linehub fix for blockNumbers older then subgraph block start

[sdcrypt0]

Title:

• Pattern for PR title "protocol_name : protocol_category : other comments". Example - "uniswap: dex : tvl by user"

Checklist before requesting a review

1. index.ts file

   • Contains function

      ```export const getUserTVLByBlock = async (blocks: BlockData) => {
          const { blockNumber, blockTimestamp } = blocks
              //    Retrieve data using block number and timestamp
              // YOUR LOGIC HERE
          
          return csvRows
     
      };
      ``` 
     

   • getUserTVLByBlock function takes input with this schema

       ``` 
           interface BlockData {
               blockNumber: number;
               blockTimestamp: number;
           }
       ```
     

   • getUserTVLByBlock function returns output in this schema

           ```
           const csvRows: OutputDataSchemaRow[] = [];
     
           type OutputDataSchemaRow = {
               block_number: number;  //block_number which was given as input
               timestamp: number;     // block timestamp which was given an input, epoch format
               user_address: string;   // wallet address, all lowercase
               token_address: string;  // token address all lowercase
               token_balance: bigint;  // token balance, raw amount. Please dont divide by decimals
               token_symbol: string; //token symbol should be empty string if it is not available
               usd_price: number; //assign 0 if not available
           };
           ```
     

   • contains function

       ```
           const readBlocksFromCSV = async (filePath: string): Promise<BlockData[]> => {
           const blocks: BlockData[] = [];
     
           await new Promise<void>((resolve, reject) => {
               fs.createReadStream(filePath)
               .pipe(csv()) // Specify the separator as '\t' for TSV files
               .on('data', (row) => {
                   const blockNumber = parseInt(row.number, 10);
                   const blockTimestamp = parseInt(row.timestamp, 10);
                   if (!isNaN(blockNumber) && blockTimestamp) {
                   blocks.push({ blockNumber: blockNumber, blockTimestamp });
                   }
               })
               .on('end', () => {
                   resolve();
               })
               .on('error', (err) => {
                   reject(err);
               });
           });
     
           return blocks;
           };
     
       ```
     

   • has this code

       ```
       readBlocksFromCSV('hourly_blocks.csv').then(async (blocks: any[]) => {
       console.log(blocks);
       const allCsvRows: any[] = []; 
     
       for (const block of blocks) {
           try {
               const result = await getUserTVLByBlock(block);
               allCsvRows.push(...result);
           } catch (error) {
               console.error(`An error occurred for block ${block}:`, error);
           }
       }
       await new Promise((resolve, reject) => {
           const ws = fs.createWriteStream(`outputData.csv`, { flags: 'w' });
           write(allCsvRows, { headers: true })
               .pipe(ws)
               .on("finish", () => {
               console.log(`CSV file has been written.`);
               resolve;
               });
       });
     
       }).catch((err) => {
       console.error('Error reading CSV file:', err);
       });
       ```
     

   • Your code is handling Pagination to make sure all data for a given block is returned

2. Output data

   • Created a folder test on the same level as src and put sample outputData.csv with 15-20 records generated by your code
   • Data is returned for underlying tokens only. Not for special tokens (lp/veTokens etc)
   • Follows the exact sequence mentioned in OutputDataSchemaRow . This is needed as we want same column ordering in output csv
   • Value of each field is :
     • block_number is same as input block number. This signifies TVL is as of this block_number.
     • timestamp is same as input timestamp. This signifies TVL is as of this timestamp. It is in epoch format.
     • user_address is in lowercase
     • token_address is in lowercase
     • token_balance is in raw amount. Please dont divide by decimals.
     • token_symbol value if present, empty string if value is not available.
     • usd_price if value is available, 0 if value is not available.