feat(template/pug): add a space based template engine pug support

template-engines/pug/parser.js

@@ -0,0 +1,40 @@
+const tuples = [
+  [/^(\w+)/, 'tag'],
+  [/^\n( *)/, 'indent'],
+  [/\s?([^\n]+)/, 'text'],
+]
+
+module.exports = class Parser {
+  constructor(str) {
+    this.source = str
+    this.capture = []
+    this.ast = []
+    this.currentLine = 0
+    while (this.nextToken) {
+      if (!this.source.length) break
+    }
+  }
+
+  /* eslint no-cond-assign: 0 */
+  get nextToken() {
+    return tuples.some(([reg, type]) => {
+      if (this.capture = reg.exec(this.source)) {
+        if (type === 'indent') {
+          this.currentLine += 1
+        }
+        const token = this.generateToken(type)
+        return this.ast.push(token)
+      }
+      return false
+    })
+  }
+
+  generateToken(type) {
+    this.source = this.source.substr(this.capture[0].length)
+    return {
+      type,
+      val: this.capture[1],
+      line: this.currentLine,
+    }
+  }
+}

template-engines/pug/test/index.js

@@ -0,0 +1,30 @@
+const { readFileSync } = require('fs')
+const { resolve } = require('path')
+const Parser = require('../parser')
+
+test('parser template into AST', () => {
+  const template = readFileSync(resolve(__dirname, 'index.tpug'), 'utf-8')
+  const { ast } = new Parser(template)
+  const expectedAst = [
+    { type: 'tag', line: 0, val: 'html' },
+    { type: 'indent', line: 1, val: '  ' },
+    { type: 'tag', line: 1, val: 'head' },
+    { type: 'indent', line: 2, val: '    ' },
+    { type: 'tag', line: 2, val: 'title' },
+    { type: 'text', line: 2, val: 'tPug' },
+    { type: 'indent', line: 3, val: '  ' },
+    { type: 'tag', line: 3, val: 'body' },
+    { type: 'indent', line: 4, val: '    ' },
+    { type: 'tag', line: 4, val: 'h1' },
+    { type: 'text', line: 4, val: 'Hello World!' },
+    { type: 'indent', line: 5, val: '    ' },
+    { type: 'tag', line: 5, val: 'ul' },
+    { type: 'indent', line: 6, val: '      ' },
+    { type: 'tag', line: 6, val: 'li' },
+    { type: 'text', line: 6, val: 'zhang.zhao' },
+    { type: 'indent', line: 7, val: '      ' },
+    { type: 'tag', line: 7, val: 'li' },
+    { type: 'text', line: 7, val: 'lingli.chen' },
+  ]
+  expect(ast).toEqual(expectedAst)
+})

template-engines/pug/test/index.tpug

@@ -0,0 +1,8 @@
+html
+  head
+    title tPug
+  body
+    h1 Hello World!
+    ul
+      li zhang.zhao
+      li lingli.chen