feat(stdlib): add punycode encoding functions (#672)

* feat(stdlib): add punycode encoding functions

This adds `encode_punycode` and `decode_punycode` functions.
It also adds tests to confirm `parse_url` function behavior when it comes to punycode.

Fixes: #659

* Fix changelog entry PR reference

* Add tests and examples of fully ASCII strings to punycode functions

* Add benches for punycode related functions

* Add VRL tests for punycode encoding

* Make punycode functions fallible

* Rename `err` to `errors` in `map_err`

Cargo.toml

@@ -74,6 +74,7 @@ stdlib = [
  "dep:hex",
  "dep:hmac",
  "dep:hostname",
+ "dep:idna",
  "dep:indexmap",
  "dep:md-5",
  "dep:nom",
@@ -123,6 +124,7 @@ exitcode = {version = "1", optional = true }
 flate2 = { version = "1.0.28", default-features = false, features = ["default"], optional = true }
 hex = { version = "0.4", optional = true }
 hmac = { version = "0.12.1", optional = true }
+idna = { version = "0.5", optional = true }
 iana-time-zone = "0.1.59"
 indexmap = { version = "~2.2.2", default-features = false, features = ["std"], optional = true}
 indoc = {version = "2.0.4", optional = true }

benches/stdlib.rs

@@ -25,6 +25,7 @@ criterion_group!(
               decode_base16,
               decode_base64,
               decode_percent,
+              decode_punycode,
               decrypt,
               // TODO: Cannot pass a Path to bench_function
               //del,
@@ -35,6 +36,7 @@ criterion_group!(
               encode_json,
               encode_logfmt,
               encode_percent,
+              encode_punycode,
               encrypt,
               ends_with,
               // TODO: Cannot pass a Path to bench_function
@@ -301,6 +303,20 @@ bench_function! {
     }
 }
 
+bench_function! {
+    decode_punycode => vrl::stdlib::DecodePunycode;
+
+    encoded {
+        args: func_args![value: "www.xn--caf-dma.com"],
+        want: Ok("www.café.com"),
+    }
+
+    non_encoded {
+        args: func_args![value: "www.cafe.com"],
+        want: Ok("www.cafe.com"),
+    }
+}
+
 bench_function! {
     decode_mime_q => vrl::stdlib::DecodeMimeQ;
 
@@ -443,6 +459,20 @@ bench_function! {
     }
 }
 
+bench_function! {
+    encode_punycode => vrl::stdlib::EncodePunycode;
+
+    idn {
+        args: func_args![value: "www.CAFé.com"],
+        want: Ok("www.xn--caf-dma.com"),
+    }
+
+    ascii {
+        args: func_args![value: "www.cafe.com"],
+        want: Ok("www.cafe.com"),
+    }
+}
+
 bench_function! {
     ends_with => vrl::stdlib::EndsWith;
 

changelog.d/672.feature.md

@@ -0,0 +1 @@
+Added `encode_punycode` and `decode_punycode` functions

lib/tests/tests/functions/punycode/decode.vrl

@@ -0,0 +1,3 @@
+# result: "www.porquénopuedensimplementehablarenespañol.com"
+
+decode_punycode!("www.xn--PorqunopuedensimplementehablarenEspaol-fmd56a.com")

lib/tests/tests/functions/punycode/encode.vrl

@@ -0,0 +1,3 @@
+# result: "www.xn--ihqwcrb4cv8a8dqg056pqjye.com"
+
+encode_punycode!("www.他们为什么不说中文.com")

lib/tests/tests/functions/punycode/encode_decode.vrl

@@ -0,0 +1,5 @@
+# object: { "host": "www.ليهمابتكلموشعربي؟.他们为什么不说中文" }
+# result: "www.ليهمابتكلموشعربي؟.他们为什么不说中文"
+
+encoded = encode_punycode!(.host)
+decode_punycode!(encoded)

lib/tests/tests/functions/punycode/url_encode_decode.vrl

@@ -0,0 +1,12 @@
+# object: { "url": "https://www.CAFé.com" }
+# result: { "host": "www.xn--caf-dma.com", "host_decoded": "www.café.com" }
+
+# parse url
+parsed_url = parse_url!(.url)
+
+# delete url - no longer needed
+del(.url)
+
+.host = parsed_url.host
+.host_decoded = decode_punycode!(.host)
+.

src/stdlib/decode_punycode.rs

@@ -0,0 +1,87 @@
+use crate::compiler::prelude::*;
+
+#[derive(Clone, Copy, Debug)]
+pub struct DecodePunycode;
+
+impl Function for DecodePunycode {
+    fn identifier(&self) -> &'static str {
+        "decode_punycode"
+    }
+
+    fn parameters(&self) -> &'static [Parameter] {
+        &[Parameter {
+            keyword: "value",
+            kind: kind::BYTES,
+            required: true,
+        }]
+    }
+
+    fn compile(
+        &self,
+        _state: &state::TypeState,
+        _ctx: &mut FunctionCompileContext,
+        arguments: ArgumentList,
+    ) -> Compiled {
+        let value = arguments.required("value");
+
+        Ok(DecodePunycodeFn { value }.as_expr())
+    }
+
+    fn examples(&self) -> &'static [Example] {
+        &[
+            Example {
+                title: "punycode string",
+                source: r#"decode_punycode!("www.xn--caf-dma.com")"#,
+                result: Ok("www.café.com"),
+            },
+            Example {
+                title: "ascii string",
+                source: r#"decode_punycode!("www.cafe.com")"#,
+                result: Ok("www.cafe.com"),
+            },
+        ]
+    }
+}
+
+#[derive(Clone, Debug)]
+struct DecodePunycodeFn {
+    value: Box<dyn Expression>,
+}
+
+impl FunctionExpression for DecodePunycodeFn {
+    fn resolve(&self, ctx: &mut Context) -> Resolved {
+        let value = self.value.resolve(ctx)?;
+        let string = value.try_bytes_utf8_lossy()?;
+
+        let (encoded, result) = idna::domain_to_unicode(&string);
+        result.map_err(|errors| format!("unable to decode punycode: {errors}"))?;
+
+        Ok(encoded.into())
+    }
+
+    fn type_def(&self, _: &state::TypeState) -> TypeDef {
+        TypeDef::bytes().fallible()
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use super::*;
+    use crate::value;
+
+    test_function![
+        decode_punycode => DecodePunycode;
+
+        demo_string {
+            args: func_args![value: value!("www.xn--caf-dma.com")],
+            want: Ok(value!("www.café.com")),
+            tdef: TypeDef::bytes().fallible(),
+        }
+
+        ascii_string {
+            args: func_args![value: value!("www.cafe.com")],
+            want: Ok(value!("www.cafe.com")),
+            tdef: TypeDef::bytes().fallible(),
+        }
+    ];
+}

src/stdlib/encode_punycode.rs

@@ -0,0 +1,98 @@
+use crate::compiler::prelude::*;
+
+#[derive(Clone, Copy, Debug)]
+pub struct EncodePunycode;
+
+impl Function for EncodePunycode {
+    fn identifier(&self) -> &'static str {
+        "encode_punycode"
+    }
+
+    fn parameters(&self) -> &'static [Parameter] {
+        &[Parameter {
+            keyword: "value",
+            kind: kind::BYTES,
+            required: true,
+        }]
+    }
+
+    fn compile(
+        &self,
+        _state: &state::TypeState,
+        _ctx: &mut FunctionCompileContext,
+        arguments: ArgumentList,
+    ) -> Compiled {
+        let value = arguments.required("value");
+
+        Ok(EncodePunycodeFn { value }.as_expr())
+    }
+
+    fn examples(&self) -> &'static [Example] {
+        &[
+            Example {
+                title: "IDN string",
+                source: r#"encode_punycode!("www.café.com")"#,
+                result: Ok("www.xn--caf-dma.com"),
+            },
+            Example {
+                title: "mixed case string",
+                source: r#"encode_punycode!("www.CAFé.com")"#,
+                result: Ok("www.xn--caf-dma.com"),
+            },
+            Example {
+                title: "ascii string",
+                source: r#"encode_punycode!("www.cafe.com")"#,
+                result: Ok("www.cafe.com"),
+            },
+        ]
+    }
+}
+
+#[derive(Clone, Debug)]
+struct EncodePunycodeFn {
+    value: Box<dyn Expression>,
+}
+
+impl FunctionExpression for EncodePunycodeFn {
+    fn resolve(&self, ctx: &mut Context) -> Resolved {
+        let value = self.value.resolve(ctx)?;
+        let string = value.try_bytes_utf8_lossy()?;
+
+        let encoded = idna::domain_to_ascii(&string)
+            .map_err(|errors| format!("unable to encode to punycode: {errors}"))?;
+
+        Ok(encoded.into())
+    }
+
+    fn type_def(&self, _: &state::TypeState) -> TypeDef {
+        TypeDef::bytes().fallible()
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use super::*;
+    use crate::value;
+
+    test_function![
+        encode_punycode => EncodePunycode;
+
+        idn_string {
+            args: func_args![value: value!("www.café.com")],
+            want: Ok(value!("www.xn--caf-dma.com")),
+            tdef: TypeDef::bytes().fallible(),
+        }
+
+        mixed_case {
+            args: func_args![value: value!("www.CAFé.com")],
+            want: Ok(value!("www.xn--caf-dma.com")),
+            tdef: TypeDef::bytes().fallible(),
+        }
+
+        ascii_string {
+            args: func_args![value: value!("www.cafe.com")],
+            want: Ok(value!("www.cafe.com")),
+            tdef: TypeDef::bytes().fallible(),
+        }
+    ];
+}

src/stdlib/mod.rs

@@ -53,6 +53,7 @@ cfg_if::cfg_if! {
         mod decode_gzip;
         mod decode_mime_q;
         mod decode_percent;
+        mod decode_punycode;
         mod decode_snappy;
         mod decode_zlib;
         mod decode_zstd;
@@ -66,6 +67,7 @@ cfg_if::cfg_if! {
         mod encode_key_value;
         mod encode_logfmt;
         mod encode_percent;
+        mod encode_punycode;
         mod encode_snappy;
         mod encode_zlib;
         mod encode_zstd;
@@ -220,6 +222,7 @@ cfg_if::cfg_if! {
         pub use decode_gzip::DecodeGzip;
         pub use decode_mime_q::DecodeMimeQ;
         pub use decode_percent::DecodePercent;
+        pub use decode_punycode::DecodePunycode;
         pub use decode_snappy::DecodeSnappy;
         pub use decode_zlib::DecodeZlib;
         pub use decode_zstd::DecodeZstd;
@@ -233,6 +236,7 @@ cfg_if::cfg_if! {
         pub use encode_key_value::EncodeKeyValue;
         pub use encode_logfmt::EncodeLogfmt;
         pub use encode_percent::EncodePercent;
+        pub use encode_punycode::EncodePunycode;
         pub use encode_snappy::EncodeSnappy;
         pub use encode_zlib::EncodeZlib;
         pub use encode_zstd::EncodeZstd;
@@ -390,6 +394,7 @@ pub fn all() -> Vec<Box<dyn Function>> {
         Box::new(DecodeBase64),
         Box::new(DecodeGzip),
         Box::new(DecodePercent),
+        Box::new(DecodePunycode),
         Box::new(DecodeMimeQ),
         Box::new(DecodeSnappy),
         Box::new(DecodeZlib),
@@ -404,6 +409,7 @@ pub fn all() -> Vec<Box<dyn Function>> {
         Box::new(EncodeKeyValue),
         Box::new(EncodeLogfmt),
         Box::new(EncodePercent),
+        Box::new(EncodePunycode),
         Box::new(EncodeSnappy),
         Box::new(EncodeZlib),
         Box::new(EncodeZstd),

src/stdlib/parse_url.rs

@@ -208,5 +208,35 @@ mod tests {
             })),
             tdef: TypeDef::object(inner_kind()).fallible(),
         }
+
+        punycode {
+            args: func_args![value: value!("https://www.café.com")],
+            want: Ok(value!({
+                fragment: (),
+                host: "www.xn--caf-dma.com",
+                password: "",
+                path: "/",
+                port: (),
+                query: {},
+                scheme: "https",
+                username: "",
+            })),
+            tdef: TypeDef::object(inner_kind()).fallible(),
+        }
+
+        punycode_mixed_case {
+            args: func_args![value: value!("https://www.CAFé.com")],
+            want: Ok(value!({
+                fragment: (),
+                host: "www.xn--caf-dma.com",
+                password: "",
+                path: "/",
+                port: (),
+                query: {},
+                scheme: "https",
+                username: "",
+            })),
+            tdef: TypeDef::object(inner_kind()).fallible(),
+        }
     ];
 }