Support Apple M1 by installing Rosetta Node builds (#417)

README.md

@@ -168,15 +168,25 @@ FOR /f "tokens=*" %i IN ('fnm env --use-on-cd') DO CALL %i
 ### Global Options
 
 ```sh
-fnm [--shell=fish|bash|zsh] [--node-dist-mirror=URI] [--fnm-dir=DIR] [--log-level=quiet|error|info] <command>
+fnm [--shell=fish|bash|zsh] [--node-dist-mirror=URI] [--fnm-dir=DIR] [--log-level=quiet|error|info] [--arch=ARCH] <command>
 ```
 
-- Providing `--shell=fish` will output the Fish-compliant version. Omitting it and `fnm` will try to infer the current shell based on the process tree
+- Providing `--shell=fish` will output the Fish-compliant version. Omit it and `fnm` will try to infer the current shell based on the process tree
 - Providing `--node-dist-mirror="https://npm.taobao.org/dist"` will use the Chinese mirror of Node.js
 - Providing `--fnm-dir="/tmp/fnm"` will install and use versions in `/tmp/fnm` directory
+- Providing `--arch=x64`  will install Node binaries with `x86-64` architecture. Omit it and `fnm` will default to your computer's architecture.
 
 You can always use `fnm --help` to read the docs:
 
+#### Apple Silicon
+Until [upstream support for darwin-arm64](https://github.com/nodejs/node/issues/37309) is complete, `fnm` defaults to installing the `darwin-x64` architecture for your selected version to be run with Rosetta 2.
+
+Enable Rosetta 2 via terminal command:
+```sh
+softwareupdate --install-rosetta
+```
+The `--arch` option overrides this default.
+
 ### `fnm install [VERSION]`
 
 Installs `[VERSION]`. If no version provided, it will install the version specified in the `.node-version` or `.nvmrc` files located in the current working directory.

src/arch.rs

@@ -0,0 +1,94 @@
+#[derive(Clone, Debug)]
+pub enum Arch {
+    X86,
+    X64,
+    Arm64,
+    Armv7l,
+    Ppc64le,
+    Ppc64,
+    S390x,
+}
+
+#[cfg(unix)]
+/// Get a sane default architecture for the platform.
+pub fn default_str() -> &'static str {
+    use crate::system_info::{platform_arch, platform_name};
+
+    // TODO: Handle (arch, name, version) when Node v15+ supports darwin-arm64
+    match (platform_name(), platform_arch()) {
+        ("darwin", "arm64") => "x64",
+        (_, arch) => arch,
+    }
+}
+
+#[cfg(windows)]
+/// Get a sane default architecture for the platform.
+pub fn default_str() -> &'static str {
+    return crate::system_info::platform_arch();
+}
+
+impl Default for Arch {
+    fn default() -> Arch {
+        match default_str().parse() {
+            Ok(arch) => arch,
+            Err(e) => panic!("{}", e.details),
+        }
+    }
+}
+
+impl std::str::FromStr for Arch {
+    type Err = ArchError;
+    fn from_str(s: &str) -> Result<Arch, Self::Err> {
+        match s {
+            "x86" => Ok(Arch::X86),
+            "x64" => Ok(Arch::X64),
+            "arm64" => Ok(Arch::Arm64),
+            "armv7l" => Ok(Arch::Armv7l),
+            "ppc64le" => Ok(Arch::Ppc64le),
+            "ppc64" => Ok(Arch::Ppc64),
+            "s390x" => Ok(Arch::S390x),
+            unknown => Err(ArchError::new(&format!("Unknown Arch: {}", unknown))),
+        }
+    }
+}
+
+impl std::fmt::Display for Arch {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        let arch_str = match self {
+            Arch::X86 => String::from("x86"),
+            Arch::X64 => String::from("x64"),
+            Arch::Arm64 => String::from("arm64"),
+            Arch::Armv7l => String::from("armv7l"),
+            Arch::Ppc64le => String::from("ppc64le"),
+            Arch::Ppc64 => String::from("ppc64"),
+            Arch::S390x => String::from("s390x"),
+        };
+
+        write!(f, "{}", arch_str)
+    }
+}
+
+#[derive(Debug)]
+pub struct ArchError {
+    details: String,
+}
+
+impl ArchError {
+    fn new(msg: &str) -> ArchError {
+        ArchError {
+            details: msg.to_string(),
+        }
+    }
+}
+
+impl std::fmt::Display for ArchError {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        write!(f, "{}", self.details)
+    }
+}
+
+impl std::error::Error for ArchError {
+    fn description(&self) -> &str {
+        &self.details
+    }
+}

src/commands/install.rs

@@ -46,6 +46,7 @@ impl super::command::Command for Install {
 
     fn apply(self, config: &FnmConfig) -> Result<(), Self::Error> {
         let current_dir = std::env::current_dir().unwrap();
+
         let current_version = self
             .version()?
             .or_else(|| get_user_version_for_directory(current_dir))
@@ -89,12 +90,14 @@ impl super::command::Command for Install {
                     .clone()
             }
         };
+
         let version_str = format!("Node {}", &version);
         outln!(config#Info, "Installing {}", version_str.cyan());
         match install_node_dist(
             &version,
             &config.node_dist_mirror,
             config.installations_dir(),
+            &config.arch,
         ) {
             Err(err @ DownloaderError::VersionAlreadyInstalled { .. }) => {
                 outln!(config#Error, "{} {}", "warning:".bold().yellow(), err);
@@ -123,7 +126,7 @@ impl super::command::Command for Install {
 
 #[derive(Debug, Snafu)]
 pub enum Error {
-    #[snafu(display("Can't download the requested version: {}", source))]
+    #[snafu(display("Can't download the requested binary: {}", source))]
     DownloadError {
         source: DownloaderError,
     },

src/config.rs

@@ -1,3 +1,4 @@
+use crate::arch;
 use crate::log_level::LogLevel;
 use dirs::home_dir;
 use structopt::StructOpt;
@@ -31,6 +32,11 @@ pub struct FnmConfig {
     /// The log level of fnm commands
     #[structopt(long, env = "FNM_LOGLEVEL", default_value = "info", global = true)]
     log_level: LogLevel,
+
+    /// Override the architecture of the installed Node binary.
+    /// Defaults to arch of fnm binary.
+    #[structopt(long, env = "FNM_ARCH", default_value, global = true)]
+    pub arch: arch::Arch,
 }
 
 impl Default for FnmConfig {
@@ -40,6 +46,7 @@ impl Default for FnmConfig {
             base_dir: None,
             multishell_path: None,
             log_level: LogLevel::Info,
+            arch: Default::default(),
         }
     }
 }

src/downloader.rs

@@ -1,3 +1,4 @@
+use crate::arch::Arch;
 use crate::archive;
 use crate::archive::{Error as ExtractError, Extract};
 use crate::directory_portal::DirectoryPortal;
@@ -22,8 +23,15 @@ pub enum Error {
     },
     #[snafu(display("The downloaded archive is empty"))]
     TarIsEmpty,
-    #[snafu(display("Can't find version upstream"))]
+    #[snafu(display(
-    VersionNotFound,
+        "{} for {} not found upstream.\nYou can `fnm ls-remote` to see available versions or try a different `--arch`.",
+        version,
+        arch
+    ))]
+    VersionNotFound {
+        version: Version,
+        arch: Arch,
+    },
     #[snafu(display("Version already installed at {:?}", path))]
     VersionAlreadyInstalled {
         path: PathBuf,
@@ -31,31 +39,30 @@ pub enum Error {
 }
 
 #[cfg(unix)]
-fn filename_for_version(version: &Version) -> String {
+fn filename_for_version(version: &Version, arch: &Arch) -> String {
-    use crate::system_info::{platform_arch, platform_name};
     format!(
         "node-{node_ver}-{platform}-{arch}.tar.xz",
         node_ver = &version,
-        platform = platform_name(),
+        platform = crate::system_info::platform_name(),
-        arch = platform_arch(),
+        arch = arch,
     )
 }
 
 #[cfg(windows)]
-fn filename_for_version(version: &Version) -> String {
+fn filename_for_version(version: &Version, arch: &Arch) -> String {
     format!(
         "node-{node_ver}-win-{arch}.zip",
         node_ver = &version,
-        arch = crate::system_info::platform_arch(),
+        arch = arch,
     )
 }
 
-fn download_url(base_url: &Url, version: &Version) -> Url {
+fn download_url(base_url: &Url, version: &Version, arch: &Arch) -> Url {
     Url::parse(&format!(
         "{}/{}/{}",
         base_url.as_str().trim_end_matches('/'),
         version,
-        filename_for_version(version)
+        filename_for_version(version, arch)
     ))
     .unwrap()
 }
@@ -77,6 +84,7 @@ pub fn install_node_dist<P: AsRef<Path>>(
     version: &Version,
     node_dist_mirror: &Url,
     installations_dir: P,
+    arch: &Arch,
 ) -> Result<(), Error> {
     let installation_dir = PathBuf::from(installations_dir.as_ref()).join(version.v_str());
 
@@ -94,12 +102,15 @@ pub fn install_node_dist<P: AsRef<Path>>(
 
     let portal = DirectoryPortal::new_in(&temp_installations_dir, installation_dir);
 
-    let url = download_url(node_dist_mirror, version);
+    let url = download_url(node_dist_mirror, version, arch);
     debug!("Going to call for {}", &url);
     let response = reqwest::blocking::get(url).context(HttpError)?;
 
     if response.status() == 404 {
-        return Err(Error::VersionNotFound);
+        return Err(Error::VersionNotFound {
+            version: version.clone(),
+            arch: arch.clone(),
+        });
     }
 
     debug!("Extracting response...");
@@ -167,8 +178,10 @@ mod tests {
 
     fn install_in(path: &Path) -> PathBuf {
         let version = Version::parse("12.0.0").unwrap();
+        let arch = Arch::X64;
         let node_dist_mirror = Url::parse("https://nodejs.org/dist/").unwrap();
-        install_node_dist(&version, &node_dist_mirror, &path).expect("Can't install Node 12");
+        install_node_dist(&version, &node_dist_mirror, &path, &arch)
+            .expect("Can't install Node 12");
 
         let mut location_path = path.join(version.v_str()).join("installation");
 

src/main.rs

@@ -1,4 +1,5 @@
 mod alias;
+mod arch;
 mod archive;
 mod choose_version_for_user_input;
 mod cli;