feat(nargo): Mock oracle resolver

Adds a `--mock-oracle-resolver` option to nargo, that responds to all oracle requests with a single zero-value field. Useful for allowing noop oracle calls, such as debug-log, when running circuits in aztec-packages, without breaking tests run via `nargo test`.

Co-authored-by: Nicolás Venturo <nicolas.venturo@gmail.com>

noir-projects/Dockerfile

@@ -14,11 +14,11 @@ WORKDIR /usr/src/noir-projects
 COPY . .
 # Build
 WORKDIR /usr/src/noir-projects/noir-contracts
-RUN ./bootstrap.sh && nargo test --silence-warnings
+RUN ./bootstrap.sh && nargo test --silence-warnings --mock-oracle-resolver
 WORKDIR /usr/src/noir-projects/noir-protocol-circuits
-RUN ./bootstrap.sh && nargo test --silence-warnings
+RUN ./bootstrap.sh && nargo test --silence-warnings --mock-oracle-resolver
 WORKDIR /usr/src/noir-projects/aztec-nr
-RUN nargo test --silence-warnings
+RUN nargo test --silence-warnings --mock-oracle-resolver
 
 FROM scratch
 COPY --from=builder /usr/src/noir-projects /usr/src/noir-projects

noir-projects/Earthfile

@@ -26,6 +26,6 @@ build:
 
 test:
   FROM +build
-  RUN cd noir-protocol-circuits && nargo test --silence-warnings
-  RUN cd aztec-nr && nargo test --silence-warnings
-  RUN cd noir-contracts && nargo test --silence-warnings
+  RUN cd noir-protocol-circuits && nargo test --silence-warnings --mock-oracle-resolver
+  RUN cd aztec-nr && nargo test --silence-warnings --mock-oracle-resolver
+  RUN cd noir-contracts && nargo test --silence-warnings --mock-oracle-resolver

noir/noir-repo/tooling/acvm_cli/src/cli/execute_cmd.rs

@@ -7,7 +7,7 @@ use clap::Args;
 
 use crate::cli::fs::inputs::{read_bytecode_from_file, read_inputs_from_file};
 use crate::errors::CliError;
-use nargo::ops::{execute_program, DefaultForeignCallExecutor};
+use nargo::ops::{execute_program, DefaultForeignCallExecutor, ResolverOpts};
 
 use super::fs::witness::{create_output_witness_string, save_witness_to_dir};
 
@@ -38,7 +38,8 @@ pub(crate) struct ExecuteCommand {
 fn run_command(args: ExecuteCommand) -> Result<String, CliError> {
     let bytecode = read_bytecode_from_file(&args.working_directory, &args.bytecode)?;
     let circuit_inputs = read_inputs_from_file(&args.working_directory, &args.input_witness)?;
-    let output_witness = execute_program_from_witness(circuit_inputs, &bytecode, None)?;
+    let output_witness =
+        execute_program_from_witness(circuit_inputs, &bytecode, &ResolverOpts::none())?;
     assert_eq!(output_witness.length(), 1, "ACVM CLI only supports a witness stack of size 1");
     let output_witness_string = create_output_witness_string(
         &output_witness.peek().expect("Should have a witness stack item").witness,
@@ -65,7 +66,7 @@ pub(crate) fn run(args: ExecuteCommand) -> Result<String, CliError> {
 pub(crate) fn execute_program_from_witness(
     inputs_map: WitnessMap,
     bytecode: &[u8],
-    foreign_call_resolver_url: Option<&str>,
+    resolver_opts: &ResolverOpts,
 ) -> Result<WitnessStack, CliError> {
     let blackbox_solver = Bn254BlackBoxSolver::new();
     let program: Program = Program::deserialize_program(bytecode)
@@ -74,7 +75,7 @@ pub(crate) fn execute_program_from_witness(
         &program,
         inputs_map,
         &blackbox_solver,
-        &mut DefaultForeignCallExecutor::new(true, foreign_call_resolver_url),
+        &mut DefaultForeignCallExecutor::new(true, resolver_opts),
     )
     .map_err(CliError::CircuitExecutionError)
 }

noir/noir-repo/tooling/debugger/src/foreign_calls.rs

@@ -5,7 +5,7 @@ use acvm::{
 };
 use nargo::{
     artifacts::debug::{DebugArtifact, DebugVars, StackFrame},
-    ops::{DefaultForeignCallExecutor, ForeignCallExecutor},
+    ops::{DefaultForeignCallExecutor, ForeignCallExecutor, ResolverOpts},
 };
 use noirc_errors::debug_info::{DebugFnId, DebugVarId};
 use noirc_printable_type::ForeignCallError;
@@ -51,7 +51,7 @@ pub struct DefaultDebugForeignCallExecutor {
 impl DefaultDebugForeignCallExecutor {
     pub fn new(show_output: bool) -> Self {
         Self {
-            executor: DefaultForeignCallExecutor::new(show_output, None),
+            executor: DefaultForeignCallExecutor::new(show_output, &ResolverOpts::none()),
             debug_vars: DebugVars::default(),
         }
     }

noir/noir-repo/tooling/lsp/src/requests/test_run.rs

@@ -3,7 +3,7 @@ use std::future::{self, Future};
 use async_lsp::{ErrorCode, ResponseError};
 use nargo::{
     insert_all_files_for_workspace_into_file_manager,
-    ops::{run_test, TestStatus},
+    ops::{run_test, ResolverOpts, TestStatus},
     prepare_package,
 };
 use nargo_toml::{find_package_manifest, resolve_workspace_from_toml, PackageSelection};
@@ -86,7 +86,7 @@ fn on_test_run_request_inner(
                 &mut context,
                 &test_function,
                 false,
-                None,
+                &ResolverOpts::none(),
                 &CompileOptions::default(),
             );
             let result = match test_result {

noir/noir-repo/tooling/nargo/src/ops/foreign_calls.rs

@@ -94,6 +94,51 @@ impl MockedCall {
     }
 }
 
+trait ExternalResolver: std::fmt::Debug {
+    fn execute(&self, call: &ForeignCallWaitInfo) -> ForeignCallResult;
+}
+
+#[derive(Debug)]
+struct JsonRpcExternalResolver {
+    client: Client,
+}
+
+impl JsonRpcExternalResolver {
+    fn new(resolver_url: &str) -> Self {
+        let mut transport_builder =
+            Builder::new().url(resolver_url).expect("Invalid oracle resolver URL");
+
+        if let Some(Ok(timeout)) =
+            std::env::var("NARGO_FOREIGN_CALL_TIMEOUT").ok().map(|timeout| timeout.parse())
+        {
+            let timeout_duration = std::time::Duration::from_millis(timeout);
+            transport_builder = transport_builder.timeout(timeout_duration);
+        };
+
+        let client = Client::with_transport(transport_builder.build());
+
+        JsonRpcExternalResolver { client }
+    }
+}
+
+impl ExternalResolver for JsonRpcExternalResolver {
+    fn execute(&self, call: &ForeignCallWaitInfo) -> ForeignCallResult {
+        let encoded_params: Vec<_> = call.inputs.iter().map(build_json_rpc_arg).collect();
+        let request = self.client.build_request(call.function.as_str(), &encoded_params);
+        let response = self.client.send_request(request).expect("Failed to send request");
+        response.result().expect("Failed to parse response")
+    }
+}
+
+#[derive(Debug)]
+struct MockExternalResolver;
+
+impl ExternalResolver for MockExternalResolver {
+    fn execute(&self, _call: &ForeignCallWaitInfo) -> ForeignCallResult {
+        FieldElement::from(0_usize).into()
+    }
+}
+
 #[derive(Debug, Default)]
 pub struct DefaultForeignCallExecutor {
     /// Mocks have unique ids used to identify them in Noir, allowing to update or remove them.
@@ -102,27 +147,54 @@ pub struct DefaultForeignCallExecutor {
     mocked_responses: Vec<MockedCall>,
     /// Whether to print [`ForeignCall::Print`] output.
     show_output: bool,
-    /// JSON RPC client to resolve foreign calls
-    external_resolver: Option<Client>,
+    /// External resolver for foreign calls
+    external_resolver: Option<Box<dyn ExternalResolver>>,
+}
+
+#[derive(Debug)]
+pub struct ResolverOpts {
+    pub resolver_url: Option<String>,
+    pub mock_resolver: bool,
+}
+
+impl ResolverOpts {
+    pub fn new(resolver_url: Option<&str>, mock_resolver: bool) -> Self {
+        Self {
+            resolver_url: resolver_url.map(|resolver_url| resolver_url.to_string()),
+            mock_resolver,
+        }
+    }
+
+    pub fn none() -> Self {
+        Self { resolver_url: None, mock_resolver: false }
+    }
+
+    pub fn rpc(resolver_url: &str) -> Self {
+        Self { resolver_url: Some(resolver_url.to_string()), mock_resolver: false }
+    }
+
+    pub fn mock() -> Self {
+        Self { resolver_url: None, mock_resolver: true }
+    }
 }
 
 impl DefaultForeignCallExecutor {
-    pub fn new(show_output: bool, resolver_url: Option<&str>) -> Self {
-        let oracle_resolver = resolver_url.map(|resolver_url| {
-            let mut transport_builder =
-                Builder::new().url(resolver_url).expect("Invalid oracle resolver URL");
-
-            if let Some(Ok(timeout)) =
-                std::env::var("NARGO_FOREIGN_CALL_TIMEOUT").ok().map(|timeout| timeout.parse())
-            {
-                let timeout_duration = std::time::Duration::from_millis(timeout);
-                transport_builder = transport_builder.timeout(timeout_duration);
+    pub fn new(show_output: bool, resolver: &ResolverOpts) -> Self {
+        let ResolverOpts { resolver_url, mock_resolver } = resolver;
+        let external_resolver: Option<Box<dyn ExternalResolver>> =
+            match (resolver_url, mock_resolver) {
+                (Some(_), true) => {
+                    panic!("Cannot have both an external resolver and a mock resolver")
+                }
+                (Some(resolver_url), _) => {
+                    Some(Box::new(JsonRpcExternalResolver::new(resolver_url.as_str())))
+                }
+                (None, true) => Some(Box::new(MockExternalResolver {})),
+                _ => None,
             };
-            Client::with_transport(transport_builder.build())
-        });
         DefaultForeignCallExecutor {
             show_output,
-            external_resolver: oracle_resolver,
+            external_resolver,
             ..DefaultForeignCallExecutor::default()
         }
     }
@@ -269,19 +341,7 @@ impl ForeignCallExecutor for DefaultForeignCallExecutor {
 
                         Ok(result.into())
                     }
-                    (None, Some(external_resolver)) => {
-                        let encoded_params: Vec<_> =
-                            foreign_call.inputs.iter().map(build_json_rpc_arg).collect();
-
-                        let req =
-                            external_resolver.build_request(foreign_call_name, &encoded_params);
-
-                        let response = external_resolver.send_request(req)?;
-
-                        let parsed_response: ForeignCallResult = response.result()?;
-
-                        Ok(parsed_response)
-                    }
+                    (None, Some(external_resolver)) => Ok(external_resolver.execute(foreign_call)),
                     (None, None) => panic!(
                         "No mock for foreign call {}({:?})",
                         foreign_call_name, &foreign_call.inputs
@@ -302,7 +362,9 @@ mod tests {
     use jsonrpc_derive::rpc;
     use jsonrpc_http_server::{Server, ServerBuilder};
 
-    use crate::ops::{DefaultForeignCallExecutor, ForeignCallExecutor};
+    use crate::ops::{
+        foreign_calls::ResolverOpts, DefaultForeignCallExecutor, ForeignCallExecutor,
+    };
 
     #[allow(unreachable_pub)]
     #[rpc]
@@ -349,7 +411,7 @@ mod tests {
     fn test_oracle_resolver_echo() {
         let (server, url) = build_oracle_server();
 
-        let mut executor = DefaultForeignCallExecutor::new(false, Some(&url));
+        let mut executor = DefaultForeignCallExecutor::new(false, &ResolverOpts::rpc(&url));
 
         let foreign_call = ForeignCallWaitInfo {
             function: "echo".to_string(),
@@ -366,7 +428,7 @@ mod tests {
     fn test_oracle_resolver_sum() {
         let (server, url) = build_oracle_server();
 
-        let mut executor = DefaultForeignCallExecutor::new(false, Some(&url));
+        let mut executor = DefaultForeignCallExecutor::new(false, &ResolverOpts::rpc(&url));
 
         let foreign_call = ForeignCallWaitInfo {
             function: "sum".to_string(),
@@ -378,4 +440,17 @@ mod tests {
 
         server.close();
     }
+
+    #[test]
+    fn test_mock_resolver() {
+        let mut executor = DefaultForeignCallExecutor::new(false, &ResolverOpts::mock());
+
+        let foreign_call = ForeignCallWaitInfo {
+            function: "sum".to_string(),
+            inputs: vec![ForeignCallParam::Array(vec![1_usize.into(), 2_usize.into()])],
+        };
+
+        let result = executor.execute(&foreign_call);
+        assert_eq!(result.unwrap(), FieldElement::from(0_usize).into());
+    }
 }

noir/noir-repo/tooling/nargo/src/ops/mod.rs

@@ -3,7 +3,9 @@ pub use self::compile::{
     compile_workspace, report_errors,
 };
 pub use self::execute::execute_program;
-pub use self::foreign_calls::{DefaultForeignCallExecutor, ForeignCall, ForeignCallExecutor};
+pub use self::foreign_calls::{
+    DefaultForeignCallExecutor, ForeignCall, ForeignCallExecutor, ResolverOpts,
+};
 pub use self::optimize::{optimize_contract, optimize_program};
 pub use self::transform::{transform_contract, transform_program};
 

noir/noir-repo/tooling/nargo/src/ops/test.rs

@@ -9,7 +9,7 @@ use noirc_frontend::hir::{def_map::TestFunction, Context};
 
 use crate::{errors::try_to_diagnose_runtime_error, NargoError};
 
-use super::{execute_program, DefaultForeignCallExecutor};
+use super::{execute_program, DefaultForeignCallExecutor, ResolverOpts};
 
 pub enum TestStatus {
     Pass,
@@ -28,7 +28,7 @@ pub fn run_test<B: BlackBoxFunctionSolver>(
     context: &mut Context,
     test_function: &TestFunction,
     show_output: bool,
-    foreign_call_resolver_url: Option<&str>,
+    resolver_opts: &ResolverOpts,
     config: &CompileOptions,
 ) -> TestStatus {
     let compiled_program = compile_no_check(context, config, test_function.get_id(), None, false);
@@ -40,7 +40,7 @@ pub fn run_test<B: BlackBoxFunctionSolver>(
                 &compiled_program.program,
                 WitnessMap::new(),
                 blackbox_solver,
-                &mut DefaultForeignCallExecutor::new(show_output, foreign_call_resolver_url),
+                &mut DefaultForeignCallExecutor::new(show_output, resolver_opts),
             );
             test_status_program_compile_pass(
                 test_function,

noir/noir-repo/tooling/nargo_cli/src/cli/execute_cmd.rs

@@ -5,7 +5,7 @@ use clap::Args;
 use nargo::artifacts::debug::DebugArtifact;
 use nargo::constants::PROVER_INPUT_FILE;
 use nargo::errors::try_to_diagnose_runtime_error;
-use nargo::ops::{compile_program, report_errors, DefaultForeignCallExecutor};
+use nargo::ops::{compile_program, report_errors, DefaultForeignCallExecutor, ResolverOpts};
 use nargo::package::Package;
 use nargo::{insert_all_files_for_workspace_into_file_manager, parse_all};
 use nargo_toml::{get_package_manifest, resolve_workspace_from_toml, PackageSelection};
@@ -46,6 +46,10 @@ pub(crate) struct ExecuteCommand {
     /// JSON RPC url to solve oracle calls
     #[clap(long)]
     oracle_resolver: Option<String>,
+
+    /// Use a mock oracle resolver that returns zero to every request
+    #[clap(long)]
+    mock_oracle_resolver: bool,
 }
 
 pub(crate) fn run(
@@ -91,11 +95,14 @@ pub(crate) fn run(
 
         let compiled_program = nargo::ops::transform_program(compiled_program, expression_width);
 
+        let resolver_opts =
+            ResolverOpts::new(args.oracle_resolver.as_deref(), args.mock_oracle_resolver);
+
         let (return_value, witness_stack) = execute_program_and_decode(
             compiled_program,
             package,
             &args.prover_name,
-            args.oracle_resolver.as_deref(),
+            &resolver_opts,
         )?;
 
         println!("[{}] Circuit witness successfully solved", package.name);
@@ -115,12 +122,12 @@ fn execute_program_and_decode(
     program: CompiledProgram,
     package: &Package,
     prover_name: &str,
-    foreign_call_resolver_url: Option<&str>,
+    resolver_opts: &ResolverOpts,
 ) -> Result<(Option<InputValue>, WitnessStack), CliError> {
     // Parse the initial witness values from Prover.toml
     let (inputs_map, _) =
         read_inputs_from_file(&package.root_dir, prover_name, Format::Toml, &program.abi)?;
-    let witness_stack = execute_program(&program, &inputs_map, foreign_call_resolver_url)?;
+    let witness_stack = execute_program(&program, &inputs_map, resolver_opts)?;
     let public_abi = program.abi.public_abi();
     // Get the entry point witness for the ABI
     let main_witness =
@@ -133,7 +140,7 @@ fn execute_program_and_decode(
 pub(crate) fn execute_program(
     compiled_program: &CompiledProgram,
     inputs_map: &InputMap,
-    foreign_call_resolver_url: Option<&str>,
+    resolver_opts: &ResolverOpts,
 ) -> Result<WitnessStack, CliError> {
     let blackbox_solver = Bn254BlackBoxSolver::new();
 
@@ -143,7 +150,7 @@ pub(crate) fn execute_program(
         &compiled_program.program,
         initial_witness,
         &blackbox_solver,
-        &mut DefaultForeignCallExecutor::new(true, foreign_call_resolver_url),
+        &mut DefaultForeignCallExecutor::new(true, resolver_opts),
     );
     match solved_witness_stack_err {
         Ok(solved_witness_stack) => Ok(solved_witness_stack),