fix(forge): detect invalid inline config keys

crates/config/src/inline/conf_parser.rs

@@ -2,6 +2,13 @@ use super::{remove_whitespaces, InlineConfigParserError};
 use crate::{inline::INLINE_CONFIG_PREFIX, InlineConfigError, NatSpec};
 use regex::Regex;
 
+/// Used to detect invalid configuration keys in the inline config.
+///
+/// # Example
+///
+/// forge-config: default.fuzz.runs = 100 - `fuzz` is a valid key
+/// forge-config: default.wrong.runs = 100 - `wrong` is an invalid key
+const VALID_CONFIG_KEYS: [&str; 2] = ["fuzz", "invariant"];
 /// This trait is intended to parse configurations from
 /// structured text. Foundry users can annotate Solidity test functions,
 /// providing special configs just for the execution of a specific test.
@@ -41,10 +48,27 @@ where
     fn merge(&self, natspec: &NatSpec) -> Result<Option<Self>, InlineConfigError> {
         let config_key = Self::config_key();
 
-        let configs = natspec
-            .current_profile_configs()
-            .filter(|l| l.contains(&config_key))
-            .collect::<Vec<String>>();
+        let mut configs = Vec::new();
+        for line in natspec.current_profile_configs() {
+            if !VALID_CONFIG_KEYS.iter().any(|&key| line.contains(key)) {
+                let wrong_key = line
+                    .split('.')
+                    .nth(1) // Get the part after the first dot (profile.KEY.value)
+                    .unwrap_or("unknown-config-key")
+                    .to_string();
+                return Err(InlineConfigError {
+                    line,
+                    source: InlineConfigParserError::InvalidConfigKey(
+                        wrong_key,
+                        format!("{VALID_CONFIG_KEYS:?}"),
+                    ),
+                });
+            }
+
+            if line.contains(&config_key) {
+                configs.push(line);
+            }
+        }
 
         self.try_merge(&configs).map_err(|e| {
             let line = natspec.debug_context();

crates/config/src/inline/error.rs

@@ -5,6 +5,9 @@ pub enum InlineConfigParserError {
     /// The property cannot be mapped to the configuration object
     #[error("'{0}' is an invalid config property")]
     InvalidConfigProperty(String),
+    /// An invalid config key has been provided
+    #[error("'{0}' is an invalid config key. Available config keys are: {1}")]
+    InvalidConfigKey(String, String),
     /// An invalid profile has been provided
     #[error("'{0}' specifies an invalid profile. Available profiles are: {1}")]
     InvalidProfile(String, String),

crates/config/src/lib.rs

@@ -108,7 +108,10 @@ mod invariant;
 pub use invariant::InvariantConfig;
 
 mod inline;
-pub use inline::{validate_profiles, InlineConfig, InlineConfigError, InlineConfigParser, NatSpec};
+pub use inline::{
+    validate_profiles, InlineConfig, InlineConfigError, InlineConfigParser,
+    InlineConfigParserError, NatSpec,
+};
 
 pub mod soldeer;
 use soldeer::{SoldeerConfig, SoldeerDependencyConfig};

crates/forge/tests/it/inline.rs

@@ -3,7 +3,7 @@
 use crate::test_helpers::{ForgeTestData, ForgeTestProfile, TEST_DATA_DEFAULT};
 use forge::{result::TestKind, TestOptionsBuilder};
 use foundry_config::{FuzzConfig, InvariantConfig};
-use foundry_test_utils::Filter;
+use foundry_test_utils::{forgetest_init, Filter};
 
 #[tokio::test(flavor = "multi_thread")]
 async fn inline_config_run_fuzz() {
@@ -98,3 +98,30 @@ fn build_test_options_just_one_valid_profile() {
     // per-test configs for "default" and "ci" profiles
     assert!(build_result.is_err());
 }
+
+forgetest_init!(tests_invalid_config_key, |prj, cmd| {
+    prj.wipe_contracts();
+
+    prj.insert_ds_test();
+
+    prj.add_test(
+        "InvalidInlineConf.t.sol",
+        r#"
+        import {Test} from "forge-std/Test.sol";
+
+        contract InvalidInlineConf is Test {
+            /// forge-config: default.fuzz.runs = 1024
+            /// forge-config: default.invalid.runs = 1024
+            function testInvalidInlineConf() public {}
+        }
+    "#,
+    )
+    .unwrap();
+
+    cmd.args(["test", "--mt", "testInvalidInlineConf"]).assert_failure().stderr_eq(
+        r#"Error: Inline config error detected at forge-config:default.invalid.runs=1024
+
+Context:
+- 'invalid' is an invalid config key. Available config keys are: [..]"#,
+    );
+});