feat(PureScript): Add Purescript module (#1227)

* Added configs/purescript

* Added modules/purescript

* Added necessary codes

* Added tests

* Updated README

* Fixed color because black is hard to see

* Fixed of push mistake

* Fixed pointed out in PR

2 files changed, 75 insertions, 0 deletions

diff --git a/src/modules/mod.rs b/src/modules/mod.rs
index 39993de13..26b69e4f6 100644
--- a/src/modules/mod.rs
+++ b/src/modules/mod.rs
@@ -31,6 +31,7 @@ mod nodejs;
 mod ocaml;
 mod package;
 mod php;
+mod purescript;
 mod python;
 mod ruby;
 mod rust;
@@ -84,6 +85,7 @@ pub fn handle<'a>(module: &str, context: &'a Context) -> Option<Module<'a>> {
         "ocaml" => ocaml::module(context),
         "package" => package::module(context),
         "php" => php::module(context),
+        "purescript" => purescript::module(context),
         "python" => python::module(context),
         "ruby" => ruby::module(context),
         "rust" => rust::module(context),
@@ -134,6 +136,7 @@ pub fn description(module: &str) -> &'static str {
         "ocaml" => "The currently installed version of OCaml",
         "package" => "The package version of the current directory's project",
         "php" => "The currently installed version of PHP",
+        "purescript" => "The currently installed version of PureScript",
         "python" => "The currently installed version of Python",
         "ruby" => "The currently installed version of Ruby",
         "rust" => "The currently installed version of Rust",
diff --git a/src/modules/purescript.rs b/src/modules/purescript.rs
new file mode 100644
index 000000000..2ca3d20f9
--- /dev/null
+++ b/src/modules/purescript.rs
@@ -0,0 +1,72 @@
+use super::{Context, Module, RootModuleConfig, SegmentConfig};
+
+use crate::configs::purescript::PureScriptConfig;
+use crate::utils;
+
+/// Creates a module with the current PureScript version
+///
+/// Will display the PureScript version if any of the following criteria are met:
+///     - Current directory contains a `spago.dhall` file
+///     - Current directory contains a `*.purs` files
+pub fn module<'a>(context: &'a Context) -> Option<Module<'a>> {
+    let is_purs_project = context
+        .try_begin_scan()?
+        .set_files(&["spago.dhall"])
+        .set_extensions(&["purs"])
+        .is_match();
+
+    if !is_purs_project {
+        return None;
+    }
+
+    let purs_version = utils::exec_cmd("purs", &["--version"])?.stdout;
+    let formatted_version = Some(format!("v{}", purs_version.trim()))?;
+
+    let mut module = context.new_module("purescript");
+    let config: PureScriptConfig = PureScriptConfig::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::File;
+    use std::io;
+
+    #[test]
+    fn folder_without_purescript_files() -> io::Result<()> {
+        let dir = tempfile::tempdir()?;
+        let actual = render_module("purescript", dir.path(), None);
+        let expected = None;
+        assert_eq!(expected, actual);
+        dir.close()
+    }
+
+    #[test]
+    fn folder_with_purescript_file() -> io::Result<()> {
+        let dir = tempfile::tempdir()?;
+        File::create(dir.path().join("Main.purs"))?.sync_all()?;
+
+        let actual = render_module("purescript", dir.path(), None);
+        let expected = Some(format!("via {} ", Color::White.bold().paint("<=> v0.13.5")));
+        assert_eq!(expected, actual);
+        dir.close()
+    }
+
+    #[test]
+    fn folder_with_spago_file() -> io::Result<()> {
+        let dir = tempfile::tempdir()?;
+        File::create(dir.path().join("spago.dhall"))?.sync_all()?;
+
+        let actual = render_module("purescript", dir.path(), None);
+        let expected = Some(format!("via {} ", Color::White.bold().paint("<=> v0.13.5")));
+        assert_eq!(expected, actual);
+        dir.close()
+    }
+}