Merge pull request #135 from tonybaloney/optional

Implement Optional[T] with a default of None as a nullable type of T.
tonybaloney · Aug 19, 2024 · acd6e72 · acd6e72
2 parents 04e5adc + 752fda7
commit acd6e72
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diff --git a/docs/reference.md b/docs/reference.md
@@ -18,6 +18,7 @@ CSnakes supports the following typed scenarios:
 | `typing.Dict[K, V]`    | `IReadOnlyDictionary<K, V>` |
 | `typing.Mapping[K, V]` | `IReadOnlyDictionary<K, V>` |
 | `typing.Tuple[T1, T2, ...]` | `(T1, T2, ...)` |
+| `typing.Optional[T]`   | `T?`              |
 | `None` (Return)        | `void`            |
 
 

diff --git a/src/CSnakes.Tests/GeneratedSignatureTests.cs b/src/CSnakes.Tests/GeneratedSignatureTests.cs
@@ -34,6 +34,7 @@ public class GeneratedSignatureTests(TestEnvironment testEnv) : IClassFixture<Te
     [InlineData("def hello(a: int = 0xdeadbeef) -> None:\n ...\n", "void Hello(long a = 0xDEADBEEF)")]
     [InlineData("def hello(a: int = 0b10101010) -> None:\n ...\n", "void Hello(long a = 0b10101010)")]
     [InlineData("def hello(a: int = 2147483648) -> None:\n ...\n", "void Hello(long a = 2147483648L)")]
+    [InlineData("def hello(a: Optional[int] = None) -> None:\n ...\n", "void Hello(long? a = null)")]
     public void TestGeneratedSignature(string code, string expected)
     {
 

diff --git a/src/CSnakes/Reflection/TypeReflection.cs b/src/CSnakes/Reflection/TypeReflection.cs
@@ -23,6 +23,7 @@ public static TypeSyntax AsPredefinedType(PythonTypeSpec pythonType)
                 "Dict" => CreateDictionaryType(pythonType.Arguments[0], pythonType.Arguments[1]),
                 "Mapping" => CreateDictionaryType(pythonType.Arguments[0], pythonType.Arguments[1]),
                 "Sequence" => CreateListType(pythonType.Arguments[0]),
+                "Optional" => AsPredefinedType(pythonType.Arguments[0]),
                 // Todo more types... see https://docs.python.org/3/library/stdtypes.html#standard-generic-classes
                 _ => SyntaxFactory.ParseTypeName("PyObject"),// TODO : Should be nullable?
             };

diff --git a/src/Integration.Tests/DefaultsTests.cs b/src/Integration.Tests/DefaultsTests.cs
@@ -20,5 +20,33 @@ public void TestDefault_FloatArg()
     {
         var testDefaults = Env.TestDefaults();
         Assert.Equal(-1, testDefaults.TestDefaultFloatArg());
+    }
+
+    [Fact]
+    public void TestDefault_OptionalInt()
+    {
+        var testDefaults = Env.TestDefaults();
+        Assert.True(testDefaults.TestOptionalInt());
+    }
+
+    [Fact]
+    public void TestDefault_OptionalStr()
+    {
+        var testDefaults = Env.TestDefaults();
+        Assert.True(testDefaults.TestOptionalStr());
+    }
+
+    [Fact]
+    public void TestDefault_OptionalList()
+    {
+        var testDefaults = Env.TestDefaults();
+        Assert.True(testDefaults.TestOptionalList());
+    }
+
+    [Fact]
+    public void TestDefault_OptionalAny()
+    {
+        var testDefaults = Env.TestDefaults();
+        Assert.True(testDefaults.TestOptionalAny());
     }
 }
diff --git a/src/Integration.Tests/python/test_defaults.py b/src/Integration.Tests/python/test_defaults.py
@@ -1,3 +1,5 @@
+from typing import Any, Optional
+
 def test_default_str_arg(a: str = "hello") -> str:
     return a
 
@@ -9,3 +11,18 @@ def test_default_float_arg(a: float = -1) -> float:
 
 def test_int_literals(a: int = 0x1337, b: int = 0b10101011) -> int:
     return a
+
+def test_optional_int(a: Optional[int] = None) -> bool:
+    return a is None
+
+
+def test_optional_str(a: Optional[str] = None) -> bool:
+    return a is None
+
+
+def test_optional_list(a: Optional[list[int]] = None) -> bool:
+    return a is None
+
+
+def test_optional_any(a: Optional[Any] = None) -> bool:
+    return a is None