Implement notion shim command

crates/notion-core/src/lib.rs

@@ -31,10 +31,11 @@ pub mod monitor;
 mod package_info;
 pub mod path;
 mod plugin;
-pub mod shell;
 pub mod project;
 pub mod serial;
 pub mod session;
+pub mod shell;
+pub mod shim;
 pub mod style;
 pub mod tool;
 

crates/notion-core/src/path/unix.rs

@@ -1,8 +1,9 @@
 //! Provides functions for determining the paths of files and directories
 //! in a standard Notion layout in Unix-based operating systems.
 
-use std::env;
+use std::{env, io};
 use std::path::PathBuf;
+use std::os::unix;
 
 use notion_fail::{Fallible, NotionFail};
 
@@ -157,3 +158,7 @@ pub fn user_config_file() -> Fallible<PathBuf> {
 pub fn user_catalog_file() -> Fallible<PathBuf> {
     Ok(notion_home()?.join("catalog.toml"))
 }
+
+pub fn create_file_symlink(src: PathBuf, dst: PathBuf) -> Result<(), io::Error> {
+    unix::fs::symlink(src, dst)
+}

crates/notion-core/src/path/windows.rs

@@ -2,6 +2,8 @@
 //! in a standard Notion layout in Windows operating systems.
 
 use std::path::PathBuf;
+use std::os::windows;
+use std::io;
 
 use winfolder;
 
@@ -154,3 +156,7 @@ pub fn user_config_file() -> Fallible<PathBuf> {
 pub fn user_catalog_file() -> Fallible<PathBuf> {
     Ok(local_data_root()?.join("catalog.toml"))
 }
+
+pub fn create_file_symlink(src: PathBuf, dst: PathBuf) -> Result<(), io::Error> {
+    windows::fs::symlink_file(src, dst)
+}

crates/notion-core/src/session.rs

@@ -30,6 +30,7 @@ pub enum ActivityKind {
     Help,
     Version,
     Binary,
+    Shim,
 }
 
 impl Display for ActivityKind {
@@ -48,6 +49,7 @@ impl Display for ActivityKind {
             &ActivityKind::Help => "help",
             &ActivityKind::Version => "version",
             &ActivityKind::Binary => "binary",
+            &ActivityKind::Shim => "shim",
         };
         f.write_str(s)
     }

crates/notion-core/src/shell/bash.rs

@@ -3,7 +3,7 @@ use std::path::{Path, PathBuf};
 use super::{Postscript, Shell};
 
 pub(crate) struct Bash {
-    pub(crate) postscript_path: PathBuf
+    pub(crate) postscript_path: PathBuf,
 }
 
 impl Shell for Bash {
@@ -17,9 +17,14 @@ impl Shell for Bash {
                 // ISSUE(#99): proper escaping
                 format!("export PATH='{}'\n", s)
             }
-            &Postscript::ToolVersion { ref tool, ref version } => {
-                format!("export NOTION_{}_VERSION={}\n", tool.to_ascii_uppercase(), version)
-            }
+            &Postscript::ToolVersion {
+                ref tool,
+                ref version,
+            } => format!(
+                "export NOTION_{}_VERSION={}\n",
+                tool.to_ascii_uppercase(),
+                version
+            ),
         }
     }
 }

crates/notion-core/src/shell/mod.rs

@@ -5,7 +5,7 @@ use std::str::FromStr;
 
 use semver::Version;
 
-use notion_fail::{NotionError, NotionFail, Fallible, ResultExt};
+use notion_fail::{Fallible, NotionError, NotionFail, ResultExt};
 
 use env;
 
@@ -15,7 +15,7 @@ pub(crate) use self::bash::Bash;
 
 pub enum Postscript {
     Path(String),
-    ToolVersion { tool: String, version: Version }
+    ToolVersion { tool: String, version: Version },
 }
 
 /// Thrown when the postscript file was not specified in the Notion environment.
@@ -39,7 +39,8 @@ pub trait Shell {
 
     fn save_postscript(&self, postscript: &Postscript) -> Fallible<()> {
         let mut file = File::create(self.postscript_path()).unknown()?;
-        file.write_all(self.compile_postscript(postscript).as_bytes()).unknown()?;
+        file.write_all(self.compile_postscript(postscript).as_bytes())
+            .unknown()?;
         Ok(())
     }
 }
@@ -64,7 +65,9 @@ impl CurrentShell {
     pub fn detect() -> Fallible<Self> {
         match env::shell_name() {
             Some(name) => Ok(name.parse()?),
-            None => { throw!(UnspecifiedShellError); }
+            None => {
+                throw!(UnspecifiedShellError);
+            }
         }
     }
 }
@@ -81,12 +84,11 @@ impl Shell for CurrentShell {
     }
 }
 
-
 /// Thrown when the shell name specified in the Notion environment is not supported.
 #[derive(Fail, Debug)]
 #[fail(display = "Unrecognized command shell name: {}", name)]
 struct UnrecognizedShellError {
-    name: String
+    name: String,
 }
 
 impl NotionFail for UnrecognizedShellError {
@@ -106,7 +108,11 @@ impl FromStr for CurrentShell {
 
         Ok(CurrentShell(match src {
             "bash" => Box::new(Bash { postscript_path }),
-            _ => { throw!(UnrecognizedShellError { name: src.to_string() }); }
+            _ => {
+                throw!(UnrecognizedShellError {
+                    name: src.to_string()
+                });
+            }
         }))
     }
 }

crates/notion-core/src/shim.rs

@@ -0,0 +1,80 @@
+//! Provides utilities for modifying shims for 3rd-party executables
+
+use std::{fs, io};
+
+use notion_fail::{FailExt, Fallible, NotionFail};
+use path;
+
+#[derive(Fail, Debug)]
+#[fail(display = "{}", error)]
+pub(crate) struct SymlinkError {
+    error: String,
+}
+
+impl NotionFail for SymlinkError {
+    fn is_user_friendly(&self) -> bool {
+        true
+    }
+    fn exit_code(&self) -> i32 {
+        4
+    }
+}
+
+impl SymlinkError {
+    pub(crate) fn from_io_error(error: &io::Error) -> Self {
+        if let Some(inner_err) = error.get_ref() {
+            SymlinkError {
+                error: inner_err.to_string(),
+            }
+        } else {
+            SymlinkError {
+                error: error.to_string(),
+            }
+        }
+    }
+}
+
+fn is_3p_shim(name: &str) -> bool {
+    match name {
+        "node" | "yarn" | "npm" | "npx" => false,
+        _ => true,
+    }
+}
+
+pub fn create(shim_name: &str) -> Fallible<()> {
+    let launchbin = path::launchbin_file()?;
+    let shim = path::shim_file(shim_name)?;
+    match path::create_file_symlink(launchbin, shim) {
+        Ok(_) => Ok(()),
+        Err(err) => {
+            if err.kind() == io::ErrorKind::AlreadyExists {
+                throw!(SymlinkError {
+                    error: format!("shim `{}` already exists", shim_name),
+                });
+            } else {
+                throw!(err.with_context(SymlinkError::from_io_error));
+            }
+        }
+    }
+}
+
+pub fn delete(shim_name: &str) -> Fallible<()> {
+    if !is_3p_shim(shim_name) {
+        throw!(SymlinkError {
+            error: format!("cannot delete `{}`, not a 3rd-party executable", shim_name),
+        });
+    }
+    let shim = path::shim_file(shim_name)?;
+    match fs::remove_file(shim) {
+        Ok(_) => Ok(()),
+        Err(err) => {
+            if err.kind() == io::ErrorKind::NotFound {
+                throw!(SymlinkError {
+                    error: format!("shim `{}` does not exist", shim_name),
+                });
+            } else {
+                throw!(err.with_context(SymlinkError::from_io_error));
+            }
+        }
+    }
+}

src/command/deactivate.rs

@@ -1,6 +1,6 @@
 use notion_core::env;
-use notion_core::shell::{CurrentShell, Postscript, Shell};
 use notion_core::session::{ActivityKind, Session};
+use notion_core::shell::{CurrentShell, Postscript, Shell};
 use notion_fail::Fallible;
 
 use Notion;
@@ -47,7 +47,7 @@ Options:
 
                 let postscript = match env::path_for_system_node().into_string() {
                     Ok(path) => Postscript::Path(path),
-                    Err(_) => unimplemented!()
+                    Err(_) => unimplemented!(),
                 };
 
                 shell.save_postscript(&postscript)?;

src/command/help.rs

@@ -1,7 +1,8 @@
 use notion_core::session::{ActivityKind, Session};
 use notion_fail::Fallible;
 
-use command::{Command, CommandName, Config, Current, Deactivate, Default, Install, Uninstall, Use, Version};
+use command::{Command, CommandName, Config, Current, Deactivate, Default, Install, Shim,
+              Uninstall, Use, Version};
 use {CliParseError, Notion};
 
 #[derive(Debug, Deserialize)]
@@ -63,6 +64,7 @@ Options:
                 Help::Command(CommandName::Version) => Version::USAGE,
                 Help::Command(CommandName::Install) => Install::USAGE,
                 Help::Command(CommandName::Uninstall) => Uninstall::USAGE,
+                Help::Command(CommandName::Shim) => Shim::USAGE,
             }
         );
         session.add_event_end(ActivityKind::Help, 0);

src/command/mod.rs

@@ -4,6 +4,7 @@ mod deactivate;
 mod default;
 mod help;
 mod install;
+mod shim;
 mod uninstall;
 mod use_;
 mod version;
@@ -14,6 +15,7 @@ pub(crate) use self::deactivate::Deactivate;
 pub(crate) use self::default::Default;
 pub(crate) use self::help::Help;
 pub(crate) use self::install::Install;
+pub(crate) use self::shim::Shim;
 pub(crate) use self::uninstall::Uninstall;
 pub(crate) use self::use_::Use;
 pub(crate) use self::version::Version;
@@ -39,6 +41,7 @@ pub(crate) enum CommandName {
     Current,
     Deactivate,
     Default,
+    Shim,
     Help,
     Version,
 }
@@ -56,6 +59,7 @@ impl Display for CommandName {
                 CommandName::Deactivate => "deactivate",
                 CommandName::Default => "default",
                 CommandName::Current => "current",
+                CommandName::Shim => "shim",
                 CommandName::Help => "help",
                 CommandName::Version => "version",
             }
@@ -75,6 +79,7 @@ impl FromStr for CommandName {
             "current" => CommandName::Current,
             "deactivate" => CommandName::Deactivate,
             "default" => CommandName::Default,
+            "shim" => CommandName::Shim,
             "help" => CommandName::Help,
             "version" => CommandName::Version,
             _ => {