fix(rust): validate config on client construction (#748)

Description of changes:
In the Rust codegen, constraint validation is performed on operation calls instead of within structure builders' build() function. (The reasoning for this choice is documented in the description of #582.) But the validation wasn't applied to the constructors of localService clients, so attempting to construct a client with an invalid config could panic during conversion (in particular, when a @required field was missing).

This PR implements the missing validation in client constructors, and tests that both valid and invalid configs have the expected behavior when passed to the client constructor.

Author: alex-chew

TestModels/Constraints/Model/Constraints.smithy

@@ -15,7 +15,10 @@ service SimpleConstraints {
   errors: [ SimpleConstraintsException ],
 }
 
-structure SimpleConstraintsConfig {}
+structure SimpleConstraintsConfig {
+  @required
+  RequiredString: String,
+}
 
 // This is just a sanity check on the smokeTests support.
 // We need to actually convert all the tests in test/WrappedSimpleConstraintsImplTest.dfy
@@ -24,6 +27,9 @@ structure SimpleConstraintsConfig {}
 @smithy.test#smokeTests([
   {
     id: "GetConstraintsSuccess"
+    vendorParams: {
+      RequiredString: "foobar",
+    }
     params: {
       OneToTen: 5,
       GreaterThanOne: 2,
@@ -40,6 +46,9 @@ structure SimpleConstraintsConfig {}
   },
   {
     id: "GetConstraintsFailure"
+    vendorParams: {
+      RequiredString: "foobar",
+    }
     params: {
       // These two always have to be present because of https://github.com/smithy-lang/smithy-dafny/issues/278,
       // because otherwise they are interpreted as 0.
@@ -51,6 +60,14 @@ structure SimpleConstraintsConfig {}
     expect: {
         failure: {}
     }
+  },
+  {
+    id: "GetConstraintsInvalidConfig"
+    params: {}
+    expect: {
+      failure: {}
+    },
+    tags: ["INVALID_CONFIG"]
   }
 ])
 operation GetConstraints {

TestModels/Constraints/runtimes/rust/tests/simple_constraints_test.rs

@@ -5,10 +5,26 @@ mod simple_constraints_test {
     use simple_constraints::*;
 
     fn client() -> Client {
-        let config = SimpleConstraintsConfig::builder().build().expect("config");
+        let config = SimpleConstraintsConfig::builder()
+            .required_string("test string")
+            .build()
+            .expect("config");
         client::Client::from_conf(config).expect("client")
     }
 
+    #[test]
+    fn test_config_missing_field() {
+        let config = SimpleConstraintsConfig::builder()
+            .build()
+            .expect("config");
+        let error = client::Client::from_conf(config).err().expect("err");
+        assert!(matches!(
+            error,
+            simple_constraints::types::error::Error::ValidationError(..)
+        ));
+        assert!(error.to_string().contains("required_string"));
+    }
+
     #[tokio::test]
     async fn test_empty_input() {
         let result = client().get_constraints().send().await;

TestModels/Constraints/src/Index.dfy

@@ -6,7 +6,7 @@ module {:extern "simple.constraints.internaldafny" } SimpleConstraints refines A
   import Operations = SimpleConstraintsImpl
 
   function method DefaultSimpleConstraintsConfig(): SimpleConstraintsConfig {
-    SimpleConstraintsConfig
+    SimpleConstraintsConfig(RequiredString := "default")
   }
 
   method SimpleConstraints(config: SimpleConstraintsConfig)

TestModels/Constraints/src/WrappedSimpleConstraintsImpl.dfy

@@ -5,6 +5,6 @@ include "../Model/SimpleConstraintsTypesWrapped.dfy"
 module {:extern "simple.constraints.internaldafny.wrapped"} WrappedSimpleConstraintsService refines WrappedAbstractSimpleConstraintsService {
     import WrappedService = SimpleConstraints
     function method WrappedDefaultSimpleConstraintsConfig(): SimpleConstraintsConfig {
-        SimpleConstraintsConfig
+        SimpleConstraintsConfig(RequiredString := "default")
     }
 }

TestModels/dafny-dependencies/StandardLibrary/Makefile

@@ -114,13 +114,13 @@ transpile_implementation:
 # Override SharedMakefile's build_java to not install
 # StandardLibrary as a dependency
 build_java: transpile_java
-	gradle -p runtimes/java build
+	$(GRADLEW) -p runtimes/java build
 
 # Override SharedMakefile's mvn_local_deploy to
 # issue warning
 mvn_local_deploy:
 	@echo "${RED}Warning!!${YELLOW} Installing TestModel's STD to Maven Local replaces ESDK's STD!\n$(RESET)" >&2
-	gradle -p runtimes/java publishToMavenLocal
+	$(GRADLEW) -p runtimes/java publishToMavenLocal
 
 dafny_benerate: DAFNY_RUST_OUTPUT=\
 	runtimes/rust/implementation_from_dafny

codegen/smithy-dafny-codegen/src/main/java/software/amazon/polymorph/smithyjava/generator/library/ModelTestCodegen.java

@@ -18,6 +18,7 @@
 import software.amazon.polymorph.smithyjava.generator.Generator;
 import software.amazon.polymorph.smithyjava.modeled.ModeledShapeValue;
 import software.amazon.polymorph.traits.LocalServiceTrait;
+import software.amazon.smithy.model.node.ObjectNode;
 import software.amazon.smithy.model.shapes.OperationShape;
 import software.amazon.smithy.model.shapes.Shape;
 import software.amazon.smithy.model.shapes.ShapeId;
@@ -29,9 +30,32 @@
  * e.g. generating JUnit tests from traits like @smithy.test#smokeTests.
  * This is distinct from the Dafny testing code
  * and the testing wrapper to support it generated by TestJavaLibrary.
+ *
+ * <h1>Smoke test generation</h1>
+ *
+ * If the {@code vendorParams} property is present,
+ * the generated test constructs the client config with its values.
+ *
+ * <h2>Assertions</h2>
+ *
+ * If {@code "INVALID_CONFIG"} is present in the test case's {@code tags},
+ * the generated test asserts that an exception is thrown
+ * during either client config construction or client construction,
+ * and the test neither constructs the operation input nor performs the operation call.
+ * <p>
+ * Otherwise, if the {@code expect.success} property is present,
+ * the generated test asserts that no exception is thrown
+ * during the operation call and all setup steps
+ * (construction of client config, client, and operation input).
+ * <p>
+ * Otherwise, if the {@code expect.failure} property is present,
+ * the generated test asserts that an exception is thrown
+ * during either operation input construction or the operation call.
  */
 public class ModelTestCodegen extends Generator {
 
+  static final String INVALID_CONFIG_TAG = "INVALID_CONFIG";
+
   final JavaLibrary subject;
 
   public ModelTestCodegen(JavaLibrary subject) {
@@ -86,29 +110,42 @@ private MethodSpec smokeTest(
       configShapeId
     );
 
-    // SimpleConstraintsConfig config = SimpleConstraintsConfig.builder().build();
+    // SimpleConstraintsConfig config = SimpleConstraintsConfig.builder()
+    //     ...
+    //     (multiple .foo(...) calls to populate builder)
+    //     ...
+    //     .build();
     // SimpleConstraints client = SimpleConstraints.builder()
-    //         .SimpleConstraintsConfig(config)
-    //         .build();
-    method.addStatement(
-      "$T config = $T.builder().build()",
-      configType,
-      configType
-    );
-    method.addStatement(
-      "$T client = $T.builder().$N(config).build()",
-      clientType,
-      clientType,
-      configShapeId.getName()
+    //     .SimpleConstraintsConfig(config)
+    //     .build();
+    final ObjectNode configParams = testCase
+      .getVendorParams()
+      .orElseGet(() -> ObjectNode.builder().build());
+    final CodeBlock configValue = ModeledShapeValue.shapeValue(
+      subject,
+      false,
+      subject.model.expectShape(configShapeId),
+      configParams
     );
+    final CodeBlock configAndClientConstruction = CodeBlock
+      .builder()
+      .addStatement("$T config = $L", configType, configValue)
+      .addStatement(
+        "$T client = $T.builder().$N(config).build()",
+        clientType,
+        clientType,
+        configShapeId.getName()
+      )
+      .build();
 
     // GetConstraintsInput input = GetConstraintsInput.builder()
-    // ...
-    // (multiple .foo(...) calls to populate builder)
-    // ...
-    // .build();
+    //     ...
+    //     (multiple .foo(...) calls to populate builder)
+    //     ...
+    //     .build();
+    // client.GetConstraints(input);
     final Shape inputShape = subject.model.expectShape(
-      operationShape.getInput().get()
+      operationShape.getInput().orElseThrow()
     );
     final TypeName inputType = subject.nativeNameResolver.typeForShape(
       inputShape.getId()
@@ -117,17 +154,25 @@ private MethodSpec smokeTest(
       subject,
       false,
       inputShape,
-      testCase.getParams().get()
+      testCase.getParams().orElseThrow()
     );
     final CodeBlock inputAndClientCall = CodeBlock
       .builder()
       .addStatement("$T input = $L", inputType, inputValue)
       .addStatement("client.$L(input)", operationName)
       .build();
 
-    if (testCase.getExpectation().isSuccess()) {
+    if (testCase.hasTag(INVALID_CONFIG_TAG)) {
+      method.addStatement(
+        "$T.assertThrows(Exception.class, () -> {\n$L\n})",
+        TESTNG_ASSERT,
+        configAndClientConstruction.toString()
+      );
+    } else if (testCase.getExpectation().isSuccess()) {
+      method.addCode(configAndClientConstruction);
       method.addCode(inputAndClientCall);
     } else {
+      method.addCode(configAndClientConstruction);
       // We're not specific about what kind of exception for now.
       // If the smokeTests trait gets more specific we can be too.
       // The inputAndClientCall.toString() is necessary because otherwise we get nested

codegen/smithy-dafny-codegen/src/main/java/software/amazon/polymorph/smithyrust/generator/RustLibraryShimGenerator.java

@@ -236,6 +236,18 @@ private RustFile clientModule() {
         )
         .collect(Collectors.joining("\n\n"))
     );
+
+    final StructureShape configShape = ModelUtils.getConfigShape(
+      model,
+      service
+    );
+    variables.put(
+      "inputValidations",
+      new InputValidationGenerator()
+        .generateValidations(model, configShape)
+        .collect(Collectors.joining("\n"))
+    );
+
     final String content = evalTemplateResource(
       getClass(),
       "runtimes/rust/client.rs",
@@ -853,6 +865,9 @@ class InputValidationGenerator
 
     private final Map<String, String> commonVariables;
 
+    /**
+     * Generates validation expressions for operation input structures.
+     */
     InputValidationGenerator(
       final Shape bindingShape,
       final OperationShape operationShape
@@ -862,6 +877,21 @@ class InputValidationGenerator
           serviceVariables(),
           operationVariables(bindingShape, operationShape)
         );
+      this.commonVariables.put(
+          "inputStructureName",
+          commonVariables.get("pascalCaseOperationInputName")
+        );
+    }
+
+    /**
+     * Generates validation expressions for this service's client config structure.
+     */
+    InputValidationGenerator() {
+      this.commonVariables = serviceVariables();
+      this.commonVariables.put(
+          "inputStructureName",
+          commonVariables.get("qualifiedRustConfigName")
+        );
     }
 
     @Override
@@ -871,7 +901,7 @@ protected String validateRequired(final MemberShape memberShape) {
         if input.$fieldName:L.is_none() {
             return ::std::result::Result::Err(::aws_smithy_types::error::operation::BuildError::missing_field(
                 "$fieldName:L",
-                "$fieldName:L was not specified but it is required when building $pascalCaseOperationInputName:L",
+                "$fieldName:L was not specified but it is required when building $inputStructureName:L",
             )).map_err($qualifiedRustServiceErrorType:L::wrap_validation_err);
         }
         """,
@@ -1815,8 +1845,19 @@ protected HashMap<String, String> serviceVariables() {
       service
     );
     final String configName = configShape.getId().getName(service);
+    final String snakeCaseConfigName = toSnakeCase(configName);
+
     variables.put("configName", configName);
-    variables.put("snakeCaseConfigName", toSnakeCase(configName));
+    variables.put("snakeCaseConfigName", snakeCaseConfigName);
+    variables.put(
+      "qualifiedRustConfigName",
+      String.join(
+        "::",
+        getRustTypesModuleName(),
+        snakeCaseConfigName,
+        configName
+      )
+    );
     variables.put("rustErrorModuleName", rustErrorModuleName());
     variables.put(
       "qualifiedRustServiceErrorType",

codegen/smithy-dafny-codegen/src/main/java/software/amazon/polymorph/utils/ConstrainTraitUtils.java

@@ -96,7 +96,10 @@ public Stream<V> generateValidations(
             return validateLength(memberShape, lengthTrait);
           }
           throw new UnsupportedOperationException(
-            "Unsupported constraint trait %s on shape %s".formatted(trait)
+            "Unsupported constraint trait %s on shape %s".formatted(
+                trait,
+                structureShape.getId()
+              )
           );
         });
     }

codegen/smithy-dafny-codegen/src/main/resources/templates/runtimes/rust/client.rs

@@ -10,11 +10,12 @@ impl Client {
     /// Creates a new client from the service [`Config`](crate::Config).
     #[track_caller]
     pub fn from_conf(
-        conf: $rustTypesModuleName:L::$snakeCaseConfigName:L::$configName:L,
-    ) -> Result<Self, $rustTypesModuleName:L::error::Error> {
+        input: $qualifiedRustConfigName:L,
+    ) -> Result<Self, $qualifiedRustServiceErrorType:L> {
+        $inputValidations:L
         let inner =
             crate::$dafnyInternalModuleName:L::_default::$sdkId:L(
-                &$rustConversionsModuleName:L::$snakeCaseConfigName:L::_$snakeCaseConfigName:L::to_dafny(conf),
+                &$rustConversionsModuleName:L::$snakeCaseConfigName:L::_$snakeCaseConfigName:L::to_dafny(input),
             );
         if matches!(
             inner.as_ref(),