feat: env vars in path (#4)

* add: regex crate

* feat: add in ability to use {{ENV_VAR}} inside of the path

* chg: update documentation to include env var usage

Cargo.toml

@@ -21,6 +21,7 @@ keywords = [
 [dependencies]
 anyhow = "1.0.72"
 clap = { version="4.3.12", features=["derive"] }
+regex = "1.10.4"
 serde = {version = "1.0.171", features = ["derive"]}
 serde_json = "1.0.117"
 sha2 = "0.10.8"

README.md

@@ -15,7 +15,7 @@ A simple configurable cd wrapper that provides powerful utilities for customizin
 
 ## Features
 
-- **Per Directory Environment Variables**  
+- **Per Directory Environment Variables**
 - **Auto Load .env files in Directories**
 - **Auto Execute Commands in Directories**
 - **Per Directory Aliases**
@@ -178,7 +178,7 @@ dirs = [
 ]
 ```
 
-## Configuration 
+## Configuration
 ### Global Configuration Options
 ```toml
 [config]
@@ -244,6 +244,14 @@ dirs = [
 ]
 ```
 
+### Using CDWE Environment Variables in the paths
+
+If you want to use something like **$HOME** or any other environment variable
+set in a path, you can do so by wrapping the environment variable inside of
+`{{}}`. Using **$HOME** as an example, you would do {{HOME}}. This can make
+using one cdwe.toml across many machines nice if you have different users but a
+similar directory structure for each user.
+
 ## Uninstalling
 1. Run cdwe-remove to clean up all shell artifacts
 ```bash

src/cache.rs

@@ -23,6 +23,19 @@ pub struct Cache {
     values: DirCacheMap,
 }
 
+/// Inserts any cdwe path environment variables into itself and returns
+/// updated path
+fn insert_env_var_into_path(re: &regex::Regex, path: &str) -> String {
+    re.replace_all(path, |caps: &regex::Captures| {
+        if let Some(value) = std::env::var(&caps[1]).ok() {
+            value // If the env var exists, replace with its value
+        } else {
+            caps[0].to_string() // If not, keep the original text
+        }
+    })
+    .to_string()
+}
+
 impl Cache {
     pub fn new(shell: String, hash: String, values: DirCacheMap) -> Self {
         Cache {
@@ -35,6 +48,9 @@ impl Cache {
     pub fn from_config(config: &Config, config_hash: &str) -> Self {
         let mut values: DirCacheMap = HashMap::new();
 
+        // Captures the content within {{}}
+        let re = regex::Regex::new(r"\{\{(.*?)\}\}").unwrap();
+
         for directory in &config.directories {
             let variables: Vec<EnvVariable> = match &directory.vars {
                 Some(EnvVariableStruct::HashMap(hash_map)) => hash_map
@@ -67,7 +83,8 @@ impl Cache {
                 aliases,
             };
 
-            values.insert(directory.path.clone(), dir_cache);
+            let result = insert_env_var_into_path(&re, directory.path.as_str());
+            values.insert(result, dir_cache);
         }
 
         let shell = match &config.config {
@@ -116,3 +133,31 @@ pub fn write_cache(cache: &Cache, home: &str) -> Result<()> {
 
     Ok(())
 }
+
+#[cfg(test)]
+mod tests {
+    use super::insert_env_var_into_path;
+
+    #[test]
+    fn test_insert_env_var_into_path() {
+        let re = regex::Regex::new(r"\{\{(.*?)\}\}").unwrap();
+        std::env::set_var("TEST_HOME", "/home/user");
+        std::env::set_var("TEST_NAME", "testing");
+        assert_eq!(
+            insert_env_var_into_path(&re, "{{TEST_HOME}}/testing"),
+            "/home/user/testing"
+        );
+        assert_eq!(
+            insert_env_var_into_path(&re, "{{TEST_HOME}}/{{TEST_NAME}}"),
+            "/home/user/testing"
+        );
+        assert_eq!(
+            insert_env_var_into_path(&re, "{{DOES_NOT_EXIST}}/{{TEST_NAME}}"),
+            "{{DOES_NOT_EXIST}}/testing"
+        );
+        assert_eq!(
+            insert_env_var_into_path(&re, "/home/user/testing"),
+            "/home/user/testing"
+        );
+    }
+}