Add support for Rocket forms

Cargo.toml

@@ -28,6 +28,7 @@ bytes = { default-features = false, optional = true, version = "1.0" }
 diesel = { default-features = false, features = ["postgres"], optional = true, version = "1.4" }
 num-traits = { default-features = false, features = ["i128"], version = "0.2" }
 postgres = { default-features = false, optional = true, version = "0.19" }
+rocket = { default-features = false, optional = true, version = "0.5.0-rc.1" }
 serde = { default-features = false, optional = true, version = "1.0" }
 serde_json = { default-features = false, optional = true, version = "1.0" }
 tokio-postgres = { default-features = false, optional = true, version = "0.7" }
@@ -51,6 +52,7 @@ default = ["serde", "std"]
 legacy-ops = []
 maths = []
 maths-nopanic = ["maths"]
+rocket-traits = ["rocket"]
 rust-fuzz = ["arbitrary"]
 serde-arbitrary-precision = ["serde", "serde_json/arbitrary_precision"]
 serde-bincode = ["serde-str"] # Backwards compatability

Makefile.toml

@@ -116,6 +116,7 @@ dependencies = [
     "test-maths",
     "test-misc",
     "test-db",
+    "test-rocket-traits",
     "test-serde",
     "test-macros"
 ]
@@ -186,6 +187,10 @@ args = ["test", "--workspace", "--tests", "--features=db-tokio-postgres", "db",
 command = "cargo"
 args = ["test", "--workspace", "--tests", "--features=db-diesel-postgres", "db", "--", "--skip", "generated"]
 
+[tasks.test-rocket-traits]
+command = "cargo"
+args = ["test", "--workspace", "--features=rocket-traits"]
+
 [tasks.test-serde-float]
 command = "cargo"
 args = ["test", "--workspace", "--tests", "--features=serde-float", "serde", "--", "--skip", "generated"]

README.md

@@ -79,6 +79,7 @@ assert_eq!(total.to_string(), "27.26");
 * [db-diesel-postgres](#db-diesel-postgres)
 * [legacy-ops](#legacy-ops)
 * [maths](#maths)
+* [rocket-traits](#rocket-traits)
 * [rust-fuzz](#rust-fuzz)
 * [serde-float](#serde-float)
 * [serde-str](#serde-str)
@@ -117,6 +118,10 @@ Please note that `ln` and `log10` will panic on invalid input with `checked_ln`
 to curb against this. When the `maths` feature was first developed the library would return `0` on invalid input. To re-enable this 
 non-panicking behavior, please use the feature: `maths-nopanic`. 
 
+### `rocket-traits`
+
+Enable support for Rocket forms by implementing the `FromFormField` trait.
+
 ### `rust-fuzz`
 
 Enable `rust-fuzz` support by implementing the `Arbitrary` trait.
@@ -164,4 +169,4 @@ Please refer to the [Build document](BUILD.md) for more information on building
 
 This library maintains support for rust compiler versions at least one year old and only updates the minimum version if and
 when required. The current minimum compiler version is [`1.46.0`](https://github.com/rust-lang/rust/blob/master/RELEASES.md#version-1460-2020-08-27) 
-which was released on `2020-08-27`.
+which was released on `2020-08-27`.

src/lib.rs

@@ -79,6 +79,7 @@
 //! * [db-diesel-postgres](#db-diesel-postgres)
 //! * [legacy-ops](#legacy-ops)
 //! * [maths](#maths)
+//! * [rocket-traits](#rocket-traits)
 //! * [rust-fuzz](#rust-fuzz)
 //! * [serde-float](#serde-float)
 //! * [serde-str](#serde-str)
@@ -111,12 +112,16 @@
 //!
 //! The `maths` feature enables additional complex mathematical functions such as `pow`, `ln`, `enf`, `exp` etc.
 //! Documentation detailing the additional functions can be found on the
-//! [`MathematicalOps`](https://docs.rs/rust_decimal/latest/rust_decimal/trait.MathematicalOps.html) trait.  
+//! [`MathematicalOps`](https://docs.rs/rust_decimal/latest/rust_decimal/trait.MathematicalOps.html) trait.
 //!
 //! Please note that `ln` and `log10` will panic on invalid input with `checked_ln` and `checked_log10` the preferred functions
 //! to curb against this. When the `maths` feature was first developed the library would return `0` on invalid input. To re-enable this
 //! non-panicing behavior, please use the feature: `maths-nopanic`.
 //!
+//! ### `rocket-traits`
+//!
+//! Enable support for forms by implementing the `FromFormField` trait.
+//!
 //! ### `rust-fuzz`
 //!
 //! Enable `rust-fuzz` support by implementing the `Arbitrary` trait.
@@ -176,6 +181,8 @@ mod db;
 mod fuzz;
 #[cfg(feature = "maths")]
 mod maths;
+#[cfg(feature = "rocket-traits")]
+mod rocket;
 #[cfg(feature = "serde")]
 mod serde;
 

src/rocket.rs

@@ -0,0 +1,12 @@
+use crate::Decimal;
+use rocket::form::{self, FromFormField, ValueField};
+use std::str::FromStr;
+
+impl<'v> FromFormField<'v> for Decimal {
+    fn default() -> Option<Self> {
+        None
+    }
+    fn from_value(field: ValueField<'v>) -> form::Result<'v, Self> {
+        Decimal::from_str(field.value).map_err(|_| form::Error::validation("not a valid number").into())
+    }
+}

tests/decimal_tests.rs

@@ -4304,6 +4304,29 @@ mod generated {
     gen_test!(test_sub_111_111, "Sub_111_111.csv", checked_sub);
 }
 
+#[cfg(feature = "rocket-traits")]
+mod rocket {
+    use crate::Decimal;
+    use rocket::form::{Form, FromForm};
+    use std::str::FromStr;
+
+    #[derive(FromForm)]
+    struct Example {
+        foo: Decimal,
+        bar: Decimal,
+    }
+
+    #[test]
+    fn it_can_parse_form() {
+        let parsed: Example = Form::parse("bar=0.12345678901234567890123456789&foo=-123456.78").unwrap();
+        assert_eq!(parsed.foo, Decimal::from_str("-123456.78").unwrap());
+        assert_eq!(
+            parsed.bar,
+            Decimal::from_str("0.12345678901234567890123456789").unwrap()
+        );
+    }
+}
+
 #[cfg(feature = "rust-fuzz")]
 mod rust_fuzz {
     use arbitrary::{Arbitrary, Unstructured};