fix(runtime): Fix empty method_names bug (#2188)

Fixes: #2183

# Test plan:
- Extracted the code into utils crate and added unit tests.

runtime/near-runtime-fees/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "near-runtime-fees"
-version = "0.4.4"
+version = "0.4.5"
 authors = ["Near Inc <[email protected]>"]
 edition = "2018"
 license = "Apache-2.0"

runtime/near-vm-errors/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "near-vm-errors"
-version = "0.4.4"
+version = "0.4.5"
 authors = ["Near Inc <[email protected]>"]
 edition = "2018"
 license = "Apache-2.0"

runtime/near-vm-logic/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "near-vm-logic"
-version = "0.4.4"
+version = "0.4.5"
 authors = ["Near Inc <[email protected]>"]
 edition = "2018"
 license = "Apache-2.0"
@@ -16,8 +16,8 @@ This crate implements the specification of the interface that Near blockchain ex
 byteorder = "1.2"
 bs58 = "0.3"
 serde = { version = "1.0", features = ["derive"] }
-near-runtime-fees = { path = "../near-runtime-fees", version = "0.4.4" }
-near-vm-errors = { path = "../near-vm-errors", version = "0.4.4" }
+near-runtime-fees = { path = "../near-runtime-fees", version = "0.4.5" }
+near-vm-errors = { path = "../near-vm-errors", version = "0.4.5" }
 
 [dev-dependencies]
 serde_json = {version= "1.0", features= ["preserve_order"]}

runtime/near-vm-logic/src/lib.rs

@@ -6,8 +6,9 @@ mod logic;
 #[cfg(not(target_arch = "wasm32"))]
 pub mod mocks;
 pub mod serde_with;
-
 pub mod types;
+mod utils;
+
 pub use config::{ExtCosts, ExtCostsConfig, VMConfig, VMLimitConfig};
 pub use context::VMContext;
 pub use dependencies::{External, MemoryLike, ValuePtr};

runtime/near-vm-logic/src/logic.rs

@@ -7,6 +7,7 @@ use crate::types::{
     AccountId, Balance, Gas, IteratorIndex, PromiseIndex, PromiseResult, ReceiptIndex, ReturnData,
     StorageUsage,
 };
+use crate::utils::split_method_names;
 use crate::{ExtCosts, HostError, VMLogicError, ValuePtr};
 use byteorder::ByteOrder;
 use near_runtime_fees::RuntimeFeesConfig;
@@ -1436,20 +1437,9 @@ impl<'a> VMLogic<'a> {
         let allowance = self.memory_get_u128(allowance_ptr)?;
         let allowance = if allowance > 0 { Some(allowance) } else { None };
         let receiver_id = self.read_and_parse_account_id(receiver_id_ptr, receiver_id_len)?;
-        let method_names =
+        let raw_method_names =
             self.get_vec_from_memory_or_register(method_names_ptr, method_names_len)?;
-        // Use `,` separator to split `method_names` into a vector of method names.
-        let method_names =
-            method_names
-                .split(|c| *c == b',')
-                .map(|v| {
-                    if v.is_empty() {
-                        Err(HostError::EmptyMethodName.into())
-                    } else {
-                        Ok(v.to_vec())
-                    }
-                })
-                .collect::<Result<Vec<_>>>()?;
+        let method_names = split_method_names(&raw_method_names)?;
 
         let (receipt_idx, sir) = self.promise_idx_to_receipt_idx_with_sir(promise_idx)?;
 

runtime/near-vm-logic/src/utils.rs

@@ -0,0 +1,80 @@
+use near_vm_errors::{HostError, VMLogicError};
+
+type Result<T> = ::std::result::Result<T, VMLogicError>;
+
+/// Uses `,` separator to split `method_names` into a vector of method names.
+/// Returns an empty vec if the empty slice is given.
+/// Throws `HostError::EmptyMethodName` in case there is an empty method name inside.
+pub(crate) fn split_method_names(method_names: &[u8]) -> Result<Vec<Vec<u8>>> {
+    if method_names.is_empty() {
+        Ok(vec![])
+    } else {
+        method_names
+            .split(|c| *c == b',')
+            .map(
+                |v| {
+                    if v.is_empty() {
+                        Err(HostError::EmptyMethodName.into())
+                    } else {
+                        Ok(v.to_vec())
+                    }
+                },
+            )
+            .collect::<Result<Vec<_>>>()
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_split_method_names_empty() {
+        assert_eq!(split_method_names(b""), Ok(vec![]));
+    }
+
+    #[test]
+    fn test_split_method_one_name() {
+        assert_eq!(split_method_names(b"hello"), Ok(vec![b"hello".to_vec()]));
+    }
+
+    #[test]
+    fn test_split_method_two_method_names() {
+        assert_eq!(
+            split_method_names(b"hello,world"),
+            Ok(vec![b"hello".to_vec(), b"world".to_vec()])
+        );
+    }
+
+    #[test]
+    fn test_split_empty_method_name_inside() {
+        assert_eq!(
+            split_method_names(b"hello,,world"),
+            Err(VMLogicError::HostError(HostError::EmptyMethodName))
+        );
+    }
+
+    #[test]
+    fn test_split_empty_method_name_front() {
+        assert_eq!(
+            split_method_names(b",world"),
+            Err(VMLogicError::HostError(HostError::EmptyMethodName))
+        );
+    }
+
+    #[test]
+    fn test_split_empty_method_name_back() {
+        assert_eq!(
+            split_method_names(b"world,"),
+            Err(VMLogicError::HostError(HostError::EmptyMethodName))
+        );
+    }
+
+    #[test]
+    fn test_split_empty_method_name_comma_only() {
+        assert_eq!(
+            split_method_names(b","),
+            Err(VMLogicError::HostError(HostError::EmptyMethodName))
+        );
+    }
+}

runtime/near-vm-runner-standalone/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "near-vm-runner-standalone"
-version = "0.4.4"
+version = "0.4.5"
 authors = ["Near Inc <[email protected]>"]
 edition = "2018"
 license = "Apache-2.0"
@@ -21,6 +21,6 @@ to make sure it has expected behavior once deployed to the blockchain.
 [dependencies]
 serde_json = "1.0"
 clap = "2.33.0"
-near-vm-logic = { path = "../near-vm-logic", version = "0.4.4"}
-near-vm-runner = { path = "../near-vm-runner", version = "0.4.4" }
-near-runtime-fees = { path = "../near-runtime-fees", version = "0.4.4" }
+near-vm-logic = { path = "../near-vm-logic", version = "0.4.5"}
+near-vm-runner = { path = "../near-vm-runner", version = "0.4.5" }
+near-runtime-fees = { path = "../near-runtime-fees", version = "0.4.5" }

runtime/near-vm-runner/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "near-vm-runner"
-version = "0.4.4"
+version = "0.4.5"
 authors = ["Near Inc <[email protected]>"]
 edition = "2018"
 license = "Apache-2.0"
@@ -16,9 +16,9 @@ This crate implements the specification of the interface that Near blockchain ex
 cached = "0.11.0"
 wasmer-runtime = { version = "0.13.1", features = ["default-backend-singlepass"], default-features = false }
 wasmer-runtime-core = { version = "0.13.1" }
-near-runtime-fees = { path="../near-runtime-fees", version = "0.4.4" }
-near-vm-logic = { path="../near-vm-logic", version = "0.4.4", default-features = false, features = []}
-near-vm-errors = { path = "../near-vm-errors", version = "0.4.4" }
+near-runtime-fees = { path="../near-runtime-fees", version = "0.4.5" }
+near-vm-logic = { path="../near-vm-logic", version = "0.4.5", default-features = false, features = []}
+near-vm-errors = { path = "../near-vm-errors", version = "0.4.5" }
 pwasm-utils = "0.12.0"
 parity-wasm = "0.41.0"
 wasmparser = "0.44"