feat: add Haskell Stack support (#546)

Add a Haskell Stack module when a stack.yaml file is detected

.github/workflows/workflow.yml

@@ -116,6 +116,23 @@ jobs:
           toolchain: stable
           override: true
 
+      # Install Stack at a fixed version (Linux & macOS version)
+      - name: Install Stack [-nix]
+        if: matrix.os != 'windows-latest'
+        uses: mstksg/setup-stack@v1
+
+      # Install Stack at a fixed version (Windows version), use Chocolatey
+      - name: Install Stack [-windows]
+        if: matrix.os == 'windows-latest'
+        uses: crazy-max/ghaction-chocolatey@v1
+        with:
+          args: install haskell-stack -y
+
+      - name: Install GHC version
+        env:
+          ARGS: --resolver nightly-2019-09-21
+        run: stack $ARGS ghc -- --numeric-version --no-install-ghc
+
       # Install Node.js at a fixed version
       - uses: actions/setup-node@v1
         with:

README.md

@@ -89,8 +89,9 @@ The prompt shows information you need while you're working, while staying sleek
 
 - Prompt character turns red if the last command exits with non-zero code
 - Current Go version (`🐹`)
-- Current Java version (`☕`)
-- Current Node.js version (`⬢`)
+- Current Haskell version (`λ`)
+- Current Java version(`☕`)
+- Current Node.js version(`⬢`)
 - Current PHP version (`🐘`)
 - Current Python version (`🐍`)
 - Current Ruby version (`💎`)

docs/config/README.md

@@ -99,6 +99,7 @@ prompt_order = [
     "git_commit",
     "git_state",
     "git_status",
+    "haskell",
     "hg_branch",
     "package",
     "dotnet",
@@ -610,6 +611,30 @@ The module will be shown if any of the following conditions are met:
 [golang]
 symbol = "🏎💨 "
 ```
+## Haskell
+
+The `haskell` module shows the currently installed version of Haskell Stack version.
+The module will be shown if any of the following conditions are met:
+
+- The current directory contains a `stack.yaml` file
+
+### Options
+
+| Variable   | Default       | Description                                               |
+| ---------- | ------------- | --------------------------------------------------------- |
+| `symbol`   | `"λ "`        | The symbol used before displaying the version of Haskell. |
+| `style`    | `"bold red"`  | The style for the module.                                 |
+| `disabled` | `false`       | Disables the `haskell` module.                            |
+
+
+### Example
+
+```toml
+# ~/.config/starship.toml
+
+[haskell]
+symbol = "λx.x "
+```
 
 ## Mercurial Branch
 

src/configs/haskell.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 HaskellConfig<'a> {
+    pub symbol: SegmentConfig<'a>,
+    pub version: SegmentConfig<'a>,
+    pub style: Style,
+    pub disabled: bool,
+}
+
+impl<'a> RootModuleConfig<'a> for HaskellConfig<'a> {
+    fn new() -> Self {
+        HaskellConfig {
+            symbol: SegmentConfig::new("λ "),
+            version: SegmentConfig::default(),
+            style: Color::Red.bold(),
+            disabled: false,
+        }
+    }
+}

src/configs/mod.rs

@@ -11,6 +11,7 @@ pub mod git_commit;
 pub mod git_state;
 pub mod git_status;
 pub mod go;
+pub mod haskell;
 pub mod hg_branch;
 pub mod hostname;
 pub mod java;

src/module.rs

@@ -22,6 +22,7 @@ pub const ALL_MODULES: &[&str] = &[
     "git_state",
     "git_status",
     "golang",
+    "haskell",
     "hg_branch",
     "hostname",
     "java",

src/modules/haskell.rs

@@ -0,0 +1,40 @@
+use super::{Context, Module, RootModuleConfig, SegmentConfig};
+
+use crate::configs::haskell::HaskellConfig;
+use crate::utils;
+
+/// Creates a module with the current Haskell Stack version
+///
+/// Will display the Haskell version if any of the following criteria are met:
+///     - Current directory contains a `stack.yaml` file
+pub fn module<'a>(context: &'a Context) -> Option<Module<'a>> {
+    let is_haskell_project = context
+        .try_begin_scan()?
+        .set_files(&["stack.yaml"])
+        .is_match();
+
+    if !is_haskell_project {
+        return None;
+    }
+
+    let haskell_version = utils::exec_cmd(
+        "stack",
+        &["ghc", "--", "--numeric-version", "--no-install-ghc"],
+    )?
+    .stdout;
+    let formatted_version = format_haskell_version(&haskell_version)?;
+
+    let mut module = context.new_module("haskell");
+    let config: HaskellConfig = HaskellConfig::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)
+}
+
+fn format_haskell_version(haskell_version: &str) -> Option<String> {
+    let formatted_version = format!("v{}", haskell_version.trim());
+    Some(formatted_version)
+}

src/modules/mod.rs

@@ -11,6 +11,7 @@ mod git_commit;
 mod git_state;
 mod git_status;
 mod golang;
+mod haskell;
 mod hg_branch;
 mod hostname;
 mod java;
@@ -55,6 +56,7 @@ pub fn handle<'a>(module: &str, context: &'a Context) -> Option<Module<'a>> {
         "git_state" => git_state::module(context),
         "git_status" => git_status::module(context),
         "golang" => golang::module(context),
+        "haskell" => haskell::module(context),
         "hg_branch" => hg_branch::module(context),
         "hostname" => hostname::module(context),
         "java" => java::module(context),

tests/testsuite/haskell.rs

@@ -0,0 +1,71 @@
+use ansi_term::Color;
+use dirs::home_dir;
+use std::fs::{File, OpenOptions};
+use std::io::{self, Write};
+use tempfile::{self, TempDir};
+
+use crate::common;
+
+#[test]
+fn folder_without_stack_yaml() -> io::Result<()> {
+    let dir = tempfile::tempdir()?;
+
+    let output = common::render_module("haskell")
+        .arg("--path")
+        .arg(dir.path())
+        .output()?;
+    let actual = String::from_utf8(output.stdout).unwrap();
+
+    let expected = "";
+    assert_eq!(expected, actual);
+    Ok(())
+}
+
+#[test]
+#[ignore]
+#[cfg(not(windows))]
+fn folder_with_stack_yaml() -> io::Result<()> {
+    let dir = tempfile::tempdir()?;
+    create_dummy_haskell_project(&dir, Some("nightly-2019-09-21 # Last GHC 8.6.5"))?;
+
+    let output = if cfg!(windows) {
+        let mut app_data = home_dir().unwrap();
+        app_data.push("AppData");
+        app_data.push("Local");
+        eprintln!("{}", app_data.to_str().unwrap());
+        common::render_module("haskell")
+            .env("HOME", home_dir().unwrap())
+            .env("LOCALAPPDATA", app_data)
+            .env("STACK_ROOT", r"C:\sr")
+            .arg("--path")
+            .arg(dir.path())
+            .output()?
+    } else {
+        common::render_module("haskell")
+            .env("HOME", home_dir().unwrap())
+            .arg("--path")
+            .arg(dir.path())
+            .output()?
+    };
+
+    let actual = String::from_utf8(output.stdout).unwrap();
+
+    let expected = format!("via {} ", Color::Red.bold().paint("λ v8.6.5"));
+    assert_eq!(expected, actual);
+    Ok(())
+}
+
+fn create_dummy_haskell_project(folder: &TempDir, contents: Option<&str>) -> io::Result<()> {
+    let cabal_path = folder.path().join("test.cabal");
+    File::create(cabal_path)?.sync_all()?;
+
+    let stack_yaml_path = folder.path().join("stack.yaml");
+
+    let mut stack_yaml_file = OpenOptions::new()
+        .write(true)
+        .create(true)
+        .truncate(true)
+        .open(&stack_yaml_path)?;
+    write!(stack_yaml_file, "resolver: {}", contents.unwrap_or(""))?;
+    stack_yaml_file.sync_data()
+}

tests/testsuite/main.rs

@@ -12,6 +12,7 @@ mod git_commit;
 mod git_state;
 mod git_status;
 mod golang;
+mod haskell;
 mod hg_branch;
 mod hostname;
 mod jobs;