From 13ac3f947f089c037873b9bddf36245c1d663b9d Mon Sep 17 00:00:00 2001
From: Andrew Walbran <qwandor@google.com>
Date: Mon, 25 Mar 2024 20:47:47 +0000
Subject: [PATCH 1/3] Derive Hash for Code.

---
 src/lib.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/lib.rs b/src/lib.rs
index 6ae4e10..10d0ed0 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -27,7 +27,7 @@ pub enum Error {
 }
 
 /// A decoded RF button code.
-#[derive(Clone, Eq, PartialEq)]
+#[derive(Clone, Eq, Hash, PartialEq)]
 pub struct Code {
     /// The decoded value.
     pub value: u32,

From f3ab99016d69120d825942f3d8c80c0b84f6d9bc Mon Sep 17 00:00:00 2001
From: Andrew Walbran <qwandor@google.com>
Date: Mon, 25 Mar 2024 20:48:05 +0000
Subject: [PATCH 2/3] Implement serde traits for Code.

---
 CHANGELOG.md |  8 ++++++
 Cargo.toml   |  6 ++++
 src/lib.rs   | 80 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 94 insertions(+)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index e990334..5560cf7 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,13 @@
 # Changelog
 
+## Unreleased
+
+### New features
+
+- Implemented `Hash` for `Code`.
+- Implemented `serde::Serialize` and `serde::Deserialize` for `Code`, behind new `serde` feature
+  flag.
+
 ## 0.1.0
 
 Initial release.
diff --git a/Cargo.toml b/Cargo.toml
index 7ae5511..caa7070 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -11,6 +11,7 @@ categories = ["hardware-support", "parser-implementations"]
 
 [dependencies]
 thiserror = "1.0.30"
+serde = { version = "1.0.197", optional = true }
 
 [dev-dependencies]
 cc1101 = { version = "0.1.3", features = ["std"] }
@@ -21,3 +22,8 @@ eyre = "0.6.9"
 log = "0.4.20"
 pretty_env_logger = "0.5.0"
 rppal = { version = "0.17.1", features = ["hal"] }
+serde_test = "1.0.176"
+
+[features]
+default = ["serde"]
+serde = ["dep:serde"]
diff --git a/src/lib.rs b/src/lib.rs
index 10d0ed0..d959379 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -45,6 +45,44 @@ impl Debug for Code {
     }
 }
 
+#[cfg(feature = "serde")]
+impl<'de> serde::Deserialize<'de> for Code {
+    fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
+    where
+        D: serde::Deserializer<'de>,
+    {
+        let s = String::deserialize(deserializer)?;
+        if s.len() > 8 {
+            return Err(serde::de::Error::invalid_value(
+                serde::de::Unexpected::Str(&s),
+                &"no more than 8 characters",
+            ));
+        }
+        let value =
+            u32::from_str_radix(&s, 16).map_err(|e| serde::de::Error::custom(e.to_string()))?;
+        Ok(Self {
+            value,
+            length: s.len() as u8 * 4,
+        })
+    }
+}
+
+#[cfg(feature = "serde")]
+impl serde::Serialize for Code {
+    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+    where
+        S: serde::Serializer,
+    {
+        if self.length % 4 != 0 {
+            return Err(serde::ser::Error::custom(
+                "Only codes with length a multiple of 4 can be serialized.",
+            ));
+        }
+        let s = format!("{:01$x}", self.value, usize::from(self.length) / 4);
+        serializer.serialize_str(&s)
+    }
+}
+
 /// Given a sequence of pulse durations in microseconds (starting with a high pulse), try to decode
 /// a button code.
 pub fn decode(pulses: &[u16]) -> Result<Code, Error> {
@@ -153,4 +191,46 @@ mod tests {
             })
         );
     }
+
+    #[cfg(feature = "serde")]
+    #[test]
+    fn serde_code() {
+        use serde_test::{assert_tokens, Token};
+
+        assert_tokens(
+            &Code {
+                value: 0,
+                length: 12,
+            },
+            &[Token::Str("000")],
+        );
+        assert_tokens(
+            &Code {
+                value: 0xf,
+                length: 4,
+            },
+            &[Token::Str("f")],
+        );
+        assert_tokens(
+            &Code {
+                value: 0x123456,
+                length: 24,
+            },
+            &[Token::Str("123456")],
+        );
+        assert_tokens(
+            &Code {
+                value: 0xabcdef,
+                length: 24,
+            },
+            &[Token::Str("abcdef")],
+        );
+        assert_tokens(
+            &Code {
+                value: 0xff112233,
+                length: 32,
+            },
+            &[Token::Str("ff112233")],
+        );
+    }
 }

From a4979344645630c6873d544d3e597239bb5810b1 Mon Sep 17 00:00:00 2001
From: Andrew Walbran <qwandor@google.com>
Date: Mon, 25 Mar 2024 20:51:27 +0000
Subject: [PATCH 3/3] Build and test with no features too.

---
 .github/workflows/rust.yml | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/.github/workflows/rust.yml b/.github/workflows/rust.yml
index 96c81c8..21a364c 100644
--- a/.github/workflows/rust.yml
+++ b/.github/workflows/rust.yml
@@ -14,10 +14,14 @@ jobs:
 
     steps:
       - uses: actions/checkout@v4
-      - name: Build
+      - name: Build with all features
         run: cargo build --all-features
-      - name: Run tests
+      - name: Run tests with all features
         run: cargo test --all-features
+      - name: Build with no features
+        run: cargo build --no-default-features
+      - name: Run tests with no features
+        run: cargo test --no-default-features
       - name: Run clippy
         uses: actions-rs/clippy-check@v1
         with: