From 5f2d3a269f0f50d261ed6364ae42efd5491504f7 Mon Sep 17 00:00:00 2001
From: Gal Schlezinger <gal@spitfire.co.il>
Date: Thu, 1 Apr 2021 15:49:12 +0300
Subject: [PATCH] Create version symlinks in a nested directory (#422)

---
 src/commands/env.rs | 18 ++++++++++--------
 src/config.rs       | 26 ++++++++++++++++----------
 src/main.rs         |  1 +
 src/path_ext.rs     | 12 ++++++++++++
 4 files changed, 39 insertions(+), 18 deletions(-)
 create mode 100644 src/path_ext.rs

diff --git a/src/commands/env.rs b/src/commands/env.rs
index 353619b..5173646 100644
--- a/src/commands/env.rs
+++ b/src/commands/env.rs
@@ -2,6 +2,7 @@ use super::command::Command;
 use crate::config::FnmConfig;
 use crate::fs::symlink_dir;
 use crate::outln;
+use crate::path_ext::PathExt;
 use crate::shell::{infer_shell, Shell, AVAILABLE_SHELLS};
 use colored::Colorize;
 use snafu::{OptionExt, Snafu};
@@ -22,21 +23,22 @@ pub struct Env {
     use_on_cd: bool,
 }
 
-fn generate_symlink_path(root: &std::path::Path) -> std::path::PathBuf {
-    let temp_dir_name = format!(
-        "fnm_multishell_{}_{}",
+fn generate_symlink_path() -> String {
+    format!(
+        "{}_{}",
         std::process::id(),
         chrono::Utc::now().timestamp_millis(),
-    );
-    root.join(temp_dir_name)
+    )
 }
 
 fn make_symlink(config: &FnmConfig) -> std::path::PathBuf {
-    let system_temp_dir = std::env::temp_dir();
-    let mut temp_dir = generate_symlink_path(&system_temp_dir);
+    let base_dir = std::env::temp_dir()
+        .join("fnm_multishells")
+        .ensure_exists_silently();
+    let mut temp_dir = base_dir.join(generate_symlink_path());
 
     while temp_dir.exists() {
-        temp_dir = generate_symlink_path(&system_temp_dir);
+        temp_dir = base_dir.join(generate_symlink_path());
     }
 
     symlink_dir(config.default_version_dir(), &temp_dir).expect("Can't create symlink!");
diff --git a/src/config.rs b/src/config.rs
index 3f261db..843b00c 100644
--- a/src/config.rs
+++ b/src/config.rs
@@ -1,5 +1,6 @@
 use crate::arch;
 use crate::log_level::LogLevel;
+use crate::path_ext::PathExt;
 use dirs::home_dir;
 use structopt::StructOpt;
 
@@ -64,14 +65,16 @@ impl FnmConfig {
     }
 
     pub fn base_dir_with_default(&self) -> std::path::PathBuf {
-        ensure_exists_silently(
-            (self.base_dir.clone())
-                .unwrap_or_else(|| home_dir().expect("Can't get home directory").join(".fnm")),
-        )
+        self.base_dir
+            .clone()
+            .unwrap_or_else(|| home_dir().expect("Can't get home directory").join(".fnm"))
+            .ensure_exists_silently()
     }
 
     pub fn installations_dir(&self) -> std::path::PathBuf {
-        ensure_exists_silently(self.base_dir_with_default().join("node-versions"))
+        self.base_dir_with_default()
+            .join("node-versions")
+            .ensure_exists_silently()
     }
 
     pub fn default_version_dir(&self) -> std::path::PathBuf {
@@ -79,7 +82,9 @@ impl FnmConfig {
     }
 
     pub fn aliases_dir(&self) -> std::path::PathBuf {
-        ensure_exists_silently(self.base_dir_with_default().join("aliases"))
+        self.base_dir_with_default()
+            .join("aliases")
+            .ensure_exists_silently()
     }
 
     #[cfg(test)]
@@ -87,9 +92,10 @@ impl FnmConfig {
         self.base_dir = base_dir;
         self
     }
-}
 
-fn ensure_exists_silently<T: AsRef<std::path::Path>>(path: T) -> T {
-    std::fs::create_dir_all(path.as_ref()).ok();
-    path
+    pub fn multishell_base_dir(&self) -> std::path::PathBuf {
+        std::env::temp_dir()
+            .join("fnm_multishell")
+            .ensure_exists_silently()
+    }
 }
diff --git a/src/main.rs b/src/main.rs
index c85ac2e..78470bb 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -11,6 +11,7 @@ mod downloader;
 mod fs;
 mod installed_versions;
 mod lts;
+mod path_ext;
 mod remote_node_index;
 mod shell;
 mod system_info;
diff --git a/src/path_ext.rs b/src/path_ext.rs
new file mode 100644
index 0000000..7a5fea2
--- /dev/null
+++ b/src/path_ext.rs
@@ -0,0 +1,12 @@
+pub trait PathExt {
+    fn ensure_exists_silently(self) -> Self;
+}
+
+impl<T: AsRef<std::path::Path>> PathExt for T {
+    /// Ensures a path is existing by creating it recursively
+    /// if it is missing. No error is emitted if the creation has failed.
+    fn ensure_exists_silently(self) -> Self {
+        std::fs::create_dir_all(self.as_ref()).ok();
+        self
+    }
+}