feat: use arm for aarch64-darwin-node@16 platforms (#436)

src/arch.rs

@@ -1,4 +1,6 @@
-#[derive(Clone, Debug)]
+use crate::version::Version;
+
+#[derive(Clone, PartialEq, Eq, Debug)]
 pub enum Arch {
     X86,
     X64,
@@ -10,26 +12,25 @@ pub enum Arch {
 }
 
 #[cfg(unix)]
-/// Get a sane default architecture for the platform.
+/// handle common case: Apple Silicon / Node < 16
-pub fn default_str() -> &'static str {
+pub fn get_safe_arch<'a>(arch: &'a Arch, version: &Version) -> &'a Arch {
     use crate::system_info::{platform_arch, platform_name};
 
-    // TODO: Handle (arch, name, version) when Node v15+ supports darwin-arm64
+    return match (platform_name(), platform_arch(), version) {
-    match (platform_name(), platform_arch()) {
+        ("darwin", "arm64", Version::Semver(v)) if v.major < 16 => &Arch::X64,
-        ("darwin", "arm64") => "x64",
+        _ => &arch,
-        (_, arch) => arch,
+    };
-    }
 }
 
 #[cfg(windows)]
-/// Get a sane default architecture for the platform.
+/// handle common case: Apple Silicon / Node < 16
-pub fn default_str() -> &'static str {
+pub fn get_safe_arch<'a>(arch: &'a Arch, _version: &Version) -> &'a Arch {
-    return crate::system_info::platform_arch();
+    return &arch;
 }
 
 impl Default for Arch {
     fn default() -> Arch {
-        match default_str().parse() {
+        match crate::system_info::platform_arch().parse() {
             Ok(arch) => arch,
             Err(e) => panic!("{}", e.details),
         }

src/commands/install.rs

@@ -1,4 +1,5 @@
 use crate::alias::create_alias;
+use crate::arch::get_safe_arch;
 use crate::config::FnmConfig;
 use crate::downloader::{install_node_dist, Error as DownloaderError};
 use crate::lts::LtsType;
@@ -91,13 +92,17 @@ impl super::command::Command for Install {
             }
         };
 
+        // Automatically swap Apple Silicon to x64 arch for appropriate versions.
+        let safe_arch = get_safe_arch(&config.arch, &version);
+
         let version_str = format!("Node {}", &version);
-        outln!(config#Info, "Installing {}", version_str.cyan());
+        outln!(config#Info, "Installing {} ({})", version_str.cyan(), safe_arch.to_string());
+
         match install_node_dist(
             &version,
             &config.node_dist_mirror,
             config.installations_dir(),
-            &config.arch,
+            safe_arch,
         ) {
             Err(err @ DownloaderError::VersionAlreadyInstalled { .. }) => {
                 outln!(config#Error, "{} {}", "warning:".bold().yellow(), err);