randomBytes (#55)

* add randomUint256 function to suavelib

* add randomBytes precompile handler

* add randomUintX functions, deprecate randomUint256 precompile call

* remove randomUint256 precompile address

* Done

---------

Co-authored-by: Ferran Borreguero <[email protected]>

src/Random.sol

@@ -0,0 +1,48 @@
+// SPDX-License-Identifier: UNLICENSED
+pragma solidity ^0.8.8;
+
+import "./suavelib/Suave.sol";
+
+library Random {
+    function randomUint8() internal returns (uint8 value) {
+        bytes memory random = Suave.randomBytes(1);
+        assembly {
+            value := mload(add(random, 0x01))
+        }
+    }
+
+    function randomUint16() internal returns (uint16 value) {
+        bytes memory random = Suave.randomBytes(2);
+        assembly {
+            value := mload(add(random, 0x02))
+        }
+    }
+
+    function randomUint32() internal returns (uint32 value) {
+        bytes memory random = Suave.randomBytes(4);
+        assembly {
+            value := mload(add(random, 0x04))
+        }
+    }
+
+    function randomUint64() internal returns (uint64 value) {
+        bytes memory random = Suave.randomBytes(8);
+        assembly {
+            value := mload(add(random, 0x08))
+        }
+    }
+
+    function randomUint128() internal returns (uint128 value) {
+        bytes memory random = Suave.randomBytes(16);
+        assembly {
+            value := mload(add(random, 0x10))
+        }
+    }
+
+    function randomUint256() internal returns (uint256 value) {
+        bytes memory random = Suave.randomBytes(32);
+        assembly {
+            value := mload(add(random, 0x20))
+        }
+    }
+}

test/Random.t.sol

@@ -0,0 +1,52 @@
+// SPDX-License-Identifier: Unlicense
+pragma solidity ^0.8.0;
+
+import "forge-std/Test.sol";
+import {console2} from "forge-std/console2.sol";
+import "src/suavelib/Suave.sol";
+import "src/Random.sol";
+import "src/Test.sol";
+
+contract TestRandom is Test, SuaveEnabled {
+    function testRandomBytes() public {
+        bytes memory random = Suave.randomBytes(32);
+        console2.logBytes(random);
+        assert(random.length == 32);
+    }
+
+    function testRandomUint8() public {
+        uint8 random = Random.randomUint8();
+        console2.log("random uint8: %d", random);
+        assert(random > 0);
+    }
+
+    function testRandomUint16() public {
+        uint16 random = Random.randomUint16();
+        console2.log("random uint16: %d", random);
+        assert(random > 0);
+    }
+
+    function testRandomUint32() public {
+        uint32 random = Random.randomUint32();
+        console2.log("random uint32: %d", random);
+        assert(random > 0);
+    }
+
+    function testRandomUint64() public {
+        uint64 random = Random.randomUint64();
+        console2.log("random uint64: %d", random);
+        assert(random > 0);
+    }
+
+    function testRandomUint128() public {
+        uint128 random = Random.randomUint128();
+        console2.log("random uint128: %d", random);
+        assert(random > 0);
+    }
+
+    function testRandomUint256() public {
+        uint256 random = Random.randomUint256();
+        console2.log("random uint256: %d", random);
+        assert(random > 0);
+    }
+}