TypeScript babel-types.expressionStatement函数代码示例

export function evalClass (ast: t.File, props = '', isRequire = false) {
  let mainClass!: t.ClassDeclaration
  const statements = new Set<t.ExpressionStatement>([
    template('Current.inst = this;')() as any
  ])

  traverse(ast, {
    ClassDeclaration (path) {
      mainClass = path.node
    },
    /**
     * 目前 node 的版本支持不了 class-properties
     * 但 babel 又有 bug，某些情况竟然把转换后的 class-properties 编译到 super 之前
     * 不然用 babel.transformFromAst 就完事了
     * 现在只能自己实现这个 feature 的部分功能了，真 tm 麻烦
     * @TODO 有空再给他们提 PR 吧
     */
    ClassProperty (path) {
      const { key, value } = path.node
      statements.add(t.expressionStatement(t.assignmentExpression(
        '=',
        t.memberExpression(
          t.thisExpression(),
          key
        ),
        value
      )))
      path.remove()
    }
  })

  for (const method of mainClass.body.body) {
    // constructor 即便没有被定义也会被加上
    if (t.isClassMethod(method) && method.kind === 'constructor') {
      const index = method.body.body.findIndex(node => t.isSuper(node))
      method.body.body.push(
        t.expressionStatement(t.assignmentExpression(
          '=',
          t.memberExpression(
            t.thisExpression(),
            t.identifier('state')
          ),
          t.callExpression(t.memberExpression(t.thisExpression(), t.identifier('_createData')), [])
        ))
      )
      method.body.body.splice(index, 0, ...statements)
    }
  }

  let code = `function f() {};` +
    generate(t.classDeclaration(t.identifier('Test'), t.identifier('f'), mainClass.body, [])).code +
    ';' + `var classInst =  new Test(${props});classInst`

  code = internalFunction + code

  // tslint:disable-next-line
  return eval(code)
}

 ast.program.body.forEach((node, index, body) => {
   if (node === statementPath.node) {
     body.splice(index + 1, 0, t.expressionStatement(
       t.callExpression(t.identifier('setStore'), [
         t.identifier(storeName)
       ])
     ))
   }
 })

export function parseWXML (dirPath: string, wxml?: string, parseImport?: boolean): {
  wxses: WXS[]
  wxml?: t.Node
  imports: Imports[]
  refIds: Set<string>
} {
  if (!parseImport) {
    errors.length = 0
    usedComponents.clear()
  }
  usedComponents.add('Block')
  let wxses: WXS[] = []
  let imports: Imports[] = []
  const refIds = new Set<string>()
  const loopIds = new Set<string>()
  if (!wxml) {
    return {
      wxses,
      imports,
      refIds,
      wxml: t.nullLiteral()
    }
  }
  const nodes = removEmptyTextAndComment(parse(wxml.trim()))
  const ast = t.file(
    t.program(
      [
        t.expressionStatement(parseNode(
          buildElement('block', nodes as Node[])
        ) as t.Expression)
      ],
      []
    )
  )

  traverse(ast, createWxmlVistor(loopIds, refIds, dirPath, wxses, imports))

  refIds.forEach(id => {
    if (loopIds.has(id) || imports.filter(i => i.wxs).map(i => i.name).includes(id)) {
      refIds.delete(id)
    }
  })

  return {
    wxses,
    imports,
    wxml: hydrate(ast),
    refIds
  }
}

        }
    }
});

// Examples from https://github.com/thejameskyle/babel-handbook/blob/master/translations/en/plugin-handbook.md#writing-your-first-babel-plugin

const v1: Visitor = {
    BinaryExpression(path) {
        if (t.isIdentifier(path.node.left)) {
            // ...
        }
        path.replaceWith(
            t.binaryExpression("**", path.node.left, t.numericLiteral(2))
        );
        path.parentPath.replaceWith(
            t.expressionStatement(t.stringLiteral("Anyway the wind blows, doesn't really matter to me, to me."))
        );
        path.parentPath.remove();
    },

    Identifier(path) {
        if (path.isReferencedIdentifier()) {
            // ...
        }
        if (t.isReferenced(path.node, path.parent)) {
            // ...
        }
    },

    ReturnStatement(path) {
        path.replaceWithMultiple([

export function parseWXML (dirPath: string, wxml?: string, parseImport?: boolean): {
  wxses: WXS[]
  wxml?: t.Node
  imports: Imports[]
} {
  if (!parseImport) {
    errors.length = 0
  }
  usedComponents.clear()
  let wxses: WXS[] = []
  let imports: Imports[] = []
  if (!wxml) {
    return {
      wxses,
      imports,
      wxml: t.nullLiteral()
    }
  }
  const nodes = removEmptyTextAndComment(parse(wxml.trim()))
  const ast = t.file(
    t.program(
      [
        t.expressionStatement(parseNode(
          buildElement('block', nodes as Node[])
        ) as t.Expression)
      ],
      []
    )
  )

  traverse(ast, {
    JSXAttribute (path) {
      const name = path.node.name as t.JSXIdentifier
      const jsx = path.findParent(p => p.isJSXElement()) as NodePath<
        t.JSXElement
      >
      const valueCopy = cloneDeep(path.get('value').node)
      transformIf(name.name, path, jsx, valueCopy)
      transformLoop(name.name, path, jsx, valueCopy)
    },
    JSXElement: {
      enter (path: NodePath<t.JSXElement>) {
        const openingElement = path.get('openingElement')
        const jsxName = openingElement.get('name')
        const attrs = openingElement.get('attributes')
        if (!jsxName.isJSXIdentifier()) {
          return
        }
        const tagName = jsxName.node.name
        if (tagName === 'Wxs') {
          wxses.push(getWXS(attrs.map(a => a.node), path, dirPath))
        }
        if (tagName === 'Template') {
          const template = parseTemplate(path, dirPath)
          if (template) {
            const { ast: classDecl, name } = template
            const taroComponentsImport = buildImportStatement('@tarojs/components', [
              ...usedComponents
            ])
            const taroImport = buildImportStatement('@tarojs/taro', [], 'Taro')
            // const withWeappImport = buildImportStatement(
            //   '@tarojs/with-weapp',
            //   [],
            //   'withWeapp'
            // )
            const ast = t.file(t.program([]))
            ast.program.body.unshift(
              taroComponentsImport,
              taroImport,
              // withWeappImport,
              t.exportDefaultDeclaration(classDecl)
            )
            imports.push({
              ast,
              name
            })
          }
        }
        if (tagName === 'Import') {
          const mods = parseModule(path, dirPath, 'import')
          if (mods) {
            imports = imports.concat(mods)
          }
        }
        if (tagName === 'Include') {
          parseModule(path, dirPath, 'include')
        }
      },
      exit (path: NodePath<t.JSXElement>) {
        const openingElement = path.get('openingElement')
        const jsxName = openingElement.get('name')
        if (!jsxName.isJSXIdentifier({ name: 'Block' })) {
          return
        }
        const children = path.node.children
        if (children.length === 1) {
          const caller = children[0]
          if (t.isJSXExpressionContainer(caller) && t.isCallExpression(caller.expression) && !path.parentPath.isExpressionStatement()) {
            path.replaceWith(caller)
          }
//.........这里部分代码省略.........

//.........这里部分代码省略.........
      if (prop.isObjectMethod()) {
        const body = prop.get('body')
        if (hasArguments) {
          return t.classMethod('method', t.identifier(name), params, body.node)
        }
        return t.classProperty(
          t.identifier(name),
          t.arrowFunctionExpression(params, body.node, isAsync)
        )
      }

      if (hasArguments && (value.isFunctionExpression() || value.isArrowFunctionExpression())) {
        const method = t.classMethod('method', t.identifier(name), params, value.node.body as any)
        method.async = isAsync
        return method
      }

      const classProp = t.classProperty(
        t.identifier(name),
        value.isFunctionExpression() || value.isArrowFunctionExpression()
          ? t.arrowFunctionExpression(value.node.params, value.node.body, isAsync)
          : value.node
      ) as any

      if (staticProps.includes(name)) {
        classProp.static = true
      }

      return classProp
    })

    if (globals.hasCatchTrue) {
      classBody.push(t.classMethod('method', t.identifier('privateStopNoop'), [t.identifier('e')], t.blockStatement([
        t.expressionStatement(
          t.callExpression(
            t.memberExpression(t.identifier('e'), t.identifier('stopPropagation')),
            []
          )
        )
      ])))
    }

    if (defaultProps.length) {
      let classProp = t.classProperty(t.identifier('defaultProps'), t.objectExpression(
        defaultProps.map(p => t.objectProperty(t.identifier(p.name), p.value))
      )) as any
      classProp.static = true
      classBody.unshift(classProp)
    }
  } else if (arg.isIdentifier()) {
    weappConf = arg.node.name
  } else {
    throw codeFrameError(arg.node, `${componentType || '组件'} 的第一个参数必须是一个对象或变量才能转换。`)
  }

  if (json && t.isObjectExpression(json)) {
    classBody.push(t.classProperty(t.identifier('config'), json))
  }

  if (componentType === 'App') {
    let hasWillMount = false
    const globalData = template(`this.$app.globalData = this.globalData`)()
    for (const method of classBody) {
      if (!method) {
        continue
      }

export function generateAnonymousState (
  scope: Scope,
  expression: NodePath<t.Expression>,
  refIds: Set<t.Identifier>,
  isLogical?: boolean
) {
  let variableName = `anonymousState_${scope.generateUid()}`
  let statementParent = expression.getStatementParent()
  if (!statementParent) {
    throw codeFrameError(expression.node.loc, '无法生成匿名 State，尝试先把值赋到一个变量上再把变量调换。')
  }
  const jsx = isLogical ? expression : expression.findParent(p => p.isJSXElement())
  const callExpr = jsx.findParent(p => p.isCallExpression() && isArrayMapCallExpression(p)) as NodePath<t.CallExpression>
  const ifExpr = jsx.findParent(p => p.isIfStatement())
  const blockStatement = jsx.findParent(p => p.isBlockStatement() && p.parentPath === ifExpr) as NodePath<t.BlockStatement>
  const expr = setParentCondition(jsx, cloneDeep(expression.node))
  if (!callExpr) {
    refIds.add(t.identifier(variableName))
    statementParent.insertBefore(
      buildConstVariableDeclaration(variableName, expr)
    )
    if (blockStatement && blockStatement.isBlockStatement()) {
      blockStatement.traverse({
        VariableDeclarator: (path) => {
          const { id, init } = path.node
          const isArrowFunctionInJSX = path.findParent(p => p.isJSXAttribute() ||
            (
              p.isAssignmentExpression() && t.isMemberExpression(p.node.left) && t.isThisExpression(p.node.left.object)
                && t.isIdentifier(p.node.left.property) && p.node.left.property.name.startsWith('')
            )
          )
          if (isArrowFunctionInJSX) {
            return
          }
          if (t.isIdentifier(id) && !id.name.startsWith(LOOP_STATE)) {
            const newId = scope.generateDeclaredUidIdentifier('$' + id.name)
            refIds.forEach((refId) => {
              if (refId.name === variableName && !variableName.startsWith('_$')) {
                refIds.delete(refId)
              }
            })
            variableName = newId.name
            if (Adapter.type === Adapters.quickapp && variableName.startsWith('_$')) {
              const newVarName = variableName.slice(2)
              scope.rename(variableName, newVarName)
              variableName = newVarName
            }
            refIds.add(t.identifier(variableName))
            blockStatement.scope.rename(id.name, newId.name)
            path.parentPath.replaceWith(
              template('ID = INIT;')({ ID: newId, INIT: init })
            )
          }
        }
      })
    }
  } else {
    variableName = `${LOOP_STATE}_${callExpr.scope.generateUid()}`
    const func = callExpr.node.arguments[0]
    if (t.isArrowFunctionExpression(func)) {
      if (!t.isBlockStatement(func.body)) {
        func.body = t.blockStatement([
          buildConstVariableDeclaration(variableName, expr),
          t.returnStatement(func.body)
        ])
      } else {
        if (ifExpr && ifExpr.isIfStatement() && ifExpr.findParent(p => p === callExpr)) {
          const consequent = ifExpr.get('consequent')
          const test = ifExpr.get('test')
          if (consequent.isBlockStatement()) {
            if (jsx === test || jsx.findParent(p => p === test)) {
              func.body.body.unshift(buildConstVariableDeclaration(variableName, expr))
            } else {
              func.body.body.unshift(t.variableDeclaration('let', [t.variableDeclarator(t.identifier(variableName), t.nullLiteral())]))
              consequent.node.body.push(t.expressionStatement(t.assignmentExpression(
                '=',
                t.identifier(variableName),
                expr
              )))
            }
          } else {
            throw codeFrameError(consequent.node, 'if 表达式的结果必须由一个花括号包裹')
          }
        } else {
          func.body.body.splice(func.body.body.length - 1, 0, buildConstVariableDeclaration(variableName, expr))
        }
      }
    }
  }
  const id = t.identifier(variableName)
  expression.replaceWith(id)
  return id
}