sdk: Move `NullSigner` to `signer` module

sdk/src/signature.rs

@@ -12,7 +12,7 @@ use std::{
 use thiserror::Error;
 
 // legacy module paths
-pub use crate::signer::{keypair::*, presigner::*, *};
+pub use crate::signer::{keypair::*, null_signer::*, presigner::*, *};
 
 /// Number of bytes in a signature
 pub const SIGNATURE_BYTES: usize = 64;
@@ -113,39 +113,6 @@ impl FromStr for Signature {
     }
 }
 
-/// NullSigner - A `Signer` implementation that always produces `Signature::default()`.
-/// Used as a placeholder for absentee signers whose 'Pubkey` is required to construct
-/// the transaction
-#[derive(Clone, Debug, Default)]
-pub struct NullSigner {
-    pubkey: Pubkey,
-}
-
-impl NullSigner {
-    pub fn new(pubkey: &Pubkey) -> Self {
-        Self { pubkey: *pubkey }
-    }
-}
-
-impl Signer for NullSigner {
-    fn try_pubkey(&self) -> Result<Pubkey, SignerError> {
-        Ok(self.pubkey)
-    }
-
-    fn try_sign_message(&self, _message: &[u8]) -> Result<Signature, SignerError> {
-        Ok(Signature::default())
-    }
-}
-
-impl<T> PartialEq<T> for NullSigner
-where
-    T: Signer,
-{
-    fn eq(&self, other: &T) -> bool {
-        self.pubkey == other.pubkey()
-    }
-}
-
 #[cfg(test)]
 mod tests {
     use super::*;

sdk/src/signer/mod.rs

@@ -11,6 +11,7 @@ use {
 };
 
 pub mod keypair;
+pub mod null_signer;
 pub mod presigner;
 
 #[derive(Debug, Error, PartialEq)]

sdk/src/signer/null_signer.rs

@@ -0,0 +1,40 @@
+#![cfg(feature = "full")]
+
+use crate::{
+    pubkey::Pubkey,
+    signature::Signature,
+    signer::{Signer, SignerError},
+};
+
+/// NullSigner - A `Signer` implementation that always produces `Signature::default()`.
+/// Used as a placeholder for absentee signers whose 'Pubkey` is required to construct
+/// the transaction
+#[derive(Clone, Debug, Default)]
+pub struct NullSigner {
+    pubkey: Pubkey,
+}
+
+impl NullSigner {
+    pub fn new(pubkey: &Pubkey) -> Self {
+        Self { pubkey: *pubkey }
+    }
+}
+
+impl Signer for NullSigner {
+    fn try_pubkey(&self) -> Result<Pubkey, SignerError> {
+        Ok(self.pubkey)
+    }
+
+    fn try_sign_message(&self, _message: &[u8]) -> Result<Signature, SignerError> {
+        Ok(Signature::default())
+    }
+}
+
+impl<T> PartialEq<T> for NullSigner
+where
+    T: Signer,
+{
+    fn eq(&self, other: &T) -> bool {
+        self.pubkey == other.pubkey()
+    }
+}