From c4fc82595d1a5f23ec56a1ca1f90a541d69ea50f Mon Sep 17 00:00:00 2001
From: Rahul Kadyan <hi@znck.me>
Date: Tue, 3 Oct 2017 08:19:11 +0530
Subject: [PATCH] feat: template to render function compiler

---
 src/template-compiler/index.js                | 68 +++++++++++++++++++
 .../modules/transform-require.js              | 48 +++++++++++++
 test/template-compiler.test.js                | 32 +++++++++
 3 files changed, 148 insertions(+)
 create mode 100644 src/template-compiler/index.js
 create mode 100644 src/template-compiler/modules/transform-require.js
 create mode 100644 test/template-compiler.test.js

diff --git a/src/template-compiler/index.js b/src/template-compiler/index.js
new file mode 100644
index 0000000..a796e05
--- /dev/null
+++ b/src/template-compiler/index.js
@@ -0,0 +1,68 @@
+const compiler = require('vue-template-compiler')
+const transpile = require('vue-template-es2015-compiler')
+const { js_beautify: beautify } = require('js-beautify')
+
+const transformRequire = require('./modules/transform-require')
+
+module.exports = function compileTemplate (template, filename, config) {
+  const options = Object.assign({
+    preserveWhitespace: true
+  }, config.options, {
+    modules: [transformRequire(config.transformToRequire)].concat(config.plugins || [])
+  })
+  const compile = (config.isServer && config.optimizeSSR !== false && compiler.ssrCompile) ? compiler.ssrCompile : compiler.compile
+  const compiled = compile(template.code, options)
+  const output = {
+    errors: compiled.errors,
+    tips: compiled.tips
+  }
+
+  if (output.errors && output.errors.length) {
+    output.code = config.esModule !== false
+      ? `export function render () {}\nexport var staticRenderFns = []`
+      : 'module.exports={render:function(){},staticRenderFns:[]}'
+  } else {
+    output.code = transpile(
+      'var render = ' + toFunction(compiled.render) + '\n' +
+      'var staticRenderFns = [' + compiled.staticRenderFns.map(toFunction).join(',') + ']',
+      config.buble
+    ) + '\n'
+
+    // mark with stripped (this enables Vue to use correct runtime proxy detection)
+    if (
+      !config.isProduction && (
+      !config.buble ||
+      !config.buble.transforms ||
+      config.buble.transforms.stripWith !== false
+    )) {
+      output.code += `render._withStripped = true\n`
+    }
+
+    const __exports__ = `{ render: render, staticRenderFns: staticRenderFns }`
+    output.code += config.esModule !== false
+      ? `export default ${__exports__}`
+      : `module.exports = ${__exports__}`
+
+    if (!config.isProduction && config.isHot) {
+      output.code +=
+        '\nif (module.hot) {\n' +
+        '  module.hot.accept()\n' +
+        '  if (module.hot.data) {\n' +
+        `     require('vue-hot-reload-api').rerender('${options.scopeId}', module.exports)\n` +
+        '  }\n' +
+        '}'
+    }
+  }
+
+  return Promise.resolve(output)
+}
+
+function toFunction (code) {
+  return 'function () {' + beautify(code, {
+    indent_size: 2 // eslint-disable-line camelcase
+  }) + '}'
+}
+
+function pad (html) {
+  return html.split(/\r?\n/).map(line => `  ${line}`).join('\n')
+}
diff --git a/src/template-compiler/modules/transform-require.js b/src/template-compiler/modules/transform-require.js
new file mode 100644
index 0000000..edf7f47
--- /dev/null
+++ b/src/template-compiler/modules/transform-require.js
@@ -0,0 +1,48 @@
+// vue compiler module for transforming `<tag>:<attribute>` to `require`
+const defaultOptions = {
+  img: 'src',
+  image: 'xlink:href'
+}
+
+module.exports = userOptions => {
+  const options = userOptions
+    ? Object.assign({}, defaultOptions, userOptions)
+    : defaultOptions
+
+  return {
+    postTransformNode: node => {
+      transform(node, options)
+    }
+  }
+}
+
+function transform (node, options) {
+  for (const tag in options) {
+    if (node.tag === tag && node.attrs) {
+      const attributes = options[tag]
+      if (typeof attributes === 'string') {
+        node.attrs.some(attr => rewrite(attr, attributes))
+      } else if (Array.isArray(attributes)) {
+        attributes.forEach(item => node.attrs.some(attr => rewrite(attr, item)))
+      }
+    }
+  }
+}
+
+function rewrite (attr, name) {
+  if (attr.name === name) {
+    let value = attr.value
+    const isStatic = value.charAt(0) === '"' && value.charAt(value.length - 1) === '"'
+    if (!isStatic) {
+      return
+    }
+    const firstChar = value.charAt(1)
+    if (firstChar === '.' || firstChar === '~') {
+      if (firstChar === '~') {
+        value = '"' + value.slice(2)
+      }
+      attr.value = `require(${value})`
+    }
+    return true
+  }
+}
diff --git a/test/template-compiler.test.js b/test/template-compiler.test.js
new file mode 100644
index 0000000..9b905ca
--- /dev/null
+++ b/test/template-compiler.test.js
@@ -0,0 +1,32 @@
+const compiler = require('../src/template-compiler')
+
+test('should compile template to esModule', async () => {
+  const template = {
+    code: '<div>{{foo}}</div>\n'
+  }
+  const compiled = await compiler(template, 'foo.vue', { scopeId: 'xxx' })
+
+  expect(compiled.code.indexOf('export default')).toBeGreaterThan(-1)
+  expect(compiled.code.indexOf('render._withStripped')).toBeGreaterThan(-1)
+  expect(compiled.code.indexOf('module.hot.accept')).toBe(-1)
+})
+
+test('should compile template to node module', async () => {
+  const template = {
+    code: '<div>{{foo}}</div>\n'
+  }
+  const compiled = await compiler(template, 'foo.vue', { scopeId: 'xxx', esModule: false })
+
+  expect(compiled.code.indexOf('export default')).toBe(-1)
+  expect(compiled.code.indexOf('render._withStripped')).toBeGreaterThan(-1)
+  expect(compiled.code.indexOf('module.hot.accept')).toBe(-1)
+})
+
+test('should compile with HMR', async () => {
+  const template = {
+    code: '<div>{{foo}}</div>\n'
+  }
+  const compiled = await compiler(template, 'foo.vue', { scopeId: 'xxx', isHot: true })
+
+  expect(compiled.code.indexOf('module.hot.accept')).toBeGreaterThan(-1)
+})