feat(ocaml): Add OCaml module (#1218)

* Add OCaml module

* Update README.md accordingly

* Fix typo

* Add Reason support

Obtain OCaml version using `-vnum` flag.
Extend conditions to match projects using jbuild, esy
or merlin.

* Update README.md

Co-authored-by: Dario Vladovic <d.vladimyr@gmail.com>

docs/config/README.md

@@ -116,6 +116,7 @@ prompt_order = [
     "java",
     "julia",
     "nodejs",
+    "ocaml",
     "php",
     "python",
     "ruby",
@@ -1098,6 +1099,35 @@ package, and shows its current version. The module currently supports `npm`, `ca
 symbol = "🎁 "
 ```
 
+## OCaml
+
+The `ocaml` module shows the currently installed version of OCaml.
+The module will be shown if any of the following conditions are met:
+
+- The current directory contains a file with `.opam` extension or `_opam` directory
+- The current directory contains a `esy.lock` directory
+- The current directory contains a `dune` or `dune-project` file
+- The current directory contains a `jbuild` or `jbuild-ignore` file
+- The current directory contains a `.merlin` file
+- The current directory contains a file with `.ml`, `.mli`, `.re` or `.rei` extension
+
+### Options
+
+| Variable   | Default         | Description                                             |
+| ---------- | --------------- | ------------------------------------------------------- |
+| `symbol`   | `"🐫 "`         | The symbol used before displaying the version of OCaml. |
+| `style`    | `"bold yellow"` | The style for the module.                               |
+| `disabled` | `false`         | Disables the `ocaml` module.                            |
+
+### Example
+
+```toml
+# ~/.config/starship.toml
+
+[ocaml]
+symbol = "🐪 "
+```
+
 ## PHP
 
 The `php` module shows the currently installed version of PHP.

src/configs/mod.rs

@@ -27,6 +27,7 @@ pub mod kubernetes;
 pub mod memory_usage;
 pub mod nix_shell;
 pub mod nodejs;
+pub mod ocaml;
 pub mod package;
 pub mod php;
 pub mod python;

src/configs/ocaml.rs

@@ -0,0 +1,23 @@
+use crate::config::{ModuleConfig, RootModuleConfig, SegmentConfig};
+
+use ansi_term::{Color, Style};
+use starship_module_config_derive::ModuleConfig;
+
+#[derive(Clone, ModuleConfig)]
+pub struct OCamlConfig<'a> {
+    pub symbol: SegmentConfig<'a>,
+    pub version: SegmentConfig<'a>,
+    pub style: Style,
+    pub disabled: bool,
+}
+
+impl<'a> RootModuleConfig<'a> for OCamlConfig<'a> {
+    fn new() -> Self {
+        OCamlConfig {
+            symbol: SegmentConfig::new("🐫 "),
+            version: SegmentConfig::default(),
+            style: Color::Yellow.bold(),
+            disabled: false,
+        }
+    }
+}

src/configs/starship_root.rs

@@ -40,6 +40,7 @@ impl<'a> RootModuleConfig<'a> for StarshipRootConfig<'a> {
                 "java",
                 "julia",
                 "nodejs",
+                "ocaml",
                 "php",
                 "python",
                 "ruby",

src/module.rs

@@ -39,6 +39,7 @@ pub const ALL_MODULES: &[&str] = &[
     "memory_usage",
     "nix_shell",
     "nodejs",
+    "ocaml",
     "package",
     "python",
     "ruby",

src/modules/mod.rs

@@ -28,6 +28,7 @@ mod line_break;
 mod memory_usage;
 mod nix_shell;
 mod nodejs;
+mod ocaml;
 mod package;
 mod php;
 mod python;
@@ -79,6 +80,7 @@ pub fn handle<'a>(module: &str, context: &'a Context) -> Option<Module<'a>> {
         "memory_usage" => memory_usage::module(context),
         "nix_shell" => nix_shell::module(context),
         "nodejs" => nodejs::module(context),
+        "ocaml" => ocaml::module(context),
         "package" => package::module(context),
         "php" => php::module(context),
         "python" => python::module(context),
@@ -127,6 +129,7 @@ pub fn description(module: &str) -> &'static str {
         "memory_usage" => "Current system memory and swap usage",
         "nix_shell" => "The nix-shell environment",
         "nodejs" => "The currently installed version of NodeJS",
+        "ocaml" => "The currently installed version of OCaml",
         "package" => "The package version of the current directory's project",
         "php" => "The currently installed version of PHP",
         "python" => "The currently installed version of Python",

src/modules/ocaml.rs

@@ -0,0 +1,187 @@
+use super::{Context, Module, RootModuleConfig, SegmentConfig};
+
+use crate::configs::ocaml::OCamlConfig;
+use crate::utils;
+
+/// Creates a module with the current OCaml version
+///
+/// Will display the OCaml version if any of the following criteria are met:
+///     - Current directory contains a file with `.opam` extension or `_opam` directory
+///     - Current directory contains a `esy.lock` directory
+///     - Current directory contains a `dune` or `dune-project` file
+///     - Current directory contains a `jbuild` or `jbuild-ignore` file
+///     - Current directory contains a `.merlin` file
+///     - Current directory contains a file with `.ml`, `.mli`, `.re` or `.rei` extension
+pub fn module<'a>(context: &'a Context) -> Option<Module<'a>> {
+    let is_ocaml_project = context
+        .try_begin_scan()?
+        .set_files(&["dune", "dune-project", "jbuild", "jbuild-ignore", ".merlin"])
+        .set_folders(&["_opam", "esy.lock"])
+        .set_extensions(&["opam", "ml", "mli", "re", "rei"])
+        .is_match();
+
+    if !is_ocaml_project {
+        return None;
+    }
+
+    let ocaml_version = utils::exec_cmd("ocaml", &["-vnum"])?.stdout;
+    let formatted_version = format!("v{}", &ocaml_version);
+
+    let mut module = context.new_module("ocaml");
+    let config = OCamlConfig::try_load(module.config);
+    module.set_style(config.style);
+
+    module.create_segment("symbol", &config.symbol);
+    module.create_segment("version", &SegmentConfig::new(&formatted_version));
+
+    Some(module)
+}
+
+#[cfg(test)]
+mod tests {
+    use crate::modules::utils::test::render_module;
+    use ansi_term::Color;
+    use std::fs::{self, File};
+    use std::io;
+
+    #[test]
+    fn folder_without_ocaml_file() -> io::Result<()> {
+        let dir = tempfile::tempdir()?;
+        let actual = render_module("ocaml", dir.path(), None);
+        let expected = None;
+        assert_eq!(expected, actual);
+        dir.close()
+    }
+
+    #[test]
+    fn folder_with_opam_file() -> io::Result<()> {
+        let dir = tempfile::tempdir()?;
+        File::create(dir.path().join("any.opam"))?.sync_all()?;
+
+        let actual = render_module("ocaml", dir.path(), None);
+        let expected = Some(format!("via {} ", Color::Yellow.bold().paint("🐫 v4.10.0")));
+        assert_eq!(expected, actual);
+        dir.close()
+    }
+
+    #[test]
+    fn folder_with_opam_directory() -> io::Result<()> {
+        let dir = tempfile::tempdir()?;
+        fs::create_dir_all(dir.path().join("_opam"))?;
+
+        let actual = render_module("ocaml", dir.path(), None);
+        let expected = Some(format!("via {} ", Color::Yellow.bold().paint("🐫 v4.10.0")));
+        assert_eq!(expected, actual);
+        dir.close()
+    }
+
+    #[test]
+    fn folder_with_esy_lock_directory() -> io::Result<()> {
+        let dir = tempfile::tempdir()?;
+        fs::create_dir_all(dir.path().join("esy.lock"))?;
+
+        let actual = render_module("ocaml", dir.path(), None);
+        let expected = Some(format!("via {} ", Color::Yellow.bold().paint("🐫 v4.10.0")));
+        assert_eq!(expected, actual);
+        dir.close()
+    }
+
+    #[test]
+    fn folder_with_dune() -> io::Result<()> {
+        let dir = tempfile::tempdir()?;
+        File::create(dir.path().join("dune"))?.sync_all()?;
+
+        let actual = render_module("ocaml", dir.path(), None);
+        let expected = Some(format!("via {} ", Color::Yellow.bold().paint("🐫 v4.10.0")));
+        assert_eq!(expected, actual);
+        dir.close()
+    }
+
+    #[test]
+    fn folder_with_dune_project() -> io::Result<()> {
+        let dir = tempfile::tempdir()?;
+        File::create(dir.path().join("dune-project"))?.sync_all()?;
+
+        let actual = render_module("ocaml", dir.path(), None);
+        let expected = Some(format!("via {} ", Color::Yellow.bold().paint("🐫 v4.10.0")));
+        assert_eq!(expected, actual);
+        dir.close()
+    }
+
+    #[test]
+    fn folder_with_jbuild() -> io::Result<()> {
+        let dir = tempfile::tempdir()?;
+        File::create(dir.path().join("jbuild"))?.sync_all()?;
+
+        let actual = render_module("ocaml", dir.path(), None);
+        let expected = Some(format!("via {} ", Color::Yellow.bold().paint("🐫 v4.10.0")));
+        assert_eq!(expected, actual);
+        dir.close()
+    }
+
+    #[test]
+    fn folder_with_jbuild_ignore() -> io::Result<()> {
+        let dir = tempfile::tempdir()?;
+        File::create(dir.path().join("jbuild-ignore"))?.sync_all()?;
+
+        let actual = render_module("ocaml", dir.path(), None);
+        let expected = Some(format!("via {} ", Color::Yellow.bold().paint("🐫 v4.10.0")));
+        assert_eq!(expected, actual);
+        dir.close()
+    }
+
+    #[test]
+    fn folder_with_merlin_file() -> io::Result<()> {
+        let dir = tempfile::tempdir()?;
+        File::create(dir.path().join(".merlin"))?.sync_all()?;
+
+        let actual = render_module("ocaml", dir.path(), None);
+        let expected = Some(format!("via {} ", Color::Yellow.bold().paint("🐫 v4.10.0")));
+        assert_eq!(expected, actual);
+        dir.close()
+    }
+
+    #[test]
+    fn folder_with_ml_file() -> io::Result<()> {
+        let dir = tempfile::tempdir()?;
+        File::create(dir.path().join("any.ml"))?.sync_all()?;
+
+        let actual = render_module("ocaml", dir.path(), None);
+        let expected = Some(format!("via {} ", Color::Yellow.bold().paint("🐫 v4.10.0")));
+        assert_eq!(expected, actual);
+        dir.close()
+    }
+
+    #[test]
+    fn folder_with_mli_file() -> io::Result<()> {
+        let dir = tempfile::tempdir()?;
+        File::create(dir.path().join("any.mli"))?.sync_all()?;
+
+        let actual = render_module("ocaml", dir.path(), None);
+        let expected = Some(format!("via {} ", Color::Yellow.bold().paint("🐫 v4.10.0")));
+        assert_eq!(expected, actual);
+        dir.close()
+    }
+
+    #[test]
+    fn folder_with_re_file() -> io::Result<()> {
+        let dir = tempfile::tempdir()?;
+        File::create(dir.path().join("any.re"))?.sync_all()?;
+
+        let actual = render_module("ocaml", dir.path(), None);
+        let expected = Some(format!("via {} ", Color::Yellow.bold().paint("🐫 v4.10.0")));
+        assert_eq!(expected, actual);
+        dir.close()
+    }
+
+    #[test]
+    fn folder_with_rei_file() -> io::Result<()> {
+        let dir = tempfile::tempdir()?;
+        File::create(dir.path().join("any.rei"))?.sync_all()?;
+
+        let actual = render_module("ocaml", dir.path(), None);
+        let expected = Some(format!("via {} ", Color::Yellow.bold().paint("🐫 v4.10.0")));
+        assert_eq!(expected, actual);
+        dir.close()
+    }
+}

src/utils.rs

@@ -63,6 +63,10 @@ pub fn exec_cmd(cmd: &str, args: &[&str]) -> Option<CommandOutput> {
             stdout: String::from("v12.0.0"),
             stderr: String::default(),
         }),
+        "ocaml -vnum" => Some(CommandOutput {
+            stdout: String::from("4.10.0"),
+            stderr: String::default(),
+        }),
         "php -r echo PHP_MAJOR_VERSION.'.'.PHP_MINOR_VERSION.'.'.PHP_RELEASE_VERSION;" => {
             Some(CommandOutput {
                 stdout: String::from("7.3.8"),