2

我正在尝试改变它：

function twist() {
  this.settings = null;
  delete this.settings;
  this.whatever = null;
  this.something['hello'] = null;
  this.hello = "test";
}

进入这个：

function twist() {
  delete this.settings;
  delete this.settings;
  delete this.whatever;
  delete this.something['hello'];
  this.hello = "test";
}

所以我为jscodeshift编写了以下codemod：

export default function transformer(file, api) {
  const j = api.jscodeshift;

  return j(file.source)
    .find(j.ExpressionStatement, {expression: j.BinaryExpression})
    .filter(p => p.value.expression.operator === "=")
    .filter(p => p.value.expression.right.type === "Literal" && p.value.expression.right.raw === "null")
    .filter(p => p.value.expression.left.type === "MemberExpression")
    .replaceWith(path => j.unaryExpression("delete", path.value.expression.left))
    //.filter(p => { console.log(p.value); return true;})
    .toSource();
}

但我得到了错误：

{operator: delete, argument: [object Object], prefix: true, loc: null, type: UnaryExpression, comments: null} does not match type string
4

1 回答 1

2

您的代码正在做的是将 替换ExpressionStatement为UnaryExpression. 替换Statements为Expressions可能很挑剔。

它还查找 a BinaryExpression，但 BinaryExpression 没有=作为运算符。

您的过滤器实际上应该是 a AssignmentExpression，因为您真正想要做的是用 a替换AssignmentExpression内部，从而用另一个替换一个。ExpressionStatementUnaryExpressionExpression

export default function transformer(file, api) {
  const j = api.jscodeshift;

  return j(file.source)
    .find(j.AssignmentExpression, {
      operator: "=",
      right: {
        type: "Literal",
        value: null
      }
    })
    .replaceWith(({ node: { left } }) => j.unaryExpression("delete", left))
    .toSource();
}

这是一个 ASTExplorer 示例：https ://astexplorer.net/#/gist/afb441a9709f82cd6fc3ba2860c98823/6f21cdb12a5a43aa1ca460aaa40d9ef63e1ef4bc

于 2019-06-29T12:42:47.403 回答