feat(nim): Add Nim module (#1189)

* Nim module and tests

* Add nim to docs

* parse_nim_version refactor, add nim desc

* Add nim symbol to Nerd Font preset

* Yellow with v prefix as default version

* Nim version fmt fix

* Update docs/config/README.md

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

* Update src/modules/nim.rs

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

* Nim module and tests

* Add nim to docs

* Yellow with v prefix as default version

* Update docs/config/README.md

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

* Update src/modules/nim.rs

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

* Add nim to docs, proper version formatting.

* Remove v from symbol, add to fmt string

* cargo fmt

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

9 files changed, 205 insertions, 9 deletions

diff --git a/docs/config/README.md b/docs/config/README.md
index d47df257d..d0380e724 100644
--- a/docs/config/README.md
+++ b/docs/config/README.md
@@ -115,6 +115,7 @@ prompt_order = [
     "haskell",
     "java",
     "julia",
+    "nim",
     "nodejs",
     "ocaml",
     "php",
@@ -1016,6 +1017,33 @@ truncation_length = 4
 truncation_symbol = ""
 ```
 
+## Nim
+
+The `nim` module shows the currently installed version of Nim.
+The module will be shown if any of the following conditions are met:
+- The current directory contains a `nim.cfg` file
+- The current directory contains a file with the `.nim` extension
+- The current directory contains a file with the `.nims` extension
+- The current directory contains a file with the `.nimble` extension
+
+### Options
+
+| Variable   | Default         | Description                                            |
+| ---------- | --------------- | ------------------------------------------------------ |
+| `symbol`   | `"👑 "`         | The symbol used before displaying the version of Nim.  |
+| `style`    | `"bold yellow"` | The style for the module.                              |
+| `disabled` | `false`         | Disables the `nim` module.                             |
+
+### Example
+
+```toml
+# ~/.config/starship.toml
+
+[nim]
+style = "yellow"
+symbol = "🎣 "
+```
+
 ## Nix-shell
 
 The `nix_shell` module shows the nix-shell environment.
diff --git a/docs/presets/README.md b/docs/presets/README.md
index 7441a3f26..a3241b09c 100644
--- a/docs/presets/README.md
+++ b/docs/presets/README.md
@@ -58,6 +58,9 @@ symbol = " "
 [memory_usage]
 symbol = " "
 
+[nim]
+symbol = " "
+
 [nix_shell]
 symbol = " "
 
diff --git a/src/configs/mod.rs b/src/configs/mod.rs
index 1f695a66d..48badefbc 100644
--- a/src/configs/mod.rs
+++ b/src/configs/mod.rs
@@ -25,6 +25,7 @@ pub mod jobs;
 pub mod julia;
 pub mod kubernetes;
 pub mod memory_usage;
+pub mod nim;
 pub mod nix_shell;
 pub mod nodejs;
 pub mod ocaml;
diff --git a/src/configs/nim.rs b/src/configs/nim.rs
new file mode 100644
index 000000000..c975656a4
--- /dev/null
+++ b/src/configs/nim.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 NimConfig<'a> {
+    pub symbol: SegmentConfig<'a>,
+    pub version: SegmentConfig<'a>,
+    pub style: Style,
+    pub disabled: bool,
+}
+
+impl<'a> RootModuleConfig<'a> for NimConfig<'a> {
+    fn new() -> Self {
+        NimConfig {
+            symbol: SegmentConfig::new("👑 "),
+            version: SegmentConfig::default(),
+            style: Color::Yellow.bold(),
+            disabled: false,
+        }
+    }
+}
diff --git a/src/configs/starship_root.rs b/src/configs/starship_root.rs
index 18eaeee73..f42481257 100644
--- a/src/configs/starship_root.rs
+++ b/src/configs/starship_root.rs
@@ -39,6 +39,7 @@ impl<'a> RootModuleConfig<'a> for StarshipRootConfig<'a> {
                 "haskell",
                 "java",
                 "julia",
+                "nim",
                 "nodejs",
                 "ocaml",
                 "php",
diff --git a/src/module.rs b/src/module.rs
index a3784212c..aa1ad1553 100644
--- a/src/module.rs
+++ b/src/module.rs
@@ -37,6 +37,7 @@ pub const ALL_MODULES: &[&str] = &[
     "kubernetes",
     "line_break",
     "memory_usage",
+    "nim",
     "nix_shell",
     "nodejs",
     "ocaml",
diff --git a/src/modules/mod.rs b/src/modules/mod.rs
index 26b69e4f6..1a73a1a22 100644
--- a/src/modules/mod.rs
+++ b/src/modules/mod.rs
@@ -26,6 +26,7 @@ mod julia;
 mod kubernetes;
 mod line_break;
 mod memory_usage;
+mod nim;
 mod nix_shell;
 mod nodejs;
 mod ocaml;
@@ -80,6 +81,7 @@ pub fn handle<'a>(module: &str, context: &'a Context) -> Option<Module<'a>> {
         "kubernetes" => kubernetes::module(context),
         "line_break" => line_break::module(context),
         "memory_usage" => memory_usage::module(context),
+        "nim" => nim::module(context),
         "nix_shell" => nix_shell::module(context),
         "nodejs" => nodejs::module(context),
         "ocaml" => ocaml::module(context),
@@ -131,6 +133,7 @@ pub fn description(module: &str) -> &'static str {
         "kubernetes" => "The current Kubernetes context name and, if set, the namespace",
         "line_break" => "Separates the prompt into two lines",
         "memory_usage" => "Current system memory and swap usage",
+        "nim" => "The currently installed version of Nim",
         "nix_shell" => "The nix-shell environment",
         "nodejs" => "The currently installed version of NodeJS",
         "ocaml" => "The currently installed version of OCaml",
diff --git a/src/modules/nim.rs b/src/modules/nim.rs
new file mode 100644
index 000000000..5b064bc58
--- /dev/null
+++ b/src/modules/nim.rs
@@ -0,0 +1,125 @@
+use super::{Context, Module, RootModuleConfig, SegmentConfig};
+
+use crate::configs::nim::NimConfig;
+use crate::utils;
+
+/// Creates a module with the current Nim version
+///
+/// Will display the Nim version if any of the following criteria are met:
+///     - The current directory contains a file with extension `.nim`, `.nims`, or `.nimble`
+///     - The current directory contains a `nim.cfg` file
+pub fn module<'a>(context: &'a Context) -> Option<Module<'a>> {
+    let is_nim_project = context
+        .try_begin_scan()?
+        .set_files(&["nim.cfg"])
+        .set_extensions(&["nim", "nims", "nimble"])
+        .is_match();
+
+    if !is_nim_project {
+        return None;
+    }
+
+    let nim_version_output = utils::exec_cmd("nim", &["--version"])?.stdout;
+    let formatted_nim_version = format!("v{}", parse_nim_version(&nim_version_output)?);
+
+    let mut module = context.new_module("nim");
+    let config = NimConfig::try_load(module.config);
+
+    module.set_style(config.style);
+
+    module.create_segment("symbol", &config.symbol);
+    module.create_segment("version", &SegmentConfig::new(&formatted_nim_version));
+
+    Some(module)
+}
+
+fn parse_nim_version(version_cmd_output: &str) -> Option<&str> {
+    version_cmd_output
+        .lines()
+        // First line has the version
+        .next()?
+        .split(' ')
+        .find(|&s| s.chars().all(|c| c >= '0' && c <= '9' || c == '.'))
+}
+
+#[cfg(test)]
+mod tests {
+    use super::parse_nim_version;
+    use crate::modules::utils::test::render_module;
+    use ansi_term::Color;
+    use std::fs::File;
+    use std::io;
+
+    #[test]
+    fn nim_version() {
+        let ok_versions = ["1.1.1", "2", "."];
+        let not_ok_versions = ["abc", " \n.", ". ", "abc."];
+
+        let all_some = ok_versions.iter().all(|&v| parse_nim_version(v).is_some());
+        let all_none = not_ok_versions
+            .iter()
+            .any(|&v| parse_nim_version(v).is_some());
+
+        assert_eq!(true, all_some);
+        assert_eq!(true, all_none);
+
+        let sample_nimc_output = "Nim Compiler Version 1.2.0 [Linux: amd64]
+            Compiled at 2020-04-03
+            Copyright (c) 2006-2020 by Andreas Rumpf
+
+            git hash: 7e83adff84be5d0c401a213eccb61e321a3fb1ff
+            active boot switches: -d:release\n";
+
+        assert_eq!(Some("1.2.0"), parse_nim_version(sample_nimc_output))
+    }
+
+    #[test]
+    fn folder_without_nim() -> io::Result<()> {
+        let dir = tempfile::tempdir()?;
+        File::create(dir.path().join("nim.txt"))?.sync_all()?;
+        let actual = render_module("nim", dir.path(), None);
+        let expected = None;
+        assert_eq!(expected, actual);
+        dir.close()
+    }
+
+    #[test]
+    fn folder_with_nimble_file() -> io::Result<()> {
+        let dir = tempfile::tempdir()?;
+        File::create(dir.path().join("main.nimble"))?.sync_all()?;
+        let actual = render_module("nim", dir.path(), None);
+        let expected = Some(format!("via {} ", Color::Yellow.bold().paint("👑 v1.2.0")));
+        assert_eq!(expected, actual);
+        dir.close()
+    }
+
+    #[test]
+    fn folder_with_nim_file() -> io::Result<()> {
+        let dir = tempfile::tempdir()?;
+        File::create(dir.path().join("main.nim"))?.sync_all()?;
+        let actual = render_module("nim", dir.path(), None);
+        let expected = Some(format!("via {} ", Color::Yellow.bold().paint("👑 v1.2.0")));
+        assert_eq!(expected, actual);
+        dir.close()
+    }
+
+    #[test]
+    fn folder_with_nims_file() -> io::Result<()> {
+        let dir = tempfile::tempdir()?;
+        File::create(dir.path().join("main.nims"))?.sync_all()?;
+        let actual = render_module("nim", dir.path(), None);
+        let expected = Some(format!("via {} ", Color::Yellow.bold().paint("👑 v1.2.0")));
+        assert_eq!(expected, actual);
+        dir.close()
+    }
+
+    #[test]
+    fn folder_with_cfg_file() -> io::Result<()> {
+        let dir = tempfile::tempdir()?;
+        File::create(dir.path().join("cfg.nim"))?.sync_all()?;
+        let actual = render_module("nim", dir.path(), None);
+        let expected = Some(format!("via {} ", Color::Yellow.bold().paint("👑 v1.2.0")));
+        assert_eq!(expected, actual);
+        dir.close()
+    }
+}
diff --git a/src/utils.rs b/src/utils.rs
index 687544d68..7687a300b 100644
--- a/src/utils.rs
+++ b/src/utils.rs
@@ -47,6 +47,15 @@ pub fn exec_cmd(cmd: &str, args: &[&str]) -> Option<CommandOutput> {
             stdout: String::from("stdout ok!"),
             stderr: String::from("stderr ok!"),
         }),
+        "elixir --version" => Some(CommandOutput {
+            stdout: String::from(
+                "\
+Erlang/OTP 22 [erts-10.6.4] [source] [64-bit] [smp:8:8] [ds:8:8:10] [async-threads:1] [hipe]
+
+Elixir 1.10 (compiled with Erlang/OTP 22)",
+            ),
+            stderr: String::default(),
+        }),
         "elm --version" => Some(CommandOutput {
             stdout: String::from("0.19.1"),
             stderr: String::default(),
@@ -59,6 +68,17 @@ pub fn exec_cmd(cmd: &str, args: &[&str]) -> Option<CommandOutput> {
             stdout: String::from("julia version 1.4.0"),
             stderr: String::default(),
         }),
+        "nim --version" => Some(CommandOutput {
+            stdout: String::from(
+                "\
+Nim Compiler Version 1.2.0 [Linux: amd64]
+Compiled at 2020-04-03
+Copyright (c) 2006-2020 by Andreas Rumpf
+git hash: 7e83adff84be5d0c401a213eccb61e321a3fb1ff
+active boot switches: -d:release\n",
+            ),
+            stderr: String::default(),
+        }),
         "node --version" => Some(CommandOutput {
             stdout: String::from("v12.0.0"),
             stderr: String::default(),
@@ -87,15 +107,6 @@ pub fn exec_cmd(cmd: &str, args: &[&str]) -> Option<CommandOutput> {
                 stderr: String::default(),
             })
         }
-        "elixir --version" => Some(CommandOutput {
-            stdout: String::from(
-                "\
-Erlang/OTP 22 [erts-10.6.4] [source] [64-bit] [smp:8:8] [ds:8:8:10] [async-threads:1] [hipe]
-
-Elixir 1.10 (compiled with Erlang/OTP 22)",
-            ),
-            stderr: String::default(),
-        }),
         "zig version" => Some(CommandOutput {
             stdout: String::from("0.6.0"),
             stderr: String::default(),