refactor(init): cleanup init stub (#2548)

* refactor(init): cleanup init stub

* refactor(init): use iex PowerShell alias

* fix(init): prevent bash scope pollution

* refactor(init): update PowerShell snippet

src/init/mod.rs

@@ -88,8 +88,8 @@ pub fn init_stub(shell_name: &str) -> io::Result<()> {
 
     let starship = StarshipPath::init()?;
 
-    let setup_stub = match shell_basename {
+    match shell_basename {
-        "bash" => {
+        "bash" => print!(
             /*
              * The standard bash bootstrap is:
              *      `source <(starship init bash --print-full-init)`
@@ -121,68 +121,44 @@ pub fn init_stub(shell_name: &str) -> io::Result<()> {
              * https://github.com/starship/starship/pull/241
              * https://github.com/starship/starship/pull/278
              */
-            let script = {
+            r#"
-                format!(
+            __main() {{
-                    r#"if [ "${{BASH_VERSINFO[0]}}" -gt 4 ] || ([ "${{BASH_VERSINFO[0]}}" -eq 4 ] && [ "${{BASH_VERSINFO[1]}}" -ge 1 ])
+                local major="${{BASH_VERSINFO[0]}}"
-then
+                local minor="${{BASH_VERSINFO[1]}}"
+
+                if ((major > 4)) || {{ ((major == 4)) && ((minor >= 1)); }}; then
                     source <("{0}" init bash --print-full-init)
                 else
                     source /dev/stdin <<<"$("{0}" init bash --print-full-init)"
-fi"#,
+                fi
+            }}
+            __main
+            unset -f __main
+            "#,
             starship.sprint_posix()?
-                )
+        ),
-            };
+        "zsh" => print!(
-
+            r#"source <("{}" init zsh --print-full-init)"#,
-            Some(script)
-        }
-        "zsh" => {
-            let script = format!(
-                "source <(\"{}\" init zsh --print-full-init)",
             starship.sprint_posix()?
-            );
+        ),
-            Some(script)
+        "fish" => print!(
-        }
-        "fish" => {
             // Fish does process substitution with pipes and psub instead of bash syntax
-            let script = format!(
+            r#"source ("{}" init fish --print-full-init | psub)"#,
-                "source (\"{}\" init fish --print-full-init | psub)",
             starship.sprint_posix()?
-            );
+        ),
-            Some(script)
+        "powershell" => print!(
-        }
+            r#"Invoke-Expression (& "{}" init powershell --print-full-init | Out-String)"#,
-        "powershell" => {
-            // Explanation of syntax:
-            // &: Explicitly tells powershell to execute path with starship executable.
-            //
-            // @: multi-line stdout is returned as an array, but a single line or no lines
-            //    are returned as-is. @ ensures it's always an array.
-            //
-            // -join "`n": Joins the stdout array together as a string with newlines.
-            //             Powershell escapes with ` instead of \ thus `n translates to a newline.
-            let script = format!(
-                "Invoke-Expression (@(&\"{}\" init powershell --print-full-init) -join \"`n\")",
             starship.sprint()?
-            );
+        ),
-            Some(script)
+        "ion" => print!("eval $({} init ion --print-full-init)", starship.sprint()?),
-        }
+        "elvish" => print!(
-        "ion" => {
+            r#"eval ("{}" init elvish --print-full-init | slurp)"#,
-            let script = format!("eval $({} init ion --print-full-init)", starship.sprint()?);
-            Some(script)
-        }
-        "elvish" => {
-            let script = format!(
-                "eval (\"{}\" init elvish --print-full-init | slurp)",
             starship.sprint_posix()?
-            );
+        ),
-            Some(script)
+        "tcsh" => print!(
-        }
+            r#"eval `("{}" init tcsh --print-full-init)`"#,
-        "tcsh" => {
-            let script = format!(
-                r#"eval "`("{}" init tcsh --print-full-init)`""#,
             starship.sprint_posix()?
-            );
+        ),
-            Some(script)
-        }
         _ => {
             let quoted_arg = shell_words::quote(shell_basename);
             println!(
@@ -199,13 +175,9 @@ fi"#,
                  Please open an issue in the starship repo if you would like to \
                  see support for %s:\\nhttps://github.com/starship/starship/issues/new\\n\\n\" {0} {0}",
                 quoted_arg
-            );
+            )
-            None
         }
     };
-    if let Some(script) = setup_stub {
-        print!("{}", script);
-    };
     Ok(())
 }