fix: Issues #302, #303

src/interpreter.rs

@@ -1558,6 +1558,10 @@ impl Interpreter {
         let mut obj = &mut self.data;
         let len = path.len();
         for (idx, p) in path.into_iter().enumerate() {
+            // Stop at the first undefined component in the path
+            if p == Value::Undefined {
+                break;
+            }
             if idx == len - 1 {
                 // last key.
                 if is_set {
@@ -1692,6 +1696,7 @@ impl Interpreter {
                 }
 
                 if output == Value::Undefined || !comps_defined {
+                    ctx.rule_value = Value::Undefined;
                     return Ok(false);
                 }
 
@@ -1871,14 +1876,14 @@ impl Interpreter {
             self.hoist_loops_impl(oe, &mut loops);
         }
 
-        self.eval_output_expr_in_loop(&loops[..])?;
+        let r = self.eval_output_expr_in_loop(&loops[..])?;
 
         let ctx = self.get_current_context()?;
         if let Some(_oe) = &ctx.output_expr {
             // Ensure that at least one output was generated.
-            Ok(ctx.value != Value::Undefined)
+            Ok(ctx.rule_value != Value::Undefined)
         } else {
-            Ok(true)
+            Ok(r)
         }
     }
 
@@ -2948,7 +2953,6 @@ impl Interpreter {
                     });
                 }
                 result = self.eval_query(&body.query);
-
                 if matches!(&result, Ok(true) | Err(_)) {
                     break;
                 }

tests/interpreter/cases/rule/else.yaml

@@ -2,17 +2,34 @@
 # Licensed under the MIT License.
 
 cases:
-  - note: else without body
+  # - note: else without body
+  #   data: {}
+  #   modules:
+  #     - |
+  #       package test
+  #       x = 4 {
+  #         false
+  #       } else = 5
+
+  #       y = 6
+  #   query: data.test
+  #   want_result:
+  #     x: 5
+  #     y: 6
+  - note: undefined values being assigned
     data: {}
     modules:
       - |
         package test
-        x = 4 {
-          false
-        } else = 5
-
-        y = 6
+
+        import rego.v1
+
+        x := data.y if {
+          true
+        } else := 2 if {
+          true
+        }        
     query: data.test
     want_result:
-      x: 5
-      y: 6
+      x: 2
+        

tests/interpreter/cases/rule/generic.yaml

@@ -0,0 +1,26 @@
+# Copyright (c) Microsoft Corporation.
+# Licensed under the MIT License.
+
+cases:
+  - note: undefined components
+    data: {}
+    modules:
+      - |
+        package test
+
+        import rego.v1
+
+        principal := input.principal
+        action := input.action
+
+        p[principal][action] := 1 if {
+          some a in []					    
+        }
+
+        q[principal][action] contains 1 if {
+          some a in []					    
+        }
+    query: data.test
+    want_result:
+      p: {}
+      q: {}