handle None values

Author: hardbyte

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "cel"
-version = "0.3.0"
+version = "0.3.1"
 edition = "2021"
 
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html

README.md

@@ -70,6 +70,13 @@ evaluate("is_adult(age)", context)
 ```
 
 
+## Testing
+
+```shell
+uv run pytest --log-cli-level=debug
+```
+
+
 ## Future work
 
 

pyproject.toml

@@ -1,6 +1,3 @@
-[build-system]
-requires = ["maturin>=1.5,<2.0"]
-build-backend = "maturin"
 
 [project]
 name = "common-expression-language"
@@ -14,11 +11,17 @@ dynamic = ["version"]
 dependencies = [
 ]
 
+[build-system]
+requires = ["maturin>=1.5,<2.0"]
+build-backend = "maturin"
+
+
 [tool.maturin]
 features = ["pyo3/extension-module"]
 
-[dependency-groups]
-dev = [
+[tool.uv]
+dev-dependencies = [
     "pytest>=8.3.3",
     "maturin>=1.7.4",
+    "pip>=24.3.1",
 ]

src/context.rs

@@ -25,7 +25,7 @@ impl Context {
             for (k, v) in variables {
                 let key = k
                     .extract::<String>()
-                    .map_err(|_| PyValueError::new_err("Keys must be strings"));
+                    .map_err(|_| PyValueError::new_err("Variable name must be strings"));
                 key.map(|key| context.add_variable(key, v))??;
             }
         };

src/lib.rs

@@ -7,7 +7,7 @@ use pyo3::exceptions::PyValueError;
 use pyo3::prelude::*;
 
 use chrono::{DateTime, Duration as ChronoDuration, Offset, TimeZone, Utc};
-use pyo3::types::{PyBytes, PyDateTime, PyDict, PyList, PyTuple};
+use pyo3::types::{PyBytes, PyDateTime, PyDict, PyList, PyNone, PyTuple};
 use pyo3::types::{PyDelta, PyFunction};
 use std::time::{Duration, SystemTime, UNIX_EPOCH};
 
@@ -98,7 +98,9 @@ impl TryIntoValue for RustyPyType<'_> {
     fn try_into_value(self) -> Result<Value, Self::Error> {
         let val = match self {
             RustyPyType(pyobject) => {
-                if let Ok(value) = pyobject.extract::<bool>() {
+                if pyobject.is_none() {
+                    Ok(Value::Null)
+                } else if let Ok(value) = pyobject.extract::<bool>() {
                     Ok(Value::Bool(value))
                 } else if let Ok(value) = pyobject.extract::<i64>() {
                     Ok(Value::Int(value))
@@ -140,7 +142,11 @@ impl TryIntoValue for RustyPyType<'_> {
                 } else if let Ok(value) = pyobject.downcast::<PyDict>() {
                     let mut map: HashMap<Key, Value> = HashMap::new();
                     for (key, value) in value.into_iter() {
-                        let key = if let Ok(k) = key.extract::<i64>() {
+                        let key = if key.is_none() {
+                            return Err(CelError::ConversionError(
+                                "None cannot be used as a key in dictionaries".to_string(),
+                            ));
+                        } else if let Ok(k) = key.extract::<i64>() {
                             Key::Int(k)
                         } else if let Ok(k) = key.extract::<u64>() {
                             Key::Uint(k)

tests/test_context.py

@@ -16,6 +16,10 @@ def test_context_vars_implicit():
     context = cel.Context({'a': 10})
     assert cel.evaluate("a", context) == 10
 
+def test_context_vars_none_value():
+    context = cel.Context({'a': None})
+    assert cel.evaluate("a", context) == None
+
 
 def test_adding_to_context():
     context = cel.Context()
@@ -73,3 +77,26 @@ def custom_function(a, b):
         'b': 2,
     })
     assert cel.evaluate("custom_function(a, b)", context) == 42
+
+def test_nested_context_none():
+
+    context = {
+        'spec': {
+            'type': 'dns',
+            'nameserver': None,
+            'host': 'github.com',
+            'timeout': 30.0,
+            'pattern': "\ndata['response-code'] == 'NOERROR' &&\nsize(data['A']) >= 1 && \n(timestamp(data["
+        },
+        'data': {
+            'canonical_name': 'github.com.',
+            'expiration': 1732097106.7902246,
+            'response': 'id 25\nopcode QUERY\nrcode NOERROR\nflags QR RD RA\nedns 0\npayload 65494\n;QUESTION\ng',
+            'A': ['4.237.22.38'],
+            'response-code': 'NOERROR',
+            'startTimestamp': '2024-11-20T10:04:59.789017+00:00',
+            'endTimestamp': '2024-11-20T10:04:59.790298+00:00'
+        }
+    }
+
+    context = cel.Context(variables=context)