feat(cheatcodes): implement new cheatcode to check if a string contains another string

crates/cheatcodes/spec/src/vm.rs

@@ -1522,6 +1522,10 @@ interface Vm {
         string calldata error
     ) external pure;
 
+    /// Asserts that a string contains another string.
+    #[cheatcode(group = Testing, safety = Safe)]
+    function assertContains(string calldata haystack, string calldata needle) external pure;
+
     // ======== OS and Filesystem ========
 
     // -------- Metadata --------

crates/cheatcodes/src/test/assert.rs

@@ -1,4 +1,4 @@
-use crate::{CheatcodesExecutor, CheatsCtxt, Result, Vm::*};
+use crate::{Cheatcode, Cheatcodes, CheatcodesExecutor, CheatsCtxt, Result, Vm::*};
 use alloy_primitives::{hex, I256, U256};
 use foundry_evm_core::{
     abi::{format_units_int, format_units_uint},
@@ -447,6 +447,17 @@ impl_assertions! {
     (assertApproxEqRelDecimal_2Call, assertApproxEqRelDecimal_3Call),
 }
 
+impl Cheatcode for assertContainsCall {
+    fn apply(&self, _state: &mut Cheatcodes) -> Result {
+        let Self { haystack, needle } = self;
+        if haystack.contains(needle) {
+            Ok(Default::default())
+        } else {
+            Err(format!("String '{haystack}' does not contain '{needle}'").into())
+        }
+    }
+}
+
 fn assert_true(condition: bool) -> Result<Vec<u8>, SimpleAssertionError> {
     if condition {
         Ok(Default::default())

testdata/default/cheats/Assert.t.sol

@@ -822,4 +822,13 @@ contract AssertionsTest is DSTest {
 
         vm.assertApproxEqRel(uint256(0), uint256(0), uint256(0));
     }
+
+    function testAssertContains() public {
+        string memory str1 = "this is a test";
+        string memory str2 = "test";
+        string memory str3 = "foundry";
+        vm.assertContains(str1, str2);
+        vm._expectCheatcodeRevert(bytes(string.concat("String '", str1, "' does not contain '", str3, "'")));
+        vm.assertContains(str1, str3);
+    }
 }