test: port Haskell module tests to integration test (#913)

.github/workflows/workflow.yml

@@ -116,23 +116,6 @@ 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 Golang at a fixed version
       - uses: actions/setup-go@v1
         with:

src/modules/haskell.rs

@@ -22,7 +22,7 @@ pub fn module<'a>(context: &'a Context) -> Option<Module<'a>> {
         &["ghc", "--", "--numeric-version", "--no-install-ghc"],
     )?
     .stdout;
-    let formatted_version = format_haskell_version(&haskell_version)?;
+    let formatted_version = Some(format!("v{}", haskell_version.trim()))?;
 
     let mut module = context.new_module("haskell");
     let config: HaskellConfig = HaskellConfig::try_load(module.config);
@@ -34,7 +34,30 @@ pub fn module<'a>(context: &'a Context) -> Option<Module<'a>> {
     Some(module)
 }
 
-fn format_haskell_version(haskell_version: &str) -> Option<String> {
-    let formatted_version = format!("v{}", haskell_version.trim());
-    Some(formatted_version)
+#[cfg(test)]
+mod tests {
+    use crate::modules::utils::test::render_module;
+    use ansi_term::Color;
+    use std::fs::File;
+    use std::io;
+    use tempfile;
+
+    #[test]
+    fn folder_without_stack_yaml() -> io::Result<()> {
+        let dir = tempfile::tempdir()?;
+        let actual = render_module("haskell", dir.path());
+        let expected = None;
+        assert_eq!(expected, actual);
+        Ok(())
+    }
+
+    #[test]
+    fn folder_with_stack_yaml() -> io::Result<()> {
+        let dir = tempfile::tempdir()?;
+        File::create(dir.path().join("stack.yaml"))?.sync_all()?;
+        let actual = render_module("haskell", dir.path());
+        let expected = Some(format!("via {} ", Color::Red.bold().paint("λ v8.6.5")));
+        assert_eq!(expected, actual);
+        Ok(())
+    }
 }

src/utils.rs

@@ -43,6 +43,10 @@ pub fn exec_cmd(cmd: &str, args: &[&str]) -> Option<CommandOutput> {
             stdout: String::from("0.19.1"),
             stderr: String::default(),
         }),
+        "stack ghc -- --numeric-version --no-install-ghc" => Some(CommandOutput {
+            stdout: String::from("8.6.5"),
+            stderr: String::default(),
+        }),
         "node --version" => Some(CommandOutput {
             stdout: String::from("v12.0.0"),
             stderr: String::default(),

tests/testsuite/main.rs

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