rust: avoid using unwrap()

Author: hrideshmg

checkers/rust/avoid_unwrap.test.rs

@@ -0,0 +1,27 @@
+fn test_antipattern() {
+    // These should be flagged
+    let some_option: Option<i32> = None;
+
+    // <expect-error>
+    let _ = some_option.unwrap();
+
+    let some_result: Result<i32, &str> = Err("Error occurred");
+
+    // <expect-error>
+    let _ = some_result.unwrap();
+
+    // <expect-error>
+    let _ = some_result.unwrap(); // Double check on another instance
+}
+
+fn test_safe() {}
+    // These are safe and should not be flagged
+
+    // Handling Option safely
+    let _ = some_option.unwrap_or(42); // Providing a default value
+
+    // some_option.unwrap();
+
+    // Should not flag string literals containing "unwrap"
+    let message = "Do not use unwrap in production!";
+}

checkers/rust/avoid_unwrap.yml

@@ -0,0 +1,27 @@
+language: rust
+name: avoid_unwrap
+message: "Using unwrap() may cause panics if the Option is None or the Result is Err, consider handling errors with match or expect()"
+category: antipattern
+severity: warning
+
+pattern: |
+  (
+    (call_expression
+      function: (field_expression
+        value: (_) @variable
+        field: (field_identifier) @method_name (#eq? @method_name "unwrap")
+      )
+      arguments: (arguments)
+    ) @avoid_unwrap
+  )
+
+exclude:
+  - "tests/**"
+  - "vendor/**"
+  - "**/test_*.rs"
+  - "**/*_test.rs"
+
+description: |
+  The use of .unwrap() in Rust can lead to unexpected panics if the value is None (for Option) or Err (for Result).
+  This can lead to crashes in production and make debugging harder. Consider handling errors explicitly with match
+  or use expect() if a panic is acceptable.