Fixed ron-rs#367 with eager implicit some

CHANGELOG.md

@@ -22,6 +22,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Bump MSRV to 1.46.0 ([#361](https://github.com/ron-rs/ron/pull/361))
 - Fix issue [#337](https://github.com/ron-rs/ron/issues/337) by removing `decimal_floats` PrettyConfig option and unconditional decimals in floats ([#363](https://github.com/ron-rs/ron/pull/363))
 - Fix issue [#203](https://github.com/ron-rs/ron/issues/203) with full de error positioning ([#356](https://github.com/ron-rs/ron/pull/356))
+- Fix issue [#367](https://github.com/ron-rs/ron/issues/367) with eager implicit some ([#368](https://github.com/ron-rs/ron/pull/368))
 
 ## [0.7.0] - 2021-10-22
 

docs/extensions.md

@@ -42,7 +42,7 @@ You can add this extension by adding the following attribute at the top of your
 
 `#![enable(implicit_some)]`
 
-This feature enables RON to automatically convert any value to `Some(value)` if the deserialized struct requires it.
+This feature enables RON to automatically convert any value to `Some(value)` if the deserialized type requires it.
 
 ```rust
 struct Object {
@@ -66,6 +66,15 @@ Enabling the feature would automatically infer `Some(x)` if `x` is given. In thi
 )
 ```
 
+With this extension enabled, explicitly given `None` and `Some(..)` will be matched eagerly on `Option<Option<Option<u32>>>`, i.e.
+* `5` -> `Some(Some(Some(5)))`
+* `None` -> `None`
+* `Some(5)` -> `Some(Some(Some(5)))`
+* `Some(None)` -> `Some(None)`
+* `Some(Some(5))` -> `Some(Some(Some(5)))`
+* `Some(Some(None))` -> `Some(Some(None))`
+* `Some(Some(Some(5)))` -> `Some(Some(Some(5)))`
+
 # unwrap_variant_newtypes
 
 You can add this extension by adding the following attribute at the top of your RON document:

src/de/mod.rs

@@ -349,8 +349,6 @@ impl<'de, 'a> de::Deserializer<'de> for &'a mut Deserializer<'de> {
     {
         if self.bytes.consume("None") {
             visitor.visit_none()
-        } else if self.bytes.exts.contains(Extensions::IMPLICIT_SOME) {
-            visitor.visit_some(&mut *self)
         } else if self.bytes.consume("Some") && {
             self.bytes.skip_ws()?;
             self.bytes.consume("(")
@@ -366,6 +364,8 @@ impl<'de, 'a> de::Deserializer<'de> for &'a mut Deserializer<'de> {
             } else {
                 Err(Error::ExpectedOptionEnd)
             }
+        } else if self.bytes.exts.contains(Extensions::IMPLICIT_SOME) {
+            visitor.visit_some(&mut *self)
         } else {
             Err(Error::ExpectedOption)
         }

tests/367_implicit_some.rs

@@ -0,0 +1,108 @@
+#[derive(Debug, PartialEq, serde::Deserialize, serde::Serialize)]
+struct MaybeFields {
+    f1: i64,
+    f2: Option<i64>,
+    f3: Option<Option<i64>>,
+}
+
+#[test]
+fn test_recursive_implicit_some() {
+    // Test case provided by d86leader in
+    //  https://github.com/ron-rs/ron/issues/367#issue-1147920589
+
+    let x1: std::result::Result<MaybeFields, _> =
+        ron::from_str("#![enable(implicit_some)]\n(f1: 1)");
+    let x2: std::result::Result<MaybeFields, _> =
+        ron::from_str("#![enable(implicit_some)]\n(f1: 1, f2: None, f3: None)");
+    let x3: std::result::Result<MaybeFields, _> =
+        ron::from_str("#![enable(implicit_some)]\n(f1: 1, f2: 2, f3: 3)");
+    let x4: std::result::Result<MaybeFields, _> =
+        ron::from_str("#![enable(implicit_some)]\n(f1: 1, f2: 2, f3: Some(3))");
+    let x5: std::result::Result<MaybeFields, _> =
+        ron::from_str("#![enable(implicit_some)]\n(f1: 1, f2: 2, f3: Some(Some(3)))");
+    let x6: std::result::Result<MaybeFields, _> =
+        ron::from_str("#![enable(implicit_some)]\n(f1: 1, f2: 2, f3: Some(None))");
+
+    assert_eq!(
+        x1,
+        Ok(MaybeFields {
+            f1: 1,
+            f2: None,
+            f3: None
+        })
+    );
+    assert_eq!(
+        x2,
+        Ok(MaybeFields {
+            f1: 1,
+            f2: None,
+            f3: None
+        })
+    );
+    assert_eq!(
+        x3,
+        Ok(MaybeFields {
+            f1: 1,
+            f2: Some(2),
+            f3: Some(Some(3))
+        })
+    );
+    assert_eq!(
+        x4,
+        Ok(MaybeFields {
+            f1: 1,
+            f2: Some(2),
+            f3: Some(Some(3))
+        })
+    );
+    assert_eq!(
+        x5,
+        Ok(MaybeFields {
+            f1: 1,
+            f2: Some(2),
+            f3: Some(Some(3))
+        })
+    );
+    assert_eq!(
+        x6,
+        Ok(MaybeFields {
+            f1: 1,
+            f2: Some(2),
+            f3: Some(None)
+        })
+    );
+}
+
+#[test]
+fn test_nested_implicit_some() {
+    assert_eq!(
+        ron::from_str::<Option<Option<Option<u32>>>>("#![enable(implicit_some)]\n5"),
+        Ok(Some(Some(Some(5))))
+    );
+    assert_eq!(
+        ron::from_str::<Option<Option<Option<u32>>>>("#![enable(implicit_some)]\nNone"),
+        Ok(None)
+    );
+    assert_eq!(
+        ron::from_str::<Option<Option<Option<u32>>>>("#![enable(implicit_some)]\nSome(5)"),
+        Ok(Some(Some(Some(5))))
+    );
+    assert_eq!(
+        ron::from_str::<Option<Option<Option<u32>>>>("#![enable(implicit_some)]\nSome(None)"),
+        Ok(Some(None))
+    );
+    assert_eq!(
+        ron::from_str::<Option<Option<Option<u32>>>>("#![enable(implicit_some)]\nSome(Some(5))"),
+        Ok(Some(Some(Some(5))))
+    );
+    assert_eq!(
+        ron::from_str::<Option<Option<Option<u32>>>>("#![enable(implicit_some)]\nSome(Some(None))"),
+        Ok(Some(Some(None)))
+    );
+    assert_eq!(
+        ron::from_str::<Option<Option<Option<u32>>>>(
+            "#![enable(implicit_some)]\nSome(Some(Some(5)))"
+        ),
+        Ok(Some(Some(Some(5))))
+    );
+}