Add support for curly brackets when resolving envs (foundry-rs#2868)

<!-- Reference any GitHub issues resolved by this PR -->

Closes foundry-rs#2851

## Introduced changes

<!-- A brief description of the changes -->

- Added implementation for resolving environmental variables with curly
braces

## Checklist

<!-- Make sure all of these are complete -->

- [x] Linked relevant issue
- [x] Updated relevant documentation
- [x] Added relevant tests
- [x] Performed self-review of the code
- [ ] Added changes to `CHANGELOG.md`

---------

Co-authored-by: ddoktorski <45050160+ddoktorski@users.noreply.github.com>
Co-authored-by: Franciszek Job <54181625+franciszekjob@users.noreply.github.com>

crates/configuration/src/lib.rs

@@ -122,7 +122,12 @@ fn resolve_env_variables(config: serde_json::Value) -> Result<serde_json::Value>
 
 fn resolve_env_variable(var: &str) -> Result<serde_json::Value> {
     assert!(var.starts_with('$'));
-    let value = env::var(&var[1..])?;
+    let mut initial_value = &var[1..];
+    if initial_value.starts_with('{') && initial_value.ends_with('}') {
+        initial_value = &initial_value[1..initial_value.len() - 1];
+    }
+    let value = env::var(initial_value)?;
+
     if let Ok(value) = value.parse::<Number>() {
         return Ok(serde_json::Value::Number(value));
     }
@@ -308,6 +313,8 @@ mod tests {
         list_example: Vec<bool>,
         #[serde(default, rename(serialize = "url-nested", deserialize = "url-nested"))]
         url_nested: f32,
+        #[serde(default, rename(serialize = "url-alt", deserialize = "url-alt"))]
+        url_alt: String,
     }
 
     impl Config for StubComplexConfig {
@@ -355,6 +362,7 @@ mod tests {
 
         // present env variables
         env::set_var("VALUE_STRING123132", "nfsaufbnsailfbsbksdabfnkl");
+        env::set_var("VALUE_STRING123142", "nfsasnsidnnsailfbsbksdabdkdkl");
         env::set_var("VALUE_INT123132", "321312");
         env::set_var("VALUE_FLOAT123132", "321.312");
         env::set_var("VALUE_BOOL1231321", "true");
@@ -368,5 +376,9 @@ mod tests {
         assert_eq!(config.account, 321_312);
         assert_eq!(config.nested.list_example, vec![true, false]);
         assert_eq!(config.nested.url_nested, 321.312);
+        assert_eq!(
+            config.nested.url_alt,
+            String::from("nfsasnsidnnsailfbsbksdabdkdkl")
+        );
     }
 }

crates/configuration/tests/data/stubtool_snfoundry.toml

@@ -32,3 +32,4 @@ account = "$VALUE_INT123132"
 [stubtool.with-envs.nested]
 list-example = [ "$VALUE_BOOL1231321", "$VALUE_BOOL1231322"  ]
 url-nested = "$VALUE_FLOAT123132"
+url-alt = "${VALUE_STRING123142}"

docs/src/projects/configuration.md

@@ -160,7 +160,7 @@ the configuration from the local file will be used to override the global `defau
 
 ## Environmental Variables
 
-Programmers can use environmental variables in both `Scarb.toml::tool::snforge` and in `snfoundry.toml`. To use an environmental variable as a value, use its name prefixed with `$`. 
+Programmers can use environmental variables in both `Scarb.toml::tool::snforge` and in `snfoundry.toml`. To use an environmental variable as a value, use its name either with or without curly braces, prefixed with `$` (e.g. `${MY_ENV}` or `$MY_ENV`).
 This might be useful, for example, to hide node urls in the public repositories. 
 As an example: