feat: dagrunner, initial version

src/error/tests.rs

@@ -0,0 +1,129 @@
+//! Unit tests for error module
+
+use crate::error::{DagError, DagResult};
+
+#[test]
+fn test_dag_error_display_invalid_dependency() {
+    // Test lines 47-54 in error.rs
+    let err = DagError::InvalidDependency { task_id: 42 };
+    let display = format!("{}", err);
+
+    assert!(display.contains("Invalid dependency"));
+    assert!(display.contains("task #42"));
+    assert!(display.contains("does not exist"));
+    assert!(display.contains("Ensure all task handles"));
+}
+
+#[test]
+fn test_dag_error_display_type_mismatch() {
+    // Test lines 56-65 in error.rs
+    let err = DagError::TypeMismatch {
+        expected: "i32",
+        found: "String",
+    };
+    let display = format!("{}", err);
+
+    assert!(display.contains("Type mismatch"));
+    assert!(display.contains("Expected: i32"));
+    assert!(display.contains("Found: String"));
+    assert!(display.contains("Verify that dependency types"));
+}
+
+#[test]
+fn test_dag_error_display_task_panicked() {
+    // Test lines 67-77 in error.rs
+    let err = DagError::TaskPanicked {
+        task_id: 99,
+        panic_message: "assertion failed".to_string(),
+    };
+    let display = format!("{}", err);
+
+    assert!(display.contains("Task #99 panicked"));
+    assert!(display.contains("assertion failed"));
+    assert!(display.contains("indicating a bug"));
+    assert!(display.contains("entire DAG execution is aborted"));
+}
+
+#[test]
+fn test_dag_error_display_cycle_detected() {
+    let err = DagError::CycleDetected {
+        nodes: vec![1, 2, 3, 1],
+        description: "A->B->C->A".to_string(),
+    };
+    let display = format!("{}", err);
+
+    assert!(display.contains("Cycle detected"));
+    assert!(display.contains("A->B->C->A"));
+    assert!(display.contains("[1, 2, 3, 1]"));
+    assert!(display.contains("cannot have cycles"));
+}
+
+#[test]
+fn test_dag_error_display_result_not_found() {
+    let err = DagError::ResultNotFound { task_id: 7 };
+    let display = format!("{}", err);
+
+    assert!(display.contains("Result not found"));
+    assert!(display.contains("task #7"));
+    assert!(display.contains("Call dag.run()"));
+}
+
+#[test]
+fn test_dag_error_std_error_impl() {
+    // Test that DagError implements std::error::Error
+    let err = DagError::InvalidDependency { task_id: 1 };
+    let err_ref: &dyn std::error::Error = &err;
+
+    // Should be able to call Error trait methods
+    let _ = err_ref.to_string();
+    assert!(err_ref.source().is_none()); // DagError doesn't chain errors
+}
+
+#[test]
+fn test_dag_error_equality() {
+    let err1 = DagError::InvalidDependency { task_id: 42 };
+    let err2 = DagError::InvalidDependency { task_id: 42 };
+    let err3 = DagError::InvalidDependency { task_id: 99 };
+
+    assert_eq!(err1, err2);
+    assert_ne!(err1, err3);
+}
+
+#[test]
+fn test_dag_error_clone() {
+    let err = DagError::TaskPanicked {
+        task_id: 10,
+        panic_message: "test panic".to_string(),
+    };
+
+    let cloned = err.clone();
+    assert_eq!(err, cloned);
+}
+
+#[test]
+fn test_dag_error_debug() {
+    let err = DagError::TypeMismatch {
+        expected: "i32",
+        found: "bool",
+    };
+
+    let debug_str = format!("{:?}", err);
+    assert!(debug_str.contains("TypeMismatch"));
+    assert!(debug_str.contains("expected"));
+    assert!(debug_str.contains("found"));
+}
+
+#[test]
+fn test_dag_result_type_alias() {
+    // Test that DagResult works as expected
+    fn returns_dag_result() -> DagResult<i32> {
+        Ok(42)
+    }
+
+    fn returns_dag_error() -> DagResult<String> {
+        Err(DagError::ResultNotFound { task_id: 1 })
+    }
+
+    assert!(returns_dag_result().is_ok());
+    assert!(returns_dag_error().is_err());
+}