diff --git a/changelog.d/20240102_174335_GitHub_Actions_mkcws-tests.ron b/changelog.d/20240102_174335_GitHub_Actions_mkcws-tests.ron
new file mode 100644
index 00000000..8b464e2e
--- /dev/null
+++ b/changelog.d/20240102_174335_GitHub_Actions_mkcws-tests.ron
@@ -0,0 +1,8 @@
+(
+  references: {},
+  changes: {
+    "Added": [
+      "mkcws:  unit tests",
+    ],
+  },
+)
diff --git a/src/utilities.rs b/src/utilities.rs
index e1b3e03a..ee0e513b 100644
--- a/src/utilities.rs
+++ b/src/utilities.rs
@@ -46,9 +46,20 @@ impl Mkcws {
         self.output_file.truncate(Box::new(
             "{ \"folders\" : [ { \"path\" : \"".to_string()
                 + &format!("{}", self.directory.display())
-                + "\", }, ], \"settings\" : [], }\n",
+                + "\" } ] }\n",
         ))
     }
+
+    /// Create a new instance.
+    pub fn new<T>(directory: T, output_file: Option<T>) -> Self
+    where
+        std::path::PathBuf: From<T>,
+    {
+        Self {
+            directory: std::path::PathBuf::from(directory),
+            output_file: output_file.map(Into::into),
+        }
+    }
 }
 
 /// Extract Markdown code from Rust documentation comments.
diff --git a/tests/utilities.rs b/tests/utilities.rs
index 304a5443..e9a6074b 100644
--- a/tests/utilities.rs
+++ b/tests/utilities.rs
@@ -159,4 +159,21 @@ make_test!(@rs2md @twice
     rs2md_both_inner_and_outer -> true, true
 );
 
+#[cfg(feature = "mkcws")]
+#[test]
+fn mkcws() {
+    use aeruginous::ReadFile;
+
+    assert!(aeruginous::Mkcws::new(".", Some("cwd.code-workspace"))
+        .main()
+        .is_ok());
+
+    assert_eq!(
+        "cwd.code-workspace".read().unwrap(),
+        "{ \"folders\" : [ { \"path\" : \".\" } ] }\n"
+    );
+
+    std::fs::remove_file("cwd.code-workspace").unwrap();
+}
+
 /******************************************************************************/