_getPropertyAssignmentStatement.js

  _getPropertyAssignmentStatement(
    location: BabelNodeLVal,
    value: Value,
    mightHaveBeenDeleted: boolean,
    deleteIfMightHaveBeenDeleted: boolean = false
  ): BabelNodeStatement {
    if (mightHaveBeenDeleted) {
      // We always need to serialize this value in order to keep the invariants happy.
      let serializedValue = this.serializeValue(value);
      let condition;
      if (value instanceof AbstractValue && value.kind === "conditional") {
        let cf = this.conditionalFeasibility.get(value);
        invariant(cf !== undefined);
        let conditionalSerializedValue;
        if (cf.t && !cf.f) {
          conditionalSerializedValue = this.serializeValue(value.args[1]);
        } else if (!cf.t && cf.f) {
          conditionalSerializedValue = this.serializeValue(value.args[2]);
        } else {
          invariant(cf.t && cf.f);
        }
        if (conditionalSerializedValue !== undefined) {
          return t.expressionStatement(t.assignmentExpression("=", location, conditionalSerializedValue));
        }
        let [c, x, y] = value.args;
        if (x instanceof EmptyValue) {
          if (c instanceof AbstractValue && c.kind === "!") condition = this.serializeValue(c.args[0]);
          else condition = t.unaryExpression("!", this.serializeValue(c));
          serializedValue = this.serializeValue(y);
        } else if (y instanceof EmptyValue) {
          condition = this.serializeValue(c);
          serializedValue = this.serializeValue(x);
        }
      }
      if (condition === undefined) {
        condition = t.binaryExpression("!==", this.serializeValue(value), this._serializeEmptyValue());
      }
      let assignment = t.expressionStatement(t.assignmentExpression("=", location, serializedValue));
      let deletion = null;
      if (deleteIfMightHaveBeenDeleted) {
        invariant(location.type === "MemberExpression");
        deletion = t.expressionStatement(
          t.unaryExpression("delete", ((location: any): BabelNodeMemberExpression), true)
        );
      }
      return t.ifStatement(condition, assignment, deletion);
    } else {
      return t.expressionStatement(t.assignmentExpression("=", location, this.serializeValue(value)));
    }
  }