chore: simplify, skip fast fail test if cpus < 2 (#11336)

* chore: simplify, skip fast fail test if cpus < 2

* use std

Author: grandizzy

crates/forge/tests/cli/config.rs

@@ -26,6 +26,7 @@ use std::{
     fs,
     path::{Path, PathBuf},
     str::FromStr,
+    thread,
 };
 
 // tests all config values that are in use
@@ -1881,41 +1882,29 @@ forgetest_init!(test_exclude_lints_config, |prj, cmd| {
 
 // <https://github.com/foundry-rs/foundry/issues/6529>
 forgetest_init!(test_fail_fast_config, |prj, cmd| {
+    // Skip if we don't have at least 2 CPUs to run both tests in parallel.
+    if thread::available_parallelism().map_or(1, |n| n.get()) < 2 {
+        return;
+    }
+
+    prj.wipe_contracts();
     prj.update_config(|config| {
         // Set large timeout for fuzzed tests so test campaign won't stop if fail fast not passed.
         config.fuzz.timeout = Some(3600);
-        config.invariant.timeout = Some(3600);
     });
     prj.add_test(
         "AnotherCounterTest.sol",
         r#"
 import {Test} from "forge-std/Test.sol";
 
-contract InvariantHandler is Test {
-    function fuzz_selector(uint256 x) public {
-    }
-}
-
 contract AnotherCounterTest is Test {
-    uint256[] public fixtureAmount = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10];
-
-    function setUp() public {
-        new InvariantHandler();
-    }
     // This failure should stop all other tests.
     function test_Failure() public pure {
         require(false);
     }
 
     function testFuzz_SetNumber(uint256 x) public {
     }
-
-    function invariant_SetNumber() public {
-    }
-
-    function table_SetNumber(uint256 amount) public {
-        require(amount < 100);
-    }
 }
 "#,
     )