feat(config): extend rpc endpoint support

config/README.md

@@ -143,6 +143,28 @@ stackAllocation = true
 optimizerSteps = 'dhfoDgvulfnTUtnIf'
 ```
 
+##### RPC-Endpoints settings
+
+The `rpc_endpoints` value accepts a list of `alias = "<url|env var>"` pairs.
+
+The following example declares two pairs:
+The alias `optimism` references the endpoint URL directly.
+The alias `mainnet` references the environment variable `RPC_MAINNET` which holds the actual URL.
+
+Environment variables need to be wrapped in `${}`
+
+```toml
+rpc_endpoints = { optimism = "https://optimism.alchemyapi.io/v2/...", mainnet = "${RPC_MAINNET}" }
+```
+
+Alternatively the following form is accepted, note the `profile` prefix:
+
+```toml
+[default.rpc_endpoints]
+optimism = "https://optimism.alchemyapi.io/v2/..."
+mainnet = "${RPC_MAINNET}"
+```
+
 ##### Additional Model Checker settings
 
 [Solidity's built-in model checker](https://docs.soliditylang.org/en/latest/smtchecker.html#tutorial)

config/src/lib.rs

@@ -41,7 +41,7 @@ pub mod utils;
 pub use crate::utils::*;
 
 mod rpc;
-pub use rpc::RpcEndpoints;
+pub use rpc::{ResolvedRpcEndpoints, RpcEndpoint, RpcEndpoints, UnresolvedEnvVarError};
 
 pub mod cache;
 use cache::{Cache, ChainCache};
@@ -2503,6 +2503,10 @@ mod tests {
                 chains = 'all'
                 endpoints = 'all'
 
+                [default.rpc_endpoints]
+                optimism = "https://example.com/"
+                mainnet = "${RPC_MAINNET}"
+
             "#,
             )?;
 
@@ -2512,6 +2516,14 @@ mod tests {
                 vec![Remapping::from_str("nested/=lib/nested/").unwrap().into()]
             );
 
+            assert_eq!(
+                config.rpc_endpoints,
+                RpcEndpoints::new([
+                    ("optimism", RpcEndpoint::Url("https://example.com/".to_string())),
+                    ("mainnet", RpcEndpoint::Env("RPC_MAINNET".to_string()))
+                ]),
+            );
+
             Ok(())
         });
     }

config/src/rpc.rs

@@ -1,7 +1,7 @@
 //! Support for multiple RPC-endpoints
 
 use serde::{Deserialize, Deserializer, Serialize, Serializer};
-use std::{collections::BTreeMap, env, env::VarError, fmt};
+use std::{collections::BTreeMap, env, env::VarError, fmt, ops::Deref};
 
 /// Container type for rpc endpoints
 #[derive(Debug, Clone, PartialEq, Eq, Default, Serialize, Deserialize)]
@@ -24,12 +24,18 @@ impl RpcEndpoints {
     }
 
     /// Returns all (alias -> url) pairs
-    ///
-    /// # Errors
-    ///
-    /// returns an error if it contains a reference to an env var that is not set
-    pub fn resolve_all(self) -> Result<BTreeMap<String, String>, VarError> {
-        self.endpoints.into_iter().map(|(name, e)| (e.resolve().map(|url| (name, url)))).collect()
+    pub fn resolved(self) -> ResolvedRpcEndpoints {
+        ResolvedRpcEndpoints {
+            endpoints: self.endpoints.into_iter().map(|(name, e)| (name, e.resolve())).collect(),
+        }
+    }
+}
+
+impl Deref for RpcEndpoints {
+    type Target = BTreeMap<String, RpcEndpoint>;
+
+    fn deref(&self) -> &Self::Target {
+        &self.endpoints
     }
 }
 
@@ -43,7 +49,7 @@ impl RpcEndpoints {
 pub enum RpcEndpoint {
     /// A raw Url (ws, http)
     Url(String),
-    // Reference to an env var in the form of `${ENV_VAR}`
+    /// Reference to an env var in the form of `${ENV_VAR}`
     Env(String),
 }
 
@@ -71,10 +77,12 @@ impl RpcEndpoint {
     /// # Error
     ///
     /// Returns an error if the type holds a reference to an env var and the env var is not set
-    pub fn resolve(self) -> Result<String, VarError> {
+    pub fn resolve(self) -> Result<String, UnresolvedEnvVarError> {
         match self {
             RpcEndpoint::Url(url) => Ok(url),
-            RpcEndpoint::Env(v) => env::var(v),
+            RpcEndpoint::Env(var) => {
+                env::var(&var).map_err(|source| UnresolvedEnvVarError { var, source })
+            }
         }
     }
 }
@@ -91,7 +99,7 @@ impl fmt::Display for RpcEndpoint {
 }
 
 impl TryFrom<RpcEndpoint> for String {
-    type Error = VarError;
+    type Error = UnresolvedEnvVarError;
 
     fn try_from(value: RpcEndpoint) -> Result<Self, Self::Error> {
         value.resolve()
@@ -123,6 +131,43 @@ impl<'de> Deserialize<'de> for RpcEndpoint {
     }
 }
 
+/// Container type for _resolved_ RPC endpoints, see [RpcEndpoints::resolve_all()]
+#[derive(Debug, Clone, PartialEq, Eq, Default)]
+pub struct ResolvedRpcEndpoints {
+    /// contains all named endpoints and their URL or an error if we failed to resolve the env var
+    /// alias
+    endpoints: BTreeMap<String, Result<String, UnresolvedEnvVarError>>,
+}
+
+impl Deref for ResolvedRpcEndpoints {
+    type Target = BTreeMap<String, Result<String, UnresolvedEnvVarError>>;
+
+    fn deref(&self) -> &Self::Target {
+        &self.endpoints
+    }
+}
+
+/// Error when we failed to resolve an env var
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct UnresolvedEnvVarError {
+    /// Var that couldn't be resolved
+    pub var: String,
+    /// the `env::var` error
+    pub source: VarError,
+}
+
+impl fmt::Display for UnresolvedEnvVarError {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(f, "Failed to resolve env var `{}`: {}", self.var, self.source)
+    }
+}
+
+impl std::error::Error for UnresolvedEnvVarError {
+    fn source(&self) -> Option<&(dyn std::error::Error + 'static)> {
+        Some(&self.source)
+    }
+}
+
 /// Extracts the value surrounded by `${<val>}`
 ///
 /// TODO(mattsse): make this a bit more sophisticated

evm/src/executor/inspector/cheatcodes/config.rs

@@ -1,7 +1,10 @@
 use crate::executor::opts::EvmOpts;
-use foundry_config::{cache::StorageCachingConfig, Config, RpcEndpoints};
+use bytes::Bytes;
+use foundry_config::{cache::StorageCachingConfig, Config, ResolvedRpcEndpoints};
 use std::path::{Path, PathBuf};
 
+use super::util;
+
 /// Additional, configurable context the `Cheatcodes` inspector has access to
 ///
 /// This is essentially a subset of various `Config` settings `Cheatcodes` needs to know.
@@ -13,13 +16,16 @@ pub struct CheatsConfig {
     /// RPC storage caching settings determines what chains and endpoints to cache
     pub rpc_storage_caching: StorageCachingConfig,
     /// All known endpoints and their aliases
-    pub rpc_endpoints: RpcEndpoints,
+    pub rpc_endpoints: ResolvedRpcEndpoints,
 
     /// Project root
     pub root: PathBuf,
 
     /// Paths (directories) where file reading/writing is allowed
     pub allowed_paths: Vec<PathBuf>,
+
+    /// How the evm was configured by the user
+    pub evm_opts: EvmOpts,
 }
 
 // === impl CheatsConfig ===
@@ -34,9 +40,10 @@ impl CheatsConfig {
         Self {
             ffi: evm_opts.ffi,
             rpc_storage_caching: config.rpc_storage_caching.clone(),
-            rpc_endpoints: config.rpc_endpoints.clone(),
+            rpc_endpoints: config.rpc_endpoints.clone().resolved(),
             root: config.__root.0.clone(),
             allowed_paths,
+            evm_opts: evm_opts.clone(),
         }
     }
 
@@ -51,4 +58,30 @@ impl CheatsConfig {
 
         Ok(())
     }
+
+    /// Returns the RPC to use
+    ///
+    /// If `url_or_alias` is a known alias in the `ResolvedRpcEndpoints` then it returns the
+    /// corresponding URL of that alias. otherwise this assumes `url_or_alias` is itself a URL
+    /// if it starts with a `http` or `ws` scheme
+    ///
+    /// # Errors
+    ///
+    ///  - Returns an error if `url_or_alias` is a known alias but references an unresolved env var.
+    ///  - Returns an error if `url_or_alias` is not an alias but does not start with a `http` or
+    ///    `scheme`
+    pub fn get_rpc_url(&self, url_or_alias: impl Into<String>) -> Result<String, Bytes> {
+        let url_or_alias = url_or_alias.into();
+        match self.rpc_endpoints.get(&url_or_alias) {
+            Some(Ok(url)) => Ok(url.clone()),
+            Some(Err(err)) => Err(util::encode_error(err)),
+            None => {
+                if !url_or_alias.starts_with("http") && !url_or_alias.starts_with("ws") {
+                    Err(util::encode_error(format!("invalid rpc url {}", url_or_alias)))
+                } else {
+                    Ok(url_or_alias)
+                }
+            }
+        }
+    }
 }