manplan-2 feature: could we allow for rules yaml to be driven by dot …

…file?

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "manplan"
-version = "0.1.3"
+version = "0.1.4"
 authors = ["Gerard Krupa"]
 edition = "2021"
 description = "Tool for keeping sdkman candidates up-to-date"
@@ -17,6 +17,7 @@ serde = { version = "1.0", features = ["derive"] }
 serde_yaml = "0.9"
 maplit = "1.0.2"
 clap = { version = "4.4.6", features = ["derive"] }
+expect-exit = "0.5.2"
 
 [profile.release]
 lto = "fat"

src/main.rs

@@ -1,7 +1,9 @@
 use std::collections::HashSet;
-use std::fs;
+use std::path::Path;
+use std::{env, fs};
 
 use clap::Parser;
+use expect_exit::Expected;
 
 use crate::rules::{parse_rules, VersionMatch};
 use crate::sdkman::{SdkMan, ToolManager};
@@ -14,7 +16,7 @@ pub mod sdkman;
 struct Args {
     /// Filename of the YAML config file
     #[arg(short, long)]
-    file: String,
+    file: Option<String>,
 
     /// Just print out the commands that would be executed
     #[arg(short, long, default_value_t = false)]
@@ -25,14 +27,31 @@ struct Args {
     no_uninstall: bool,
 }
 
+#[allow(clippy::needless_return)]
+fn get_rules_file(args: &Args) -> Option<String> {
+    if let Some(file) = args.file.as_ref() {
+        return Some(file.clone());
+    } else if let Ok(home) = env::var("HOME") {
+        let dotfile = Path::new(home.as_str()).join(".sdk-rules.yaml");
+        if dotfile.is_file() {
+            return Some(dotfile.to_str().unwrap().to_string());
+        }
+    }
+    return None;
+}
+
 fn main() {
     let args = Args::parse();
 
     let sdkman = SdkMan {
         dry_run: args.dry_run,
         no_uninstall: args.no_uninstall,
     };
-    let rules = parse_rules(fs::read_to_string(args.file).expect("Failed to read input file"));
+
+    let rules_file =
+        get_rules_file(&args).or_exit_("Must specify -f or have a ~/.sdk-rules.yaml file");
+    let rules = parse_rules(fs::read_to_string(rules_file).or_exit_("Failed to read rules file"));
+
     for (name, candidate) in rules.expect("Rules file could not be parsed").candidates {
         let installed: HashSet<_> = sdkman
             .installed_versions(name.clone())