feat: add Rust language support with cognitive complexity analysis

.github/workflows/ci.yml

@@ -58,6 +58,8 @@ jobs:
       # (lint is OS-agnostic and already runs on Linux via test:coverage)
       - run: npm run compile
         if: runner.os != 'Linux'
+      - run: npm run test:unit
+        if: runner.os != 'Linux'
       - run: npm run test:vscode
         if: runner.os != 'Linux'
       - name: Upload coverage to Codecov

README.md

@@ -9,7 +9,7 @@ A Visual Studio Code extension that calculates and displays **Cognitive Complexi
 - **Real-time Analysis**: Analyzes code metrics as you write code
 - **CodeLens Integration**: Shows complexity scores directly above functions
 - **Color-coded Indicators**: Visual feedback with green/yellow/red status based on configurable thresholds
-- **Multi-language Support**: Currently supports C#, Go, Java, JavaScript, JSX, Python, TypeScript, and TSX
+- **Multi-language Support**: Currently supports C#, Go, Java, JavaScript, JSX, Python, Rust, TypeScript, and TSX
 - **Configurable Thresholds**: Customize warning and error complexity thresholds
 - **Smart Exclusions**: Automatically excludes test files, build artifacts, and other specified patterns
 
@@ -23,6 +23,7 @@ A Visual Studio Code extension that calculates and displays **Cognitive Complexi
 | JavaScript | ✅ Supported | Full support including functions, methods, arrow functions, closures |
 | JSX | ✅ Supported | Full support for JavaScript with JSX syntax (React components) |
 | Python | ✅ Supported | Full support including functions, methods, lambdas, comprehensions, match statements |
+| Rust | ✅ Supported | Full support including fn items, impl methods, if/for/while/loop/match expressions |
 | TypeScript | ✅ Supported | Full support including functions, methods, arrow functions, closures |
 | TSX | ✅ Supported | Full support for TypeScript with JSX syntax (React components) |
 

package.json

@@ -31,7 +31,8 @@
     "golang",
     "metrics",
     "python",
-    "java"
+    "java",
+    "rust"
   ],
   "categories": [
     "Other"
@@ -44,7 +45,8 @@
     "onLanguage:python",
     "onLanguage:typescript",
     "onLanguage:typescriptreact",
-    "onLanguage:java"
+    "onLanguage:java",
+    "onLanguage:rust"
   ],
   "main": "./out/extension.js",
   "contributes": {
@@ -131,6 +133,7 @@
     "tree-sitter-java": "0.23.5",
     "tree-sitter-javascript": "0.21.4",
     "tree-sitter-python": "0.21.0",
+    "tree-sitter-rust": "0.21.0",
     "tree-sitter-typescript": "0.21.2"
   }
 }

samples/Test.rs

@@ -0,0 +1,80 @@
+// Sample Rust file for testing Code Metrics extension
+// This file demonstrates various Rust constructs that affect cognitive complexity.
+
+fn simple_function(x: i32) -> i32 {
+    x + 1
+}
+
+fn function_with_if(x: i32) -> i32 {
+    if x > 0 {
+        x
+    } else {
+        0
+    }
+}
+
+fn function_with_loop(n: i32) -> i32 {
+    let mut sum = 0;
+    for i in 0..n {
+        sum += i;
+    }
+    sum
+}
+
+fn function_with_match(x: i32) -> &'static str {
+    match x {
+        0 => "zero",
+        1..=9 => "single digit",
+        _ => "large",
+    }
+}
+
+fn complex_function(x: i32, y: i32) -> i32 {
+    if x > 0 && y > 0 {
+        for i in 0..x {
+            if i % 2 == 0 || i == y {
+                return i;
+            }
+        }
+    } else if x < 0 {
+        let mut n = x;
+        while n < 0 {
+            n += 1;
+        }
+        return n;
+    }
+    0
+}
+
+struct Calculator {
+    value: i32,
+}
+
+impl Calculator {
+    fn new(value: i32) -> Self {
+        Calculator { value }
+    }
+
+    fn apply(&self, op: &str, operand: i32) -> i32 {
+        match op {
+            "add" => self.value + operand,
+            "sub" => self.value - operand,
+            "mul" => self.value * operand,
+            _ => self.value,
+        }
+    }
+
+    fn compute_series(&self, n: i32) -> i32 {
+        let mut result = self.value;
+        for i in 1..=n {
+            if i % 3 == 0 && i % 5 == 0 {
+                result += 15;
+            } else if i % 3 == 0 {
+                result += 3;
+            } else if i % 5 == 0 {
+                result += 5;
+            }
+        }
+        result
+    }
+}