fix: correct type and documentation for baseFeePerGas at web3.eth.getFeeHistory (#7291)

* update type and documentation for `baseFeePerGas` at `web3.eth.getFeeHistory`

* fix a type at a unit test

Author: Muhammad-Altabba

docs/docs/guides/web3_upgrade_guide/1.x/web3_eth_migration_guide.md

@@ -147,7 +147,7 @@ web3.eth.getHashRate // -> correct usage
 
 #### web3.eth.getFeeHistory
 
-4.x returns a `BigInt` for `oldestBlock` instead of the hex string that's returned in 1.x.
+4.x returns a `BigInt` for `oldestBlock` instead of the hex string that's returned in 1.x. And 4.x returns `number[]`, instead of `strings[]` for `baseFeePerGas`.
 
 ```typescript
 // in 1.x
@@ -162,7 +162,7 @@ await web3.eth.getFeeHistory('0x1', 'latest', []);
 await web3.eth.getFeeHistory('0x1', 'latest', []);
 // {
 //     oldestBlock: 0n,
-//     baseFeePerGas: [ '0x3b9aca00', '0x342770c0' ],
+//     baseFeePerGas: [ 1000000000, 875000000 ],
 //     gasUsedRatio: [ 0 ]
 // }
 ```

packages/web3-eth/test/unit/rpc_method_wrappers/fixtures/get_fee_history.ts

@@ -18,7 +18,7 @@ import { FeeHistoryResultAPI, BlockNumberOrTag, BlockTags, Numbers } from 'web3-
 
 export const mockRpcResponse: FeeHistoryResultAPI = {
 	oldestBlock: '0xa30950',
-	baseFeePerGas: '0x9',
+	baseFeePerGas: ['0x9'],
 	reward: [],
 	gasUsedRatio: ['0'],
 };

packages/web3-types/CHANGELOG.md

@@ -209,3 +209,7 @@ Documentation:
 -   Add COMMITTED to BlockTags (#7124)
 
 ## [Unreleased]
+
+### Changed
+
+-   update the type for `baseFeePerGas` at `web3.eth.getFeeHistory` to be a number. (#7291)

packages/web3-types/src/eth_types.ts

@@ -515,7 +515,7 @@ export type Block = BlockBase<
 
 export interface FeeHistoryBase<NumberType> {
 	readonly oldestBlock: NumberType;
-	readonly baseFeePerGas: NumberType;
+	readonly baseFeePerGas: NumberType[];
 	readonly reward: NumberType[][];
 	readonly gasUsedRatio: NumberType[];
 }