Remix: How do I set the Gas Limit to Test a Contract?

Question

I am using the Javascript VM on remix.ethereum.org to learn Smart Contract basics.

I am following the tutorial here: https://www.youtube.com/watch?v=oTS9uxU6cAM&list=PLO5VPQH6OWdULDcret0S0EYQ7YcKzrigz&index=4

The tutorial demonstrates what happens when there is not enough Gas. At 05:29 the Gas Limit in Remix is set to 30000 and the transaction is shown to fail.

If I set the Gas Limit to 30000 it still executes successfully.

Here is my code (same as is in the tutorial):

// SPDX-License-Identifier: GPL-3.0

pragma solidity >=0.4.16 <= 0.8.6;

contract Gas {
    function testGasRefund() public view returns (uint) {
        return tx.gasprice;
    }
    
    uint public i = 0;
    
    function forever() public {
        while(true) {
            i += 1;
        }
    }
}

When I deploy the contract - the Gas shows as 80000000, the debug output shows:

status  true Transaction mined and execution succeed
 transaction hash   0xbc5cf5a7d535b2a4f6b6c84ae5adc00a46e9ef6403ebbc19f0266c573d529b21
 from   0x78731D3Ca6b7E34aC0F824c42a7cC18A495cabaB
 to Gas.(constructor)
 gas    80000000 gas
 transaction cost   80000000 gas
 execution cost 148581 gas
 hash   0xbc5cf5a7d535b2a4f6b6c84ae5adc00a46e9ef6403ebbc19f0266c573d529b21
 input  0x608...40033
 decoded input
 decoded output
 logs   []
 value  0 wei

Answer 1

It looks like remix gas limit doesn't apply to deployment and only to the function executions.