docs(sol): add docs and tests with notes on invalid inputs (#734)

# Rationale for this change

This improves documentation and test coverage.

Author: JayWhite2357

solidity/src/hyperkzg/HyperKZGHelpers.pre.sol

@@ -270,6 +270,7 @@ library HyperKZGHelpers {
     /// \\[ g_L := \left(d^2 + d + 1\right)\cdot \left(\mathbf{C} + \sum_{i=0}^{m-1} q^{i+1}\cdot \mathbf{com}_i\right)+
     ///     r\cdot\mathbf{w}_0 - dr \cdot\mathbf{w}_1 + (dr)^2\cdot\mathbf{w}_2 + b\cdot (-\mathbf{G}) \\]
     /// @dev The computation is performed using EC operations via precompiles in a specific order to optimize gas usage
+    /// @dev NOTE: this function's will revert if any of the EC inputs are invalid.
     /// @param __com Array of commitment points
     /// @param __w Array of witness points
     /// @param __commitment The commitment point C

solidity/src/hyperkzg/HyperKZGVerifier.pre.sol

@@ -99,6 +99,7 @@ library HyperKZGVerifier {
     /// * `commitment_ptr` - the memory pointer to the commitment point
     /// * `x` - the memory pointer to the array of x coordinates
     /// * `y` - the y value being verified
+    /// @dev NOTE: the method will always revert if `x` is empty, or if the proof is invalid.
     /// @dev This function verifies a HyperKZG proof by:*
     /// 1. Running a Fiat-Shamir transcript to generate challenges r, q, d
     /// WARNING: The public inputs (x, y, the commitments, digest of the KZG SRS, degree bound, etc) are

solidity/test/base/ECPrecompiles.t.pre.sol

@@ -119,6 +119,12 @@ contract ECPrecompilesTest is Test {
         assert(argsPtr[2] == e);
     }
 
+    function testFuzz01IsInvalidECPoint(uint256 e) public {
+        uint256[3] memory argsPtr = [uint256(0), 1, e];
+        vm.expectRevert(Errors.InvalidECMulInputs.selector);
+        ECPrecompilesTestWrapper.ecMul(argsPtr);
+    }
+
     function testRevertWhenECMulInvalidInput() public {
         uint256[3] memory argsPtr = [uint256(2), 3, 4];
         vm.expectRevert(Errors.InvalidECMulInputs.selector);

solidity/test/hyperkzg/HyperKZGHelpers.t.pre.sol

@@ -274,6 +274,45 @@ contract HyperKZGHelpersTest is Test {
         assert(scratch[1] == 0);
     }
 
+    function testComputeGLMSMWithLenOneRevertsWhenAnInputIsAnInvalidECPoint() public {
+        uint256[2][] memory com = new uint256[2][](1);
+        com[0] = [G1_NEG_GEN_X, G1_NEG_GEN_Y];
+        uint256[2][3] memory w;
+        w[0] = [uint256(0), 1];
+        w[1] = [uint256(0), 2];
+        w[2] = [uint256(0), 3];
+        uint256[2] memory commitment = [uint256(0), 0];
+        uint256[4] memory rqdb = [uint256(1), 1, 1, 1];
+        uint256[5] memory scratch;
+        vm.expectRevert(Errors.InvalidECMulInputs.selector);
+        scratch = HyperKZGHelpers.__computeGLMSM({
+            __com: com,
+            __w: w,
+            __commitment: commitment,
+            __rqdb: rqdb,
+            __scratch: scratch
+        });
+    }
+
+    function testComputeGLMSMWithLenOneDoesNotRevertWithValidInputs() public view {
+        uint256[2][] memory com = new uint256[2][](1);
+        com[0] = [G1_NEG_GEN_X, G1_NEG_GEN_Y];
+        uint256[2][3] memory w;
+        w[0] = [uint256(1), 2];
+        w[1] = [uint256(0), 0];
+        w[2] = [uint256(G1_GEN_X), G1_GEN_Y];
+        uint256[2] memory commitment = [uint256(0), 0];
+        uint256[4] memory rqdb = [uint256(1), 1, 1, 1];
+        uint256[5] memory scratch;
+        scratch = HyperKZGHelpers.__computeGLMSM({
+            __com: com,
+            __w: w,
+            __commitment: commitment,
+            __rqdb: rqdb,
+            __scratch: scratch
+        });
+    }
+
     function testComputeGLMSMWithSimpleValues() public view {
         uint256[2][] memory com = new uint256[2][](2);
         (uint256 comx, uint256 comy) = ECPrecompilesTestHelper.ecBasePower(2);