Enhance testing for the short term fee model

bootloader/tests/bootloader/bootloader_test.yul

@@ -50,3 +50,51 @@ function TEST_simple_transaction() {
     let innerTxDataOffset := add(txDataOffset, 0x20)
     testing_assertEq(getGasPerPubdataByteLimit(innerTxDataOffset), 0xc350, "Invalid pubdata limit")
 }
+
+function TEST_getTransactionUpfrontOverhead() {
+    // For very large transactions it should be proportional to the memory,
+    // but for small ones, the transaction slots are more important
+
+    let smallTxOverhead := getTransactionUpfrontOverhead(32)
+    let largeTxOverhead := getTransactionUpfrontOverhead(1000000)
+
+    testing_assertEq(smallTxOverhead, TX_SLOT_OVERHEAD_GAS(), "Invalid small tx overhead")
+    testing_assertEq(largeTxOverhead, mul(1000000, MEMORY_OVERHEAD_GAS()), "Invalid small tx overhead")
+}
+
+function TEST_getFeeParams_HighPubdataPrice() {
+    // Under very large L1 gas price, the L2 base fee will start rising to ensure the 
+    // boundary on the gasLimit
+
+    // 15k gwei L1 pubdata price
+    let veryHighL1PubdataPrice := 15000000000000
+    // 0.1 gwei L2 base fee
+    let l2GasPrice := 100000000
+
+    let baseFee, gasPricePerPubdata := getFeeParams(
+        veryHighL1PubdataPrice,
+        // 0.1 gwei L2 base fee
+        l2GasPrice
+    )
+
+    testing_assertEq(baseFee, div(veryHighL1PubdataPrice, MAX_L2_GAS_PER_PUBDATA()), "Invalid base fee")
+    testing_assertEq(gasPricePerPubdata, MAX_L2_GAS_PER_PUBDATA(), "Invalid gasPricePerPubdata")
+}
+
+function TEST_getFeeParams_LowPubdataPrice() {
+    // Under low to medium pubdata price, the baseFee is equal to the fair gas price, 
+    // while the gas per pubdata pubdata is derived by strict division 
+
+    // 0.2 gwei L1 pubdata price
+    let veryLowL1GasPrice := 200000000
+    // 0.1 gwei L2 base fee
+    let l2GasPrice := 100000000
+
+    let baseFee, gasPricePerPubdata := getFeeParams(
+        veryLowL1GasPrice,
+        l2GasPrice
+    )
+
+    testing_assertEq(baseFee, l2GasPrice, "Invalid base fee")
+    testing_assertEq(gasPricePerPubdata, div(veryLowL1GasPrice, l2GasPrice), "Invalid gasPricePerPubdata")
+}