chore(avm): Test cleanup and update yp to allow for zero gas

yarn-project/simulator/src/avm/avm_simulator.test.ts

@@ -42,12 +42,10 @@ describe('AVM simulator: injected bytecode', () => {
     const context = initContext({ env: initExecutionEnvironment({ calldata }) });
     const { l2GasLeft: initialL2GasLeft } = AvmMachineState.fromState(context.machineState);
     const results = await new AvmSimulator(context).executeBytecode(bytecode);
-    const expectedL2GasUsed = ops.reduce((sum, op) => sum + op.gasCost().l2Gas, 0);
 
     expect(results.reverted).toBe(false);
     expect(results.output).toEqual([new Fr(3)]);
-    expect(expectedL2GasUsed).toBeGreaterThan(0);
-    expect(context.machineState.l2GasLeft).toEqual(initialL2GasLeft - expectedL2GasUsed);
+    expect(context.machineState.l2GasLeft).toEqual(initialL2GasLeft - 30);
   });
 
   it('Should halt if runs out of gas', async () => {
@@ -60,6 +58,9 @@ describe('AVM simulator: injected bytecode', () => {
     expect(results.reverted).toBe(true);
     expect(results.output).toEqual([]);
     expect(results.revertReason?.name).toEqual('OutOfGasError');
+    expect(context.machineState.l2GasLeft).toEqual(0);
+    expect(context.machineState.l1GasLeft).toEqual(0);
+    expect(context.machineState.daGasLeft).toEqual(0);
   });
 });
 

yarn-project/simulator/src/avm/opcodes/instruction.ts

@@ -29,7 +29,7 @@ export abstract class Instruction {
    * Loads default gas cost for the instruction from the GasCosts table.
    * Instruction sub-classes can override this if their gas cost is not fixed.
    */
-  public gasCost(): GasCost {
+  protected gasCost(): GasCost {
     return GasCosts[this.opcode] ?? EmptyGasCost;
   }
 

yellow-paper/docs/public-vm/execution.md

@@ -85,9 +85,9 @@ chargeGas(context, l1GasCost, l2GasCost, daGasCost)
 
 Before an instruction is executed, the VM enforces that there is sufficient gas remaining via the following assertions:
 ```
-assert machineState.l1GasLeft - instr.l1GasCost > 0
-assert machineState.l2GasLeft - instr.l2GasCost > 0
-assert machineState.daGasLeft - instr.daGasCost > 0
+assert machineState.l1GasLeft - instr.l1GasCost >= 0
+assert machineState.l2GasLeft - instr.l2GasCost >= 0
+assert machineState.daGasLeft - instr.daGasCost >= 0
 ```
 
 > Many instructions (like arithmetic operations) have 0 `l1GasCost` and `daGasCost`. Instructions only incur an L1 or DA cost if they modify the [world state](./state#avm-world-state) or [accrued substate](./state#accrued-substate).
@@ -163,9 +163,9 @@ The AVM's exceptional halting conditions area listed below:
 
 1. **Insufficient gas**
     ```
-    assert machineState.l1GasLeft - instr.l1GasCost > 0
-    assert machineState.l2GasLeft - instr.l2GasCost > 0
-    assert machineState.daGasLeft - instr.l2GasCost > 0
+    assert machineState.l1GasLeft - instr.l1GasCost >= 0
+    assert machineState.l2GasLeft - instr.l2GasCost >= 0
+    assert machineState.daGasLeft - instr.l2GasCost >= 0
     ```
 1. **Invalid instruction encountered**
     ```