feat: add comprehensive Scala test suite

- Add Scala language support tests for code extraction functionality
- Include unit tests for Scala file extension mapping
- Add integration tests for Scala parser (functions, classes, objects, traits, enums)
- Add Scala comment processing tests with special characters
- Add comprehensive typing core tests with snapshot validation
- Create dedicated test structure in tests/integration/languages/scala/
- Add helper function for consistent test extraction options

Tests cover various Scala constructs:
- Functions (def statements)
- Classes and case classes
- Objects and case objects
- Traits and sealed traits
- Enums with pattern matching
- Higher-order functions and for comprehensions
- Comment handling for both // and /* */ styles

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

Author: unhappychoice

tests/integration/comment_processing_tests.rs

@@ -443,4 +443,79 @@ functionB();"#;
             );
         }
     }
+
+    #[test]
+    fn test_scala_comment_processing() {
+        let scala_code = r#"// Scala object definition with comments
+object Calculator {
+  /* Multi-line comment
+     with calculations */
+  def add(x: Int, y: Int): Int = x + y
+  
+  // Single line comment for multiplication
+  def multiply(x: Int, y: Int): Int = {
+    /* Another block comment */
+    x * y
+  }
+}
+
+class MathUtils {
+  // Comment with special symbols: → ← ↑ ↓
+  def factorial(n: Int): Int = {
+    if (n <= 1) 1 else n * factorial(n - 1)
+  }
+}"#;
+
+        // Find all comment ranges manually for testing
+        let comment_ranges = vec![
+            // First single-line comment
+            (0, "// Scala object definition with comments".len()),
+            // Multi-line comment
+            (scala_code.find("/* Multi-line comment").unwrap(),
+             scala_code.find("calculations */").unwrap() + "calculations */".len()),
+            // Single line comment for multiplication
+            (scala_code.find("// Single line comment").unwrap(),
+             scala_code.find("multiplication").unwrap() + "multiplication".len()),
+            // Another block comment
+            (scala_code.find("/* Another block comment").unwrap(),
+             scala_code.find("comment */").unwrap() + "comment */".len()),
+            // Comment with special symbols
+            (scala_code.find("// Comment with special").unwrap(),
+             scala_code.find("↑ ↓").unwrap() + "↑ ↓".len()),
+        ];
+
+        println!("=== Scala Comment Processing Test ===");
+        println!("Code: {}", scala_code);
+        println!("Comment ranges: {:?}", comment_ranges);
+
+        let typing_core = TypingCore::new(scala_code, &comment_ranges, Default::default());
+        let display_ranges = typing_core.display_comment_ranges();
+
+        println!("Display text: {}", typing_core.text_to_display());
+        println!("Display ranges: {:?}", display_ranges);
+
+        // Should find all comment ranges
+        assert_eq!(
+            display_ranges.len(),
+            comment_ranges.len(),
+            "Should find all Scala comments"
+        );
+
+        for (i, &(start, end)) in display_ranges.iter().enumerate() {
+            let display_text = typing_core.text_to_display();
+            let comment = &display_text[start..end];
+            println!("Comment {}: {:?}", i, comment);
+
+            // Verify comments contain expected content
+            match i {
+                0 => assert!(comment.contains("Scala object"), "Should contain 'Scala object'"),
+                1 => assert!(comment.contains("Multi-line") && comment.contains("calculations"), 
+                           "Should contain multi-line comment content"),
+                2 => assert!(comment.contains("multiplication"), "Should contain 'multiplication'"),
+                3 => assert!(comment.contains("Another block"), "Should contain 'Another block'"),
+                4 => assert!(comment.contains("→ ← ↑ ↓"), "Should contain special symbols"),
+                _ => {}
+            }
+        }
+    }
 }

tests/integration/languages/mod.rs

@@ -11,6 +11,7 @@ pub mod php;
 pub mod python;
 pub mod ruby;
 pub mod rust;
+pub mod scala;
 pub mod swift;
 pub mod typescript;