replacement.js 7.18 KB
"use strict";

exports.__esModule = true;
exports.replaceWithMultiple = replaceWithMultiple;
exports.replaceWithSourceString = replaceWithSourceString;
exports.replaceWith = replaceWith;
exports.replaceExpressionWithStatements = replaceExpressionWithStatements;
exports.replaceInline = replaceInline;
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function _interopRequireWildcard(obj) { if (obj && obj.__esModule) { return obj; } else { var newObj = {}; if (obj != null) { for (var key in obj) { if (Object.prototype.hasOwnProperty.call(obj, key)) newObj[key] = obj[key]; } } newObj["default"] = obj; return newObj; } }

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function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { "default": obj }; }

var _helpersCodeFrame = require("../../helpers/code-frame");

var _helpersCodeFrame2 = _interopRequireDefault(_helpersCodeFrame);

var _index = require("../index");

var _index2 = _interopRequireDefault(_index);

var _index3 = require("./index");

var _index4 = _interopRequireDefault(_index3);

var _helpersParse = require("../../helpers/parse");

var _helpersParse2 = _interopRequireDefault(_helpersParse);

var _types = require("../../types");

var t = _interopRequireWildcard(_types);

/**
 * [Please add a description.]
 */

var hoistVariablesVisitor = {

  /**
   * [Please add a description.]
   */

  Function: function Function() {
    this.skip();
  },

  /**
   * [Please add a description.]
   */

  VariableDeclaration: function VariableDeclaration(node, parent, scope) {
    if (node.kind !== "var") return;

    var bindings = this.getBindingIdentifiers();
    for (var key in bindings) {
      scope.push({ id: bindings[key] });
    }

    var exprs = [];

    var _arr = node.declarations;
    for (var _i = 0; _i < _arr.length; _i++) {
      var declar = _arr[_i];
      if (declar.init) {
        exprs.push(t.expressionStatement(t.assignmentExpression("=", declar.id, declar.init)));
      }
    }

    return exprs;
  }
};

/**
 * Replace a node with an array of multiple. This method performs the following steps:
 *
 *  - Inherit the comments of first provided node with that of the current node.
 *  - Insert the provided nodes after the current node.
 *  - Remove the current node.
 */

function replaceWithMultiple(nodes) {
  this.resync();

  nodes = this._verifyNodeList(nodes);
  t.inheritLeadingComments(nodes[0], this.node);
  t.inheritTrailingComments(nodes[nodes.length - 1], this.node);
  this.node = this.container[this.key] = null;
  this.insertAfter(nodes);
  if (!this.node) this.dangerouslyRemove();
}

/**
 * Parse a string as an expression and replace the current node with the result.
 *
 * NOTE: This is typically not a good idea to use. Building source strings when
 * transforming ASTs is an antipattern and SHOULD NOT be encouraged. Even if it's
 * easier to use, your transforms will be extremely brittle.
 */

function replaceWithSourceString(replacement) {
  this.resync();

  try {
    replacement = "(" + replacement + ")";
    replacement = _helpersParse2["default"](replacement);
  } catch (err) {
    var loc = err.loc;
    if (loc) {
      err.message += " - make sure this is an expression.";
      err.message += "\n" + _helpersCodeFrame2["default"](replacement, loc.line, loc.column + 1);
    }
    throw err;
  }

  replacement = replacement.program.body[0].expression;
  _index2["default"].removeProperties(replacement);
  return this.replaceWith(replacement);
}

/**
 * Replace the current node with another.
 */

function replaceWith(replacement, whateverAllowed) {
  this.resync();

  if (this.removed) {
    throw new Error("You can't replace this node, we've already removed it");
  }

  if (replacement instanceof _index4["default"]) {
    replacement = replacement.node;
  }

  if (!replacement) {
    throw new Error("You passed `path.replaceWith()` a falsy node, use `path.dangerouslyRemove()` instead");
  }

  if (this.node === replacement) {
    return;
  }

  if (this.isProgram() && !t.isProgram(replacement)) {
    throw new Error("You can only replace a Program root node with another Program node");
  }

  // normalise inserting an entire AST
  if (t.isProgram(replacement) && !this.isProgram()) {
    replacement = replacement.body;
    whateverAllowed = true;
  }

  if (Array.isArray(replacement)) {
    if (whateverAllowed) {
      return this.replaceWithMultiple(replacement);
    } else {
      throw new Error("Don't use `path.replaceWith()` with an array of nodes, use `path.replaceWithMultiple()`");
    }
  }

  if (typeof replacement === "string") {
    // triggers an error
    return this.replaceWithSourceString();
  }

  if (this.isNodeType("Statement") && t.isExpression(replacement)) {
    if (!this.canHaveVariableDeclarationOrExpression() && !this.canSwapBetweenExpressionAndStatement(replacement)) {
      // replacing a statement with an expression so wrap it in an expression statement
      replacement = t.expressionStatement(replacement);
    }
  }

  if (this.isNodeType("Expression") && t.isStatement(replacement)) {
    if (!this.canSwapBetweenExpressionAndStatement(replacement)) {
      // replacing an expression with a statement so let's explode it
      return this.replaceExpressionWithStatements([replacement]);
    }
  }

  var oldNode = this.node;
  if (oldNode) t.inheritsComments(replacement, oldNode);

  // replace the node
  this.node = this.container[this.key] = replacement;
  this.type = replacement.type;

  // potentially create new scope
  this.setScope();
}

/**
 * This method takes an array of statements nodes and then explodes it
 * into expressions. This method retains completion records which is
 * extremely important to retain original semantics.
 */

function replaceExpressionWithStatements(nodes) {
  this.resync();

  var toSequenceExpression = t.toSequenceExpression(nodes, this.scope);

  if (toSequenceExpression) {
    return this.replaceWith(toSequenceExpression);
  } else {
    var container = t.functionExpression(null, [], t.blockStatement(nodes));
    container.shadow = true;

    this.replaceWith(t.callExpression(container, []));
    this.traverse(hoistVariablesVisitor);

    // add implicit returns to all ending expression statements
    var last = this.get("callee").getCompletionRecords();
    var _arr2 = last;
    for (var _i2 = 0; _i2 < _arr2.length; _i2++) {
      var lastNode = _arr2[_i2];
      if (!lastNode.isExpressionStatement()) continue;

      var loop = lastNode.findParent(function (path) {
        return path.isLoop();
      });
      if (loop) {
        var uid = this.get("callee").scope.generateDeclaredUidIdentifier("ret");
        this.get("callee.body").pushContainer("body", t.returnStatement(uid));
        lastNode.get("expression").replaceWith(t.assignmentExpression("=", uid, lastNode.node.expression));
      } else {
        lastNode.replaceWith(t.returnStatement(lastNode.node.expression));
      }
    }

    return this.node;
  }
}

/**
 * [Please add a description.]
 */

function replaceInline(nodes) {
  this.resync();

  if (Array.isArray(nodes)) {
    if (Array.isArray(this.container)) {
      nodes = this._verifyNodeList(nodes);
      this._containerInsertAfter(nodes);
      return this.dangerouslyRemove();
    } else {
      return this.replaceWithMultiple(nodes);
    }
  } else {
    return this.replaceWith(nodes);
  }
}