add Rules Engine to flows

2

@@ -0,0 +1,335 @@
+extern crate flow;
+use flow::eval;
+use flow::ExpressionEvaluator;
+use serde_json::json;
+use std::f64::consts;
+
+#[test]
+fn test_eval_function() {
+    let context = json!({
+        "x": 10,
+        "y": 5
+    });
+
+    assert_eq!(eval("x + y", &context), json!(15));
+    assert_eq!(eval("x * y", &context), json!(50));
+    assert_eq!(eval("x - y", &context), json!(5));
+    assert_eq!(eval("x / y", &context), json!(2));
+}
+
+#[test]
+fn test_expression_evaluator_error_handling() {
+    let context = json!({});
+    let mut evaluator = ExpressionEvaluator::new(&context);
+
+    let result = evaluator.eval("nonexistent.field");
+    assert!(
+        result.is_null() || result.is_string(),
+        "Expected null or error string for nonexistent field"
+    );
+
+    let result = evaluator.eval("1 +");
+    assert!(
+        result.is_null() || result.is_string(),
+        "Expected null or error string for invalid syntax"
+    );
+}
+
+#[test]
+#[should_panic(expected = "Division by zero")]
+fn test_expression_evaluator_division_by_zero() {
+    let context = json!({});
+    let mut evaluator = ExpressionEvaluator::new(&context);
+    // panic
+    assert_eq!(evaluator.eval("1 / 0"), "");
+}
+
+#[test]
+fn test_expression_evaluator() {
+    let context = json!({
+        "person": {
+            "name": "Alice",
+            "age": 30
+        },
+        "constants": {
+            "pi": consts::PI
+        }
+    });
+
+    let mut evaluator = ExpressionEvaluator::new(&context);
+
+    assert_eq!(evaluator.eval("person.name"), json!("Alice"));
+    assert_eq!(evaluator.eval("person.age + 5"), json!(35));
+    assert_eq!(evaluator.eval("constants.pi * 2"), json!(consts::TAU));
+}
+
+#[test]
+fn test_number_functions() {
+    let context = json!({});
+    let mut evaluator = ExpressionEvaluator::new(&context);
+
+    assert_eq!(evaluator.eval("abs(-1.23)"), json!(1.23));
+    assert!(evaluator.eval("rand(100)").as_u64().unwrap() <= 100);
+    assert_eq!(evaluator.eval("floor(5.9)"), json!(5));
+    assert_eq!(evaluator.eval("round(5.5)"), json!(6));
+    assert_eq!(evaluator.eval("ceil(5.1)"), json!(6));
+    assert_eq!(evaluator.eval("number('20')"), json!(20));
+    assert_eq!(evaluator.eval("isNumeric('20')"), json!(true));
+    assert_eq!(evaluator.eval("isNumeric('test')"), json!(false));
+}
+
+#[test]
+fn test_string_functions() {
+    let context = json!({});
+    let mut evaluator = ExpressionEvaluator::new(&context);
+
+    assert_eq!(evaluator.eval("len('string')"), json!(6));
+    assert_eq!(evaluator.eval("upper('string')"), json!("STRING"));
+    assert_eq!(evaluator.eval("lower('StrInG')"), json!("string"));
+    assert_eq!(
+        evaluator.eval("startsWith('Saturday night plans', 'Sat')"),
+        json!(true)
+    );
+    assert_eq!(
+        evaluator.eval("endsWith('Saturday night plans', 'plans')"),
+        json!(true)
+    );
+    assert_eq!(
+        evaluator.eval("contains('Saturday night plans', 'night')"),
+        json!(true)
+    );
+    assert_eq!(evaluator.eval("matches('12345', '^\\d+$')"), json!(true));
+    assert_eq!(
+        evaluator.eval("extract('2022-02-01', '(\\d{4})-(\\d{2})-(\\d{2})')"),
+        json!(["2022-02-01", "2022", "02", "01"])
+    );
+}
+
+#[test]
+fn test_complex_expressions() {
+    let context = json!({
+             "x": 10,
+            "y": 5,
+            "name": "John",
+            "price": 120
+    });
+    let mut evaluator = ExpressionEvaluator::new(&context);
+
+    assert_eq!(evaluator.eval("100 + 100"), json!(200));
+    assert_eq!(evaluator.eval("10 * 5"), json!(50));
+    assert_eq!(evaluator.eval("10 ^ 2"), json!(100));
+    assert_eq!(evaluator.eval("1 + 2 + 3"), json!(6));
+
+    assert_eq!(evaluator.eval("x + y"), json!(15));
+    assert_eq!(evaluator.eval("x * y"), json!(50));
+
+    assert_eq!(
+        evaluator.eval("\"hello\" + \" \" + \"world\""),
+        json!("hello world")
+    );
+    assert_eq!(evaluator.eval("len(\"world\")"), json!(5));
+    assert_eq!(evaluator.eval("upper(\"john\")"), json!("JOHN"));
+    assert_eq!(evaluator.eval("lower(\"HELLO\")"), json!("hello"));
+
+    assert_eq!(evaluator.eval("x > y"), json!(true));
+    assert_eq!(evaluator.eval("x <= 10"), json!(true));
+
+    assert_eq!(evaluator.eval("true and false"), json!(false));
+    assert_eq!(evaluator.eval("true or false"), json!(true));
+    assert_eq!(evaluator.eval("not false"), json!(true));
+
+    assert_eq!(evaluator.eval("5 > 3"), json!(true));
+    assert_eq!(evaluator.eval("10 <= 10"), json!(true));
+    assert_eq!(evaluator.eval("\"abc\" == \"abc\""), json!(true));
+
+    assert_eq!(evaluator.eval("true and false"), json!(false));
+    assert_eq!(evaluator.eval("true or false"), json!(true));
+    assert_eq!(evaluator.eval("not false"), json!(true));
+
+    assert_eq!(evaluator.eval("abs(-5)"), json!(5));
+    assert_eq!(evaluator.eval("round(3.7)"), json!(4));
+    assert_eq!(evaluator.eval("floor(3.7)"), json!(3));
+    assert_eq!(evaluator.eval("ceil(3.2)"), json!(4));
+
+    // Ternary
+    assert_eq!(
+        evaluator.eval("price > 100 ? 'premium' : 'value'"),
+        json!("premium")
+    );
+}
+
+#[test]
+fn test_unary_expressions() {
+    let context = json!({
+        "$": 5,
+        "currency": "USD"
+    });
+    let mut evaluator = ExpressionEvaluator::new(&context);
+
+    assert_eq!(evaluator.eval("$ == 5"), json!(true));
+    assert_eq!(evaluator.eval("$ >= 1"), json!(true));
+    assert_eq!(evaluator.eval("$ < 1"), json!(false));
+    assert_eq!(evaluator.eval("$ >= 0 and $ <= 10"), json!(true));
+    assert_eq!(evaluator.eval("$ > 0 and $ < 10"), json!(true));
+
+    let context = json!({ "$": "USD" });
+    let mut evaluator = ExpressionEvaluator::new(&context);
+
+    assert_eq!(evaluator.eval("$ == 'USD'"), json!(true));
+    assert_eq!(evaluator.eval("$ == 'EUR'"), json!(false));
+    assert_eq!(evaluator.eval("startsWith($, \"US\")"), json!(true));
+    assert_eq!(evaluator.eval("endsWith($, \"D\")"), json!(true));
+    assert_eq!(evaluator.eval("lower($) == \"usd\""), json!(true));
+}
+
+#[test]
+fn test_boolean_operations() {
+    let context = json!({
+        "a": true,
+        "b": false,
+        "x": 10,
+        "y": 5
+    });
+    let mut evaluator = ExpressionEvaluator::new(&context);
+
+    assert_eq!(evaluator.eval("a and b"), json!(false));
+    assert_eq!(evaluator.eval("a or b"), json!(true));
+    assert_eq!(evaluator.eval("!a"), json!(false));
+    assert_eq!(evaluator.eval("not(b)"), json!(true));
+
+    assert_eq!(evaluator.eval("a == true"), json!(true));
+    assert_eq!(evaluator.eval("b != true"), json!(true));
+
+    assert_eq!(evaluator.eval("(x > y) and (y < 10)"), json!(true));
+    assert_eq!(evaluator.eval("(x < y) or (x == 10)"), json!(true));
+
+    assert_eq!(evaluator.eval("bool('true')"), json!(true));
+    assert_eq!(evaluator.eval("bool('false')"), json!(false));
+}
+
+#[test]
+fn test_datatime_operations() {
+    let context = json!({});
+
+    let mut evaluator = ExpressionEvaluator::new(&context);
+
+    assert_eq!(evaluator.eval("date('2024-01-01')"), json!(1704067200));
+
+    assert_eq!(evaluator.eval("weekOfYear('2024-09-18')"), json!(38));
+
+    assert_eq!(
+        evaluator.eval("date('2024-04-04T21:48:30Z')"),
+        json!(1712267310)
+    );
+
+    assert_eq!(evaluator.eval("year('2024-09-18')"), json!(2024));
+    //
+    assert_eq!(evaluator.eval("time('21:49')"), json!(78540));
+
+    assert_eq!(evaluator.eval("time('21:48:20')"), json!(78500));
+
+    assert_eq!(evaluator.eval("duration('30m')"), json!(1800));
+    assert_eq!(evaluator.eval("duration('72h')"), json!(259200));
+
+    assert_eq!(evaluator.eval("dayOfMonth(date('2022-11-09'))"), json!(9));
+
+    assert_eq!(evaluator.eval("dayOfYear(date('2022-11-10'))"), json!(314));
+
+    assert_eq!(
+        evaluator.eval("weekdayString(date('2022-11-14'))"),
+        json!("Mon")
+    );
+
+    // https://github.com/gorules/zen/pull/91/files#diff-0351bd90a8ac5af79cbd69797085dae5d37782fb4359797dd72a801485f133a2R207
+    assert_eq!(
+        evaluator.eval("dateString(startOf('2024-01-01 00:00:00', 'day'))"),
+        json!("2024-01-01 00:00:00")
+    );
+}
+
+#[test]
+fn test_array_operations() {
+    let mut context = json!({
+        "code": 0,
+        "data": {
+            "array": [
+                1,
+                8,
+                9,
+                10,
+                30
+            ],
+            "map": {
+                "subMap": {
+                    "status": 1
+                }
+            }
+        }
+    });
+    //https://github.com/gorules/zen/blob/17b468f50755f448a298c60ff2af8eb1856fd0bb/core/expression/tests/data/standard.csv
+    let mut eveluator = ExpressionEvaluator::new(&context);
+    assert_eq!(eveluator.eval("len([1, 2, 3, 4, 5])"), json!(5));
+    assert_eq!(eveluator.eval("sum([1, 2, 3, 4, 5])"), json!(15));
+    assert_eq!(
+        eveluator.eval("map([1, 2, 3, 4, 5], # ^ 2)"),
+        json!([1, 4, 9, 16, 25])
+    );
+
+    assert_eq!(
+        eveluator.eval("filter([1, 2, 3, 4, 5], # > 3)"),
+        json!([4, 5])
+    );
+
+    assert_eq!(eval("filter(data.array,# > 9)", &context), json!([10, 30]));
+    assert_eq!(eval("data.map.subMap.status > 0", &context), json!(true));
+
+    let context = json!([
+        {
+            "id": "1",
+            "price": [
+                {
+                    "type": 1,
+                    "val": 2300
+                },
+                {
+                    "type": 2,
+                    "val": 1300
+                },
+                {
+                    "type": 3,
+                    "val": 4211
+                }
+            ],
+            "type": 1
+        },
+        {
+            "id": "2",
+            "price": [
+                {
+                    "type": 1,
+                    "val": 2300
+                },
+                {
+                    "type": 2,
+                    "val": 1300
+                },
+                {
+                    "type": 3,
+                    "val": 4211
+                }
+            ],
+            "type": 2
+        }
+    ]);
+    assert_eq!(eval("len([*])", &context), json!(2));
+    // assert_eq!(
+    //     eval("$[0].price[?(@.type == 3)].val", &context),
+    //     json!(4211)
+    // );
+    // assert_eq!(
+    //     eval("$[*].price[?(@.type == 3)].val", &context),
+    //     json!([4211, 4211])
+    // );
+    // assert_eq!(eval("$[0].id", &context), json!("1"));
+    // assert_eq!(eval("$[1].type", &context), json!(2));
+}