1 files changed, 187 insertions, 0 deletions
diff --git a/just_template/src/test_expand.rs b/just_template/src/test_expand.rs
new file mode 100644
index 0000000..9132f6e
--- /dev/null
+++ b/just_template/src/test_expand.rs
@@ -0,0 +1,187 @@
+use std::collections::HashMap;
+
+use crate::Template;
+
+#[test]
+fn basic_param() {
+    let mut tmpl = Template::from("Hello, <<<name>>>!".to_string());
+    tmpl.insert_param("name".to_string(), "World".to_string());
+    assert_eq!(tmpl.expand().unwrap(), "Hello, World!");
+}
+
+#[test]
+fn multi_param() {
+    let mut tmpl = Template::from("<<<a>>> + <<<b>>> = <<<c>>>".to_string());
+    tmpl.insert_param("a".to_string(), "1".to_string());
+    tmpl.insert_param("b".to_string(), "2".to_string());
+    tmpl.insert_param("c".to_string(), "3".to_string());
+    assert_eq!(tmpl.expand().unwrap(), "1 + 2 = 3");
+}
+
+#[test]
+fn impl_blocks() {
+    let mut tmpl = Template::from(
+        r#"
+>>>>>>>>>> arms
+@@@ >>> arms
+    "<<<crate_name>>>" => Some(<<<crate_name>>>::exec(data, params).await),
+@@@ <<<
+"#
+        .trim()
+        .to_string(),
+    );
+
+    let arms = tmpl.add_impl("arms".to_string());
+    arms.push(HashMap::from([(
+        "crate_name".to_string(),
+        "my".to_string(),
+    )]));
+    arms.push(HashMap::from([(
+        "crate_name".to_string(),
+        "you".to_string(),
+    )]));
+
+    let expanded = tmpl.expand().unwrap();
+    assert!(expanded.contains(r#""my" => Some(my::exec(data, params).await)"#));
+    assert!(expanded.contains(r#""you" => Some(you::exec(data, params).await)"#));
+}
+
+#[test]
+fn display_block_global_hidden_by_default() {
+    let tmpl = Template::from(
+        r#"
+visible line
+??? >>> debug
+    hidden line
+??? <<<
+visible end
+"#
+        .trim()
+        .to_string(),
+    );
+
+    let expanded = tmpl.expand().unwrap();
+    assert!(expanded.contains("visible line"));
+    assert!(expanded.contains("visible end"));
+    assert!(!expanded.contains("hidden line"));
+}
+
+#[test]
+fn display_block_global_shown_via_param() {
+    let mut tmpl = Template::from(
+        r#"
+visible line
+??? >>> debug
+    shown line
+??? <<<
+visible end
+"#
+        .trim()
+        .to_string(),
+    );
+
+    tmpl.insert_param("debug".to_string(), "".to_string());
+
+    let expanded = tmpl.expand().unwrap();
+    assert!(expanded.contains("visible line"));
+    assert!(expanded.contains("visible end"));
+    assert!(expanded.contains("shown line"));
+}
+
+#[test]
+fn display_block_inside_impl_area_hidden_by_default() {
+    let mut tmpl = Template::from(
+        r#"
+>>>>>>>>>> arms
+@@@ >>> arms
+    <<<crate_name>>> => exec,
+??? >>> extra
+    <<<crate_name>>> => metrics,
+??? <<<
+@@@ <<<
+"#
+        .trim()
+        .to_string(),
+    );
+
+    let arms = tmpl.add_impl("arms".to_string());
+    arms.push(HashMap::from([(
+        "crate_name".to_string(),
+        "my".to_string(),
+    )]));
+
+    let expanded = tmpl.expand().unwrap();
+    assert!(expanded.contains(r#"my => exec"#));
+    assert!(!expanded.contains(r#"my => metrics"#));
+}
+
+#[test]
+fn display_block_inside_impl_area_shown_by_global_param() {
+    let mut tmpl = Template::from(
+        r#"
+>>>>>>>>>> arms
+@@@ >>> arms
+    <<<crate_name>>> => exec,
+??? >>> extra
+    <<<crate_name>>> => metrics,
+??? <<<
+@@@ <<<
+"#
+        .trim()
+        .to_string(),
+    );
+
+    // Enable via global param — shows for ALL arms
+    tmpl.insert_param("extra".to_string(), "".to_string());
+
+    let arms = tmpl.add_impl("arms".to_string());
+    arms.push(HashMap::from([(
+        "crate_name".to_string(),
+        "my".to_string(),
+    )]));
+    arms.push(HashMap::from([(
+        "crate_name".to_string(),
+        "you".to_string(),
+    )]));
+
+    let expanded = tmpl.expand().unwrap();
+    assert!(expanded.contains(r#"my => exec"#));
+    assert!(expanded.contains(r#"my => metrics"#));
+    assert!(expanded.contains(r#"you => exec"#));
+    assert!(expanded.contains(r#"you => metrics"#));
+}
+
+#[test]
+fn display_block_inside_impl_area_shown_by_arm_param() {
+    let mut tmpl = Template::from(
+        r#"
+>>>>>>>>>> arms
+@@@ >>> arms
+    <<<crate_name>>> => exec,
+??? >>> extra
+    <<<crate_name>>> => metrics,
+??? <<<
+@@@ <<<
+"#
+        .trim()
+        .to_string(),
+    );
+
+    let arms = tmpl.add_impl("arms".to_string());
+    // Arm 1: no "extra" → hidden
+    arms.push(HashMap::from([(
+        "crate_name".to_string(),
+        "my".to_string(),
+    )]));
+    // Arm 2: has "extra" → shown for this arm only
+    arms.push(HashMap::from([
+        ("crate_name".to_string(), "you".to_string()),
+        ("extra".to_string(), "".to_string()),
+    ]));
+
+    let expanded = tmpl.expand().unwrap();
+    assert!(expanded.contains(r#"my => exec"#));
+    assert!(!expanded.contains(r#"my => metrics"#));
+    assert!(expanded.contains(r#"you => exec"#));
+    assert!(expanded.contains(r#"you => metrics"#));
+}