# TokenValidator

Validates tokens by flash borrowing from the token/ pool on V1.

Returns Status.FOT if we detected a fee is taken on transfer. Status.STF if transfer failed for the token. Status.UNKN if we did not detect any issues with the token.

A return value of Status.UNKN does not mean the token is definitely not a fee on transfer token or definitely has no problems with its transfer. It just means we cant say for sure that it has any issues.

*We can not guarantee the result of this lens is correct for a few reasons:*

*1/ Some tokens take fees or allow transfers under specific conditions, for example some have an allowlist*

*of addresses that do/dont require fees. Therefore the result is not guaranteed to be correct*

*in all circumstances.*

*2/ It is possible that the token does not have any pools on V1 therefore we are not able to perform*

*a flashloan to test the token.*

### State Variables <a href="#state-variables" id="state-variables"></a>

#### FOT\_REVERT\_STRING <a href="#fot_revert_string" id="fot_revert_string"></a>

```solidity
string internal constant FOT_REVERT_STRING = "FOT";
```

#### STF\_REVERT\_STRING\_SUFFIX <a href="#stf_revert_string_suffix" id="stf_revert_string_suffix"></a>

```solidity
string internal constant STF_REVERT_STRING_SUFFIX = "TRANSFER_FAILED";
```

### Functions <a href="#functions" id="functions"></a>

#### constructor <a href="#constructor" id="constructor"></a>

```solidity
constructor(address _factoryV1, address _positionManager) ImmutableState(_factoryV1, _positionManager);
```

#### batchValidate <a href="#batchvalidate" id="batchvalidate"></a>

```solidity
function batchValidate(address[] calldata tokens, address[] calldata baseTokens, uint256 amountToBorrow)
    public
    override
    returns (Status[] memory isFotResults);
```

#### validate <a href="#validate" id="validate"></a>

```solidity
function validate(address token, address[] calldata baseTokens, uint256 amountToBorrow)
    public
    override
    returns (Status);
```

#### \_validate <a href="#validate" id="validate"></a>

```solidity
function _validate(address token, address baseToken, uint256 amountToBorrow) internal returns (Status);
```

#### isFotFailed <a href="#isfotfailed" id="isfotfailed"></a>

```solidity
function isFotFailed(string memory reason) internal pure returns (bool);
```

#### isTransferFailed <a href="#istransferfailed" id="istransferfailed"></a>

```solidity
function isTransferFailed(string memory reason) internal pure returns (bool);
```

#### dragonswapCall <a href="#dragonswapcall" id="dragonswapcall"></a>

```solidity
function dragonswapCall(address, uint256 amount0, uint256, bytes calldata data) external view override;
```


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://docs.dragonswap.app/dragonswap/resources/developer-resources/smart-contracts/dragonswapv2/smart-router/lens/tokenvalidator.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.