feat: implement Blob commitment calculation

types/Cargo.toml

@@ -6,6 +6,7 @@ license = "Apache-2.0"
 
 [dependencies]
 base64 = "0.21.2"
+bytes = "1.4.0"
 celestia-proto = { workspace = true }
 nmt-rs = { git = "https://github.com/eigerco/nmt-rs.git", rev = "a371723" }
 serde = { version = "1.0.164", features = ["derive"] }

types/src/blob.rs

@@ -3,12 +3,14 @@ use tendermint_proto::v0_34::types::Blob as RawBlob;
 use tendermint_proto::Protobuf;
 
 use crate::nmt::Namespace;
-use crate::Error;
+use crate::{Error, Result};
+
+mod commitment;
 
 // NOTE: We don't use the `serde(try_from)` pattern for this type
 // becase JSON representation needs to have `commitment` field but
 // Protobuf definition doesn't.
-#[derive(Debug, Clone, Serialize, Deserialize)]
+#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
 pub struct Blob {
     pub namespace: Namespace,
     #[serde(with = "tendermint_proto::serializers::bytes::base64string")]
@@ -25,10 +27,10 @@ impl TryFrom<RawBlob> for Blob {
 
     fn try_from(value: RawBlob) -> Result<Self, Self::Error> {
         Ok(Blob {
+            commitment: commitment::create_commitment(&value)?,
             namespace: Namespace::new(value.namespace_version as u8, &value.namespace_id)?,
             data: value.data,
             share_version: value.share_version as u8,
-            commitment: Vec::new(),
         })
     }
 }
@@ -43,3 +45,29 @@ impl From<Blob> for RawBlob {
         }
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    fn sample_blob() -> Blob {
+        serde_json::from_str(
+            r#"{
+              "namespace": "AAAAAAAAAAAAAAAAAAAAAAAAAAAADCBNOWAP3dM=",
+              "data": "8fIMqAB+kQo7+LLmHaDya8oH73hxem6lQWX1",
+              "share_version": 0,
+              "commitment": "D6YGsPWdxR8ju2OcOspnkgPG2abD30pSHxsFdiPqnVk="
+            }"#,
+        )
+        .unwrap()
+    }
+
+    #[test]
+    fn create_from_raw() {
+        let expected = sample_blob();
+        let raw = RawBlob::try_from(expected.clone()).unwrap();
+        let created = Blob::try_from(raw).unwrap();
+
+        assert_eq!(created, expected);
+    }
+}