wip(ssr): initial scaffold for compiler-ssr

packages/compiler-ssr/src/codegen.ts

@@ -0,0 +1,94 @@
+import {
+  CodegenResult,
+  RootNode,
+  generate as baseGenerate,
+  CodegenOptions,
+  NodeTypes,
+  locStub,
+  BlockStatement,
+  ElementTypes,
+  createCallExpression,
+  TemplateLiteral,
+  createTemplateLiteral,
+  CallExpression,
+  TemplateChildNode
+} from '@vue/compiler-dom'
+import { isString } from '@vue/shared'
+
+export function generate(
+  ast: RootNode,
+  options: CodegenOptions
+): CodegenResult {
+  // construct a SSR-specific codegen tree to pass to core codegen
+  const body: BlockStatement['body'] = []
+  let currentCall: CallExpression | null = null
+  let currentString: TemplateLiteral | null = null
+
+  function ensureCurrentString() {
+    if (!currentCall) {
+      currentCall = createCallExpression(`_push`)
+      body.push(currentCall)
+    }
+    if (!currentString) {
+      currentString = createTemplateLiteral([])
+      currentCall.arguments.push(currentString)
+    }
+    return currentString.elements
+  }
+
+  function pushStringPart(part: TemplateLiteral['elements'][0]) {
+    const bufferedElements = ensureCurrentString()
+    const lastItem = bufferedElements[bufferedElements.length - 1]
+    if (isString(part) && isString(lastItem)) {
+      bufferedElements[bufferedElements.length - 1] += part
+    } else {
+      bufferedElements.push(part)
+    }
+  }
+
+  function processChildren(children: TemplateChildNode[]) {
+    for (let i = 0; i < children.length; i++) {
+      const child = children[i]
+      if (child.type === NodeTypes.ELEMENT) {
+        if (child.tagType === ElementTypes.ELEMENT) {
+          const elementsToAdd = child.ssrCodegenNode!.elements
+          for (let j = 0; j < elementsToAdd.length; j++) {
+            pushStringPart(elementsToAdd[j])
+          }
+          if (child.children.length) {
+            processChildren(child.children)
+          }
+          // push closing tag
+          pushStringPart(`</${child.tag}>`)
+        } else if (child.tagType === ElementTypes.COMPONENT) {
+          // TODO
+        } else if (child.tagType === ElementTypes.SLOT) {
+          // TODO
+        }
+      } else if (child.type === NodeTypes.TEXT) {
+        // TODO
+      } else if (child.type === NodeTypes.IF) {
+        // TODO
+      } else if (child.type === NodeTypes.FOR) {
+        // TODO
+      }
+    }
+  }
+
+  const isFragment = ast.children.length > 1
+  if (isFragment) {
+    pushStringPart(`<!---->`)
+  }
+  processChildren(ast.children)
+  if (isFragment) {
+    pushStringPart(`<!---->`)
+  }
+
+  ast.codegenNode = {
+    type: NodeTypes.JS_BLOCK_STATEMENT,
+    loc: locStub,
+    body
+  }
+
+  return baseGenerate(ast, options)
+}

packages/compiler-ssr/src/index.ts

@@ -1,3 +1,63 @@
-export function hello(): string {
-  return 'TODO'
+import {
+  CodegenResult,
+  baseParse,
+  parserOptions,
+  transform,
+  generate,
+  CompilerOptions,
+  transformExpression,
+  trackVForSlotScopes,
+  trackSlotScopes
+} from '@vue/compiler-dom'
+import { ssrCodegenTransform } from './ssrCodegenTransform'
+import { ssrTransformIf } from './transforms/ssrVIf'
+import { ssrTransformFor } from './transforms/ssrVFor'
+import { ssrTransformElement } from './transforms/ssrTransformElement'
+import { ssrTransformComponent } from './transforms/ssrTransformComponent'
+import { ssrTransformSlotOutlet } from './transforms/ssrTransformSlotOutlet'
+
+export interface SSRCompilerOptions extends CompilerOptions {}
+
+export function compile(
+  template: string,
+  options: SSRCompilerOptions = {}
+): CodegenResult {
+  const ast = baseParse(template, {
+    ...parserOptions,
+    ...options
+  })
+
+  transform(ast, {
+    ...options,
+    prefixIdentifiers: true,
+    // disalbe optimizations that are unnecessary for ssr
+    cacheHandlers: false,
+    hoistStatic: false,
+    nodeTransforms: [
+      ssrTransformIf,
+      ssrTransformFor,
+      trackVForSlotScopes,
+      transformExpression,
+      ssrTransformSlotOutlet,
+      ssrTransformElement,
+      ssrTransformComponent,
+      trackSlotScopes,
+      ...(options.nodeTransforms || []) // user transforms
+    ],
+    directiveTransforms: {
+      // TODO server-side directive transforms
+      ...(options.directiveTransforms || {}) // user transforms
+    }
+  })
+
+  // traverse the template AST and convert into SSR codegen AST
+  // by replacing ast.codegenNode.
+  ssrCodegenTransform(ast)
+
+  return generate(ast, {
+    mode: 'cjs',
+    ...options,
+    ssr: true,
+    prefixIdentifiers: true
+  })
 }

packages/compiler-ssr/src/runtimeHelpers.ts

@@ -0,0 +1 @@
+//

packages/compiler-ssr/src/ssrCodegenTransform.ts

@@ -0,0 +1,99 @@
+import {
+  RootNode,
+  BlockStatement,
+  CallExpression,
+  TemplateLiteral,
+  createCallExpression,
+  createTemplateLiteral,
+  locStub,
+  NodeTypes,
+  TemplateChildNode,
+  ElementTypes
+} from '@vue/compiler-dom'
+import { isString } from '@vue/shared'
+
+// Because SSR codegen output is completely different from client-side output
+// (e.g. multiple elements can be concatenated into a single template literal
+// instead of each getting a corresponding call), we need to apply an extra
+// transform pass to convert the template AST into a fresh JS AST before
+// passing it to codegen.
+
+export function ssrCodegenTransform(ast: RootNode) {
+  const context = createSSRTransformContext()
+
+  const isFragment = ast.children.length > 1
+  if (isFragment) {
+    context.pushStringPart(`<!---->`)
+  }
+  processChildren(ast.children, context)
+  if (isFragment) {
+    context.pushStringPart(`<!---->`)
+  }
+
+  ast.codegenNode = {
+    type: NodeTypes.JS_BLOCK_STATEMENT,
+    loc: locStub,
+    body: context.body
+  }
+}
+
+type SSRTransformContext = ReturnType<typeof createSSRTransformContext>
+
+function createSSRTransformContext() {
+  const body: BlockStatement['body'] = []
+  let currentCall: CallExpression | null = null
+  let currentString: TemplateLiteral | null = null
+
+  return {
+    body,
+    pushStringPart(part: TemplateLiteral['elements'][0]) {
+      if (!currentCall) {
+        currentCall = createCallExpression(`_push`)
+        body.push(currentCall)
+      }
+      if (!currentString) {
+        currentString = createTemplateLiteral([])
+        currentCall.arguments.push(currentString)
+      }
+      const bufferedElements = currentString.elements
+      const lastItem = bufferedElements[bufferedElements.length - 1]
+      if (isString(part) && isString(lastItem)) {
+        bufferedElements[bufferedElements.length - 1] += part
+      } else {
+        bufferedElements.push(part)
+      }
+    }
+  }
+}
+
+function processChildren(
+  children: TemplateChildNode[],
+  context: SSRTransformContext
+) {
+  for (let i = 0; i < children.length; i++) {
+    const child = children[i]
+    if (child.type === NodeTypes.ELEMENT) {
+      if (child.tagType === ElementTypes.ELEMENT) {
+        const elementsToAdd = child.ssrCodegenNode!.elements
+        for (let j = 0; j < elementsToAdd.length; j++) {
+          context.pushStringPart(elementsToAdd[j])
+        }
+        if (child.children.length) {
+          processChildren(child.children, context)
+        }
+        // push closing tag
+        context.pushStringPart(`</${child.tag}>`)
+      } else if (child.tagType === ElementTypes.COMPONENT) {
+        // TODO
+      } else if (child.tagType === ElementTypes.SLOT) {
+        // TODO
+      }
+    } else if (child.type === NodeTypes.TEXT) {
+      // TODO
+    } else if (child.type === NodeTypes.IF) {
+      // TODO
+    } else if (child.type === NodeTypes.FOR) {
+      // TODO
+    }
+  }
+}

packages/compiler-ssr/src/transforms/ssrTransformComponent.ts

@@ -0,0 +1,15 @@
+import { NodeTransform, NodeTypes, ElementTypes } from '@vue/compiler-dom'
+
+export const ssrTransformComponent: NodeTransform = (node, context) => {
+  if (
+    node.type === NodeTypes.ELEMENT &&
+    node.tagType === ElementTypes.COMPONENT
+  ) {
+    return function ssrPostTransformComponent() {
+      // generate a _push(_renderComponent) call
+      // dynamic component as well
+      // !check if we need to bail out for slots
+      // TODO also handle scopeID here
+    }
+  }
+}

packages/compiler-ssr/src/transforms/ssrTransformElement.ts

@@ -0,0 +1,70 @@
+import {
+  NodeTransform,
+  NodeTypes,
+  ElementTypes,
+  TemplateLiteral,
+  createTemplateLiteral
+} from '@vue/compiler-dom'
+import { escapeHtml } from '@vue/server-renderer/src'
+
+/*
+## Simple Element
+
+``` html
+<div></div>
+```
+``` js
+return function render(_ctx, _push, _parent) {
+  _push(`<div></div>`)
+}
+```
+
+## Consecutive Elements
+
+``` html
+<div>
+  <span></span>
+</div>
+<div></div>
+```
+``` js
+return function render(_ctx, _push, _parent) {
+  _push(`<div><span></span></div><div></div>`)
+}
+```
+*/
+
+export const ssrTransformElement: NodeTransform = (node, context) => {
+  if (
+    node.type === NodeTypes.ELEMENT &&
+    node.tagType === ElementTypes.ELEMENT
+  ) {
+    return function ssrPostTransformElement() {
+      // element
+      // generate the template literal representing the open tag.
+      const openTag: TemplateLiteral['elements'] = [`<${node.tag}`]
+
+      for (let i = 0; i < node.props.length; i++) {
+        const prop = node.props[i]
+        if (prop.type === NodeTypes.DIRECTIVE) {
+          const directiveTransform = context.directiveTransforms[prop.name]
+          if (directiveTransform) {
+            // TODO directive transforms
+          } else {
+            // no corresponding ssr directive transform found.
+            // TODO emit error
+          }
+        } else {
+          // static prop
+          openTag.push(
+            ` ${prop.name}` +
+              (prop.value ? `="${escapeHtml(prop.value.content)}"` : ``)
+          )
+        }
+      }
+
+      openTag.push(`>`)
+      node.ssrCodegenNode = createTemplateLiteral(openTag)
+    }
+  }
+}

packages/compiler-ssr/src/transforms/ssrTransformSlotOutlet.ts

@@ -0,0 +1,3 @@
+import { NodeTransform } from '@vue/compiler-dom'
+
+export const ssrTransformSlotOutlet: NodeTransform = () => {}

packages/compiler-ssr/src/transforms/ssrVBind.ts

@@ -0,0 +1 @@
+// TODO

packages/compiler-ssr/src/transforms/ssrVCloak.ts

@@ -0,0 +1 @@
+// TODO

packages/compiler-ssr/src/transforms/ssrVFor.ts

@@ -0,0 +1,3 @@
+import { NodeTransform } from '@vue/compiler-dom'
+
+export const ssrTransformFor: NodeTransform = () => {}

packages/compiler-ssr/src/transforms/ssrVHtml.ts

@@ -0,0 +1 @@
+// TODO

packages/compiler-ssr/src/transforms/ssrVIf.ts

@@ -0,0 +1,3 @@
+import { NodeTransform } from '@vue/compiler-dom'
+
+export const ssrTransformIf: NodeTransform = () => {}

packages/compiler-ssr/src/transforms/ssrVModel.ts

@@ -0,0 +1 @@
+// TODO

packages/compiler-ssr/src/transforms/ssrVOn.ts

@@ -0,0 +1 @@
+// TODO

packages/compiler-ssr/src/transforms/ssrVShow.ts

@@ -0,0 +1 @@
+// TODO

packages/compiler-ssr/src/transforms/ssrVSlot.ts

@@ -0,0 +1 @@
+// TODO

packages/compiler-ssr/src/transforms/ssrVText.ts

@@ -0,0 +1 @@
+// TODO