+      template: '<span v-class-prefixer="\'my\'" class="class1" :class="\'class2\'">hello world</span>'
+    }
+    const renderer = createRenderer({
+      directives: {
+        'class-prefixer': (node, dir) => {
+          if (node.data.class) {
+            node.data.class = `${dir.value}-${node.data.class}`
+          }
+          if (node.data.staticClass) {
+            node.data.staticClass = `${dir.value}-${node.data.staticClass}`
+          }
+        }
+      }
+    })
+    renderer.renderToString(new Vue({
+      template: '<p><Test /></p>',
+      components: { Test },
+    }), (err, result) => {
+      expect(err).toBeNull()
+      expect(result).toContain('<p data-server-rendered="true"><span class="my-class1 my-class2">hello world</span></p>')
+      done()
+    })
+  })
+
+  it('custom directives on element with parent element', done => {
+    const renderer = createRenderer({
+      directives: {
+        'class-prefixer': (node, dir) => {
+          if (node.data.class) {
+            node.data.class = `${dir.value}-${node.data.class}`
+          }
+          if (node.data.staticClass) {
+            node.data.staticClass = `${dir.value}-${node.data.staticClass}`
+          }
+        }
+      }
+    })
+    renderer.renderToString(new Vue({
+      template: '<p><span v-class-prefixer="\'my\'" class="class1" :class="\'class2\'">hello world</span></p>',
+    }), (err, result) => {
+      expect(err).toBeNull()
+      expect(result).toContain('<p data-server-rendered="true"><span class="my-class1 my-class2">hello world</span></p>')
+      done()
+    })
+  })
+
   it('should not warn for custom directives that do not have server-side implementation', done => {
     renderToString(new Vue({
       directives: {