feat: Add starship preset command (#4112)

* Add starship preset command

* Use ValueEnum for preset command

* Generate ValueEnum struct in build.rs

* Use absolute paths and refactor codegen

* Use dunce to canonicalize path

* Use raw string literal in include_bytes!

* Use .cloned()

* Apply fixes

* Fix path escaping

* Removed error message if stdout is unavailable

Co-authored-by: David Knaack <davidkna@users.noreply.github.com>

Co-authored-by: David Knaack <davidkna@users.noreply.github.com>

Cargo.toml

@@ -110,6 +110,7 @@ nix = { version = "0.24.2", default-features = false, features = ["feature", "fs
 
 [build-dependencies]
 shadow-rs = "0.16.1"
+dunce = "1.0.2"
 
 [target.'cfg(windows)'.build-dependencies]
 winres = "0.1.12"

build.rs

@@ -1,7 +1,11 @@
-use std::error::Error;
+use std::fs::{self, File};
+use std::io::Write;
 
-fn main() -> Result<(), Box<dyn Error>> {
+use shadow_rs::SdResult;
+
+fn main() -> SdResult<()> {
     shadow_rs::new().map_err(|err| err.to_string())?;
+    shadow_rs::new_hook(gen_presets_hook)?;
 
     #[cfg(windows)]
     {
@@ -13,3 +17,55 @@ fn main() -> Result<(), Box<dyn Error>> {
 
     Ok(())
 }
+
+fn gen_presets_hook(mut file: &File) -> SdResult<()> {
+    println!("cargo:rerun-if-changed=docs/.vuepress/public/presets/toml");
+    let paths = fs::read_dir("docs/.vuepress/public/presets/toml")?;
+
+    let mut presets = String::new();
+    let mut match_arms = String::new();
+    for path in paths {
+        let unwrapped = path?;
+        let file_name = unwrapped.file_name();
+        let full_path = dunce::canonicalize(unwrapped.path())?;
+        let full_path = full_path.to_str().expect("failed to convert to string");
+        let name = file_name
+            .to_str()
+            .and_then(|v| v.strip_suffix(".toml"))
+            .expect("Failed to process filename");
+        presets.push_str(format!("print::Preset(\"{}\"),\n", name).as_str());
+        match_arms.push_str(
+            format!(
+                r#"
+"{name}" => {{
+        let mut stdout = io::stdout().lock();
+        let _ = stdout.write_all(include_bytes!(r"{full_path}"));
+}}
+"#
+            )
+            .as_str(),
+        );
+    }
+
+    writeln!(
+        file,
+        r#"
+use std::io::{{self, Write}};
+use crate::print;
+
+pub fn get_preset_list<'a>() -> &'a [print::Preset] {{
+    &[
+        {presets}
+    ]
+}}
+
+pub fn print_preset_content(name: &str) {{
+    match name {{
+    {match_arms}
+    _ => {{}}
+    }}
+}}
+"#
+    )?;
+    Ok(())
+}

docs/presets/bracketed-segments.md

@@ -9,6 +9,10 @@ in brackets instead of using the default Starship wording ("via", "on", etc.).
 
 ### Configuration
 
+```sh
+starship preset bracketed-segments > ~/.config/starship.toml
+```
+
 [Click to download TOML](/presets/toml/bracketed-segments.toml)
 
 <<< @/.vuepress/public/presets/toml/bracketed-segments.toml

docs/presets/nerd-font.md

@@ -12,6 +12,10 @@ This preset changes the symbols for each module to use Nerd Font symbols.
 
 ### Configuration
 
+```sh
+starship preset nerd-font-symbols > ~/.config/starship.toml
+```
+
 [Click to download TOML](/presets/toml/nerd-font-symbols.toml)
 
 <<< @/.vuepress/public/presets/toml/nerd-font-symbols.toml

docs/presets/no-runtimes.md

@@ -8,6 +8,10 @@ This preset hides the version of language runtimes. If you work in containers or
 
 ### Configuration
 
+```sh
+starship preset no-runtime-versions > ~/.config/starship.toml
+```
+
 [Click to download TOML](/presets/toml/no-runtime-versions.toml)
 
 <<< @/.vuepress/public/presets/toml/no-runtime-versions.toml

docs/presets/pastel-powerline.md

@@ -13,6 +13,10 @@ It also shows how path substitution works in starship.
 
 ### Configuration
 
+```sh
+starship preset pastel-powerline > ~/.config/starship.toml
+```
+
 [Click to download TOML](/presets/toml/pastel-powerline.toml)
 
 <<< @/.vuepress/public/presets/toml/pastel-powerline.toml

docs/presets/plain-text.md

@@ -9,6 +9,10 @@ don't have access to Unicode.
 
 ### Configuration
 
+```sh
+starship preset plain-text-symbols > ~/.config/starship.toml
+```
+
 [Click to download TOML](/presets/toml/plain-text-symbols.toml)
 
 <<< @/.vuepress/public/presets/toml/plain-text-symbols.toml

docs/presets/pure-preset.md

@@ -8,6 +8,10 @@ This preset emulates the look and behavior of [Pure](https://github.com/sindreso
 
 ### Configuration
 
+```sh
+starship preset pure-preset > ~/.config/starship.toml
+```
+
 [Click to download TOML](/presets/toml/pure-preset.toml)
 
 <<< @/.vuepress/public/presets/toml/pure-preset.toml

src/main.rs

@@ -63,6 +63,15 @@ enum Commands {
         #[clap(flatten)]
         properties: Properties,
     },
+    /// Prints a preset config
+    Preset {
+        /// The name of preset to be printed
+        #[clap(required_unless_present("list"), value_enum)]
+        name: Option<print::Preset>,
+        /// List out all preset names
+        #[clap(short, long)]
+        list: bool,
+    },
     /// Prints the computed starship configuration
     PrintConfig {
         /// Print the default instead of the computed config
@@ -182,6 +191,7 @@ fn main() {
                 print::module(&module_name, properties);
             }
         }
+        Commands::Preset { name, list } => print::preset_command(name, list),
         Commands::Config { name, value } => {
             if let Some(name) = name {
                 if let Some(value) = value {

src/print.rs

@@ -1,4 +1,5 @@
 use ansi_term::ANSIStrings;
+use clap::{PossibleValue, ValueEnum};
 use rayon::prelude::*;
 use std::collections::BTreeSet;
 use std::fmt::{self, Debug, Write as FmtWrite};
@@ -15,6 +16,7 @@ use crate::module::Module;
 use crate::module::ALL_MODULES;
 use crate::modules;
 use crate::segment::Segment;
+use crate::shadow;
 
 pub struct Grapheme<'a>(pub &'a str);
 
@@ -450,6 +452,35 @@ pub fn print_schema() {
     println!("{}", serde_json::to_string_pretty(&schema).unwrap());
 }
 
+#[derive(Clone, Debug)]
+pub struct Preset(pub &'static str);
+
+impl ValueEnum for Preset {
+    fn value_variants<'a>() -> &'a [Self] {
+        shadow::get_preset_list()
+    }
+
+    fn to_possible_value<'a>(&self) -> Option<clap::PossibleValue<'a>> {
+        Some(PossibleValue::new(self.0))
+    }
+}
+
+pub fn preset_command(name: Option<Preset>, list: bool) {
+    if list {
+        println!("{}", preset_list());
+        return;
+    }
+    let variant = name.expect("name argument must be specified");
+    shadow::print_preset_content(variant.0);
+}
+
+fn preset_list() -> String {
+    Preset::value_variants()
+        .iter()
+        .map(|v| format!("{}\n", v.0))
+        .collect()
+}
+
 #[cfg(test)]
 mod test {
     use super::*;
@@ -490,6 +521,19 @@ mod test {
         assert_eq!(expected, actual);
     }
 
+    #[test]
+    fn preset_list_returns_one_or_more_items() {
+        assert!(preset_list().trim().split('\n').count() > 0);
+    }
+
+    #[test]
+    fn preset_command_does_not_panic_on_correct_inputs() {
+        preset_command(None, true);
+        Preset::value_variants()
+            .iter()
+            .for_each(|v| preset_command(Some(v.clone()), false));
+    }
+
     #[test]
     #[cfg(feature = "config-schema")]
     fn print_schema_does_not_panic() {