Ensure custom variables override any basic variables

src/main.rs

@@ -60,12 +60,11 @@ fn main() {
 }
 
 fn context(user_pairs: Vec<Vec<String>>) -> Context {
-    let mut context = Context::new();
+    let mut context = basics::context();
 
     for pair in user_pairs {
         context.insert(pair[0].as_str(), pair[1].as_str());
     }
 
-    context.extend(basics::context());
     context
 }

tests/cli.rs

@@ -65,3 +65,21 @@ fn with_argument_variables() -> Result<(), Box<dyn std::error::Error>> {
 
     Ok(())
 }
+
+#[test]
+fn with_argument_variable_that_overrides_basic() -> Result<(), Box<dyn std::error::Error>> {
+    let mut file = NamedTempFile::new()?;
+    // We need to escape the {{, with two more {{.
+    writeln!(file, "Invoice date {{{{ date }}}}")?;
+
+    let mut cmd = Command::cargo_bin("blek")?;
+    cmd.arg(file.path());
+    cmd.arg("--var");
+    cmd.arg("date=2010");
+
+    cmd.assert()
+        .success()
+        .stdout(predicate::str::contains("Invoice date 2010"));
+
+    Ok(())
+}