feat: better error message when installing Elixir without Erlang

Also adds test installing elixir without erlang

shelltests/installs.test

@@ -34,4 +34,9 @@ target/debug/beamup install gleam v1.4.1
 
 # force an install of the same version
 target/debug/beamup install -f true gleam v1.4.1
->>>=0
+>>>=0
+
+# test attempt to install elixir without erlang
+target/debug/beamup install elixir latest
+>>>2 /Error: No default Erlang installation found. Install an Erlang version, like `beamup install erlang latest` or set a default with `beamup default erlang <ID>` first./
+>>>=1

src/cmd/install.rs

@@ -20,8 +20,6 @@ pub fn run(
     _repo: &Option<String>,
     force: &Option<bool>,
 ) -> Result<String, Report> {
-    let release_dir = config::language_release_dir(language, id, force)?;
-
     let out_dir = TempDir::new(github_repo.repo.as_str())?;
     let file = download_asset(language, out_dir.path(), github_repo, release)?;
     debug!("file {:?} downloaded", file);
@@ -32,6 +30,8 @@ pub fn run(
         )
     })?;
 
+    let release_dir = config::language_release_dir(language, id, force)?;
+
     // TODO: better ways to check the type than the extension
     let ext = file.extension().map_or("", |e| e.to_str().unwrap_or(""));
     match ext {

src/config.rs

@@ -51,9 +51,9 @@ fn get_language_config(language: &languages::Language, config: &Config) -> Langu
 
 fn get_default_id(lc: &Option<LanguageConfig>) -> Result<String> {
     match lc {
-        None => Err(eyre!("No default found for {:?}", lc)),
+        None => Err(eyre!("No default found for language {:?}", lc)),
         Some(lc) => match &lc.default {
-            None => Err(eyre!("No default found for language")),
+            None => Err(eyre!("No default found for language {:?}", lc)),
             Some(default) => {
                 debug!("Found default {:?}", default);
                 Ok(default.to_string())
@@ -89,7 +89,10 @@ fn get_local_id(language_str: String, local_config: &Option<toml::Table>) -> Opt
 }
 
 pub fn get_otp_major_vsn() -> Result<String> {
-    let dir = install_to_use("erl")?;
+    let dir = match install_to_use("erl") {
+        Ok(dir) => Ok(dir),
+        Err(_) => Err(eyre!("No default Erlang installation found. Install an Erlang version, like `beamup install erlang latest` or set a default with `beamup default erlang <ID>` first.")),
+    }?;
     let releases_dir = Path::new(&dir).join("lib").join("erlang").join("releases");
     let mut otps = std::fs::read_dir(&releases_dir)?;
     let binding = otps

src/github.rs

@@ -154,6 +154,8 @@ pub fn download_asset(
     GithubRepo { org, repo }: &GithubRepo,
     tag: &str,
 ) -> Result<PathBuf, Report> {
+    let asset_name = asset_name(language, tag)?;
+
     let rt = setup_tokio();
 
     let release_result = if tag == "latest" {
@@ -186,8 +188,6 @@ pub fn download_asset(
         }
     };
 
-    let asset_name = asset_name(language, tag)?;
-
     match assets.iter().find(|&asset| *asset.name == asset_name) {
         Some(asset) => {
             let file = out_dir.join(asset_name);