units: Add standard_check fuzz test

diff --git a/.github/workflows/cron-daily-fuzz.yml b/.github/workflows/cron-daily-fuzz.yml
index f47c9f60..b0427b44 100644
--- a/.github/workflows/cron-daily-fuzz.yml
+++ b/.github/workflows/cron-daily-fuzz.yml
@@ -46,6 +46,7 @@ jobs:
           units_arbitrary_weight,
           units_parse_amount,
           units_parse_int,
+          units_standard_checks,
         ]
     steps:
       - name: Install test dependencies
diff --git a/Cargo-minimal.lock b/Cargo-minimal.lock
index 860f0dd3..ad208a2a 100644
--- a/Cargo-minimal.lock
+++ b/Cargo-minimal.lock
@@ -90,6 +90,7 @@ dependencies = [
  "honggfuzz",
  "serde",
  "serde_json",
+ "standard_test",
 ]
 
 [[package]]
@@ -443,6 +444,15 @@ dependencies = [
  "serde",
 ]
 
+[[package]]
+name = "standard_test"
+version = "0.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "af4bac6cd647192c3cb6e687af2703eb3a30e9187e555c664520cd848443ae70"
+dependencies = [
+ "arbitrary",
+]
+
 [[package]]
 name = "syn"
 version = "2.0.46"
diff --git a/Cargo-recent.lock b/Cargo-recent.lock
index bc02789a..90ebfb6b 100644
--- a/Cargo-recent.lock
+++ b/Cargo-recent.lock
@@ -89,6 +89,7 @@ dependencies = [
  "honggfuzz",
  "serde",
  "serde_json",
+ "standard_test",
 ]
 
 [[package]]
@@ -451,6 +452,15 @@ version = "1.3.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "0fda2ff0d084019ba4d7c6f371c95d8fd75ce3524c3cb8fb653a3023f6323e64"
 
+[[package]]
+name = "standard_test"
+version = "0.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "af4bac6cd647192c3cb6e687af2703eb3a30e9187e555c664520cd848443ae70"
+dependencies = [
+ "arbitrary",
+]
+
 [[package]]
 name = "syn"
 version = "2.0.79"
diff --git a/fuzz/Cargo.toml b/fuzz/Cargo.toml
index 72288071..2b6c372b 100644
--- a/fuzz/Cargo.toml
+++ b/fuzz/Cargo.toml
@@ -18,6 +18,7 @@ arbitrary = { version = "1.4.1" }
 
 serde = { version = "1.0.195", features = [ "derive" ] }
 serde_json = "1.0.68"
+standard_test = "0.1.0"
 
 [lints.rust]
 unexpected_cfgs = { level = "deny", check-cfg = ['cfg(fuzzing)'] }
@@ -141,3 +142,7 @@ path = "fuzz_targets/consensus_encoding/decode_decoder2.rs"
 [[bin]]
 name = "consensus_encoding_decode_byte_vec"
 path = "fuzz_targets/consensus_encoding/decode_byte_vec.rs"
+
+[[bin]]
+name = "units_standard_checks"
+path = "fuzz_targets/units/standard_checks.rs"
diff --git a/fuzz/fuzz_targets/units/standard_checks.rs b/fuzz/fuzz_targets/units/standard_checks.rs
new file mode 100644
index 00000000..933ab633
--- /dev/null
+++ b/fuzz/fuzz_targets/units/standard_checks.rs
@@ -0,0 +1,136 @@
+use bitcoin::{
+    Amount,
+    BlockHeight,
+    BlockHeightInterval,
+    BlockMtp,
+    BlockMtpInterval,
+    BlockTime,
+    FeeRate,
+    Sequence,
+    SignedAmount,
+    Weight,
+    absolute::{
+        Height,
+        MedianTimePast
+    },
+    relative::{
+        NumberOfBlocks,
+        NumberOf512Seconds
+    }
+};
+use standard_test::StandardChecks as _;
+use honggfuzz::fuzz;
+
+/// Implements the traits on the wrapper type $ty. Intended only to be called from inside wrap_for_checks!
+macro_rules! _impl_traits_on_wrapper {
+    ($ty:ident$(, $default:expr)?) => {
+        impl<'a> arbitrary::Arbitrary<'a> for $ty {
+            fn arbitrary(u: &mut arbitrary::Unstructured<'a>) -> arbitrary::Result<Self> {
+                Ok(Self(super::$ty::arbitrary(u)?))
+            }
+        }
+
+        impl core::ops::Deref for $ty {
+            type Target = super::$ty;
+
+            fn deref(&self) -> &Self::Target { &self.0 }
+        }
+
+        $(
+            impl Default for $ty {
+                fn default() -> $ty { Self($default) }
+            }
+        )?
+
+        standard_checks!($ty);
+    };
+}
+
+/// Create a wrapper type for a foreign type so that we can use standard_checks! on it from here.
+macro_rules! wrap_for_checks {
+    ($ty:ident) => {
+        #[derive(Default)]
+        pub(crate) struct $ty (super::$ty);
+
+        _impl_traits_on_wrapper!($ty);
+    };
+    ($ty:ident, $default:expr) => {
+        pub(crate) struct $ty (super::$ty);
+
+        _impl_traits_on_wrapper!($ty, $default);
+    };
+}
+
+
+mod fuzz {
+    use standard_test::standard_checks;
+
+    wrap_for_checks!(Amount);
+    wrap_for_checks!(BlockHeightInterval);
+    wrap_for_checks!(BlockMtpInterval);
+    wrap_for_checks!(NumberOf512Seconds);
+    wrap_for_checks!(NumberOfBlocks);
+    wrap_for_checks!(Sequence);
+    wrap_for_checks!(SignedAmount);
+
+    // Structs that need defaults
+    wrap_for_checks!(BlockHeight, super::BlockHeight::MIN);
+    wrap_for_checks!(BlockMtp, super::BlockMtp::from_u32(1_742_979_600)); // 26 Mar 2025 9:00 UTC
+    wrap_for_checks!(BlockTime, super::BlockTime::from(1_742_979_600)); // 26 Mar 2025 9:00 UTC
+    wrap_for_checks!(FeeRate, super::FeeRate::BROADCAST_MIN);
+    wrap_for_checks!(Height, super::Height::MIN);
+    wrap_for_checks!(MedianTimePast, super::MedianTimePast::MIN);
+    wrap_for_checks!(Weight, super::Weight::MIN_TRANSACTION);
+}
+
+fn do_test(data: &[u8]) {
+    fuzz::Amount::one_iteration(data);
+    fuzz::BlockHeight::one_iteration(data);
+    fuzz::BlockHeightInterval::one_iteration(data);
+    fuzz::BlockMtp::one_iteration(data);
+    fuzz::BlockMtpInterval::one_iteration(data);
+    fuzz::BlockTime::one_iteration(data);
+    fuzz::FeeRate::one_iteration(data);
+    fuzz::Height::one_iteration(data);
+    fuzz::NumberOf512Seconds::one_iteration(data);
+    fuzz::NumberOfBlocks::one_iteration(data);
+    fuzz::MedianTimePast::one_iteration(data);
+    fuzz::Sequence::one_iteration(data);
+    fuzz::SignedAmount::one_iteration(data);
+    fuzz::Weight::one_iteration(data);
+}
+
+fn main() {
+    loop {
+        fuzz!(|data| {
+            do_test(data);
+        });
+    }
+}
+
+#[cfg(all(test, fuzzing))]
+mod tests {
+    fn extend_vec_from_hex(hex: &str, out: &mut Vec<u8>) {
+        let mut b = 0;
+        for (idx, c) in hex.as_bytes().iter().enumerate() {
+            b <<= 4;
+            match *c {
+                b'A'..=b'F' => b |= c - b'A' + 10,
+                b'a'..=b'f' => b |= c - b'a' + 10,
+                b'0'..=b'9' => b |= c - b'0',
+                _ => panic!("Bad hex"),
+            }
+            if (idx & 1) == 1 {
+                out.push(b);
+                b = 0;
+            }
+        }
+    }
+
+    #[test]
+    fn duplicate_crash() {
+        let mut a = Vec::new();
+        extend_vec_from_hex("00000000", &mut a);
+        super::do_test(&a);
+    }
+}
diff --git a/fuzz/generate-files.sh b/fuzz/generate-files.sh
index 2471c5ac..c0c9cb5f 100755
--- a/fuzz/generate-files.sh
+++ b/fuzz/generate-files.sh
@@ -29,6 +29,7 @@ arbitrary = { version = "1.4.1" }
 
 serde = { version = "1.0.195", features = [ "derive" ] }
 serde_json = "1.0.68"
+standard_test = "0.1.0"
 
 [lints.rust]
 unexpected_cfgs = { level = "deny", check-cfg = ['cfg(fuzzing)'] }