[RUST] Fix #22356 / Introduce useSerdePathToError option to improve JSON error messages (#22357)

* Add CLI option

* Add dep to generated Cargo.toml

* Add new `Error::SerdePathToError` error type

* Add `serde_path_to_error` invocation to API layer

* Add sample for serde-path-to-error

* Add arg & docstring to cliOptions as well

* Fix sample

Author: Levilutz

bin/configs/rust-reqwest-petstore-serde-path-to-error.yaml

@@ -0,0 +1,10 @@
+generatorName: rust
+outputDir: samples/client/petstore/rust/reqwest/petstore-serde-path-to-error
+library: reqwest
+inputSpec: modules/openapi-generator/src/test/resources/3_0/rust/petstore.yaml
+templateDir: modules/openapi-generator/src/main/resources/rust
+additionalProperties:
+  packageName: petstore-reqwest-serde-path-to-error
+  useSerdePathToError: true
+enumNameMappings:
+  delivered: shipped

docs/generators/rust.md

@@ -34,6 +34,7 @@ These options may be applied as additional-properties (cli) or configOptions (pl
 |supportTokenSource|If set, add support for google-cloud-token. This option is for 'reqwest' and 'reqwest-trait' library only and requires the 'supportAsync' option| |false|
 |topLevelApiClient|Creates a top level `Api` trait and `ApiClient` struct that contain all Apis. This option is for 'reqwest-trait' library only| |false|
 |useBonBuilder|Use the bon crate for building parameter types. This option is for the 'reqwest-trait' library only| |false|
+|useSerdePathToError|If set, use the serde_path_to_error library to enhance serde error messages. This option is for 'reqwest' and 'reqwest-trait' library only| |false|
 |useSingleRequestParameter|Setting this property to true will generate functions with a single argument containing all API endpoint parameters instead of one argument per parameter.| |false|
 |withAWSV4Signature|whether to include AWS v4 signature support| |false|
 

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/RustClientCodegen.java

@@ -52,6 +52,7 @@ public class RustClientCodegen extends AbstractRustCodegen implements CodegenCon
     @Setter(AccessLevel.PRIVATE) private boolean useSingleRequestParameter = false;
     @Setter(AccessLevel.PRIVATE) private boolean supportAsync = true;
     @Setter(AccessLevel.PRIVATE) private boolean supportMiddleware = false;
+    @Setter(AccessLevel.PRIVATE) private boolean useSerdePathToError = false;
     @Setter(AccessLevel.PRIVATE) private boolean supportTokenSource = false;
     private boolean supportMultipleResponses = false;
     private boolean withAWSV4Signature = false;
@@ -70,6 +71,7 @@ public class RustClientCodegen extends AbstractRustCodegen implements CodegenCon
     public static final String REQWEST_TRAIT_LIBRARY_ATTR = "reqwestTrait";
     public static final String SUPPORT_ASYNC = "supportAsync";
     public static final String SUPPORT_MIDDLEWARE = "supportMiddleware";
+    public static final String USE_SERDE_PATH_TO_ERROR = "useSerdePathToError";
     public static final String SUPPORT_TOKEN_SOURCE = "supportTokenSource";
     public static final String SUPPORT_MULTIPLE_RESPONSES = "supportMultipleResponses";
     public static final String PREFER_UNSIGNED_INT = "preferUnsignedInt";
@@ -210,6 +212,8 @@ public RustClientCodegen() {
                 .defaultValue(Boolean.TRUE.toString()));
         cliOptions.add(new CliOption(SUPPORT_MIDDLEWARE, "If set, add support for reqwest-middleware. This option is for 'reqwest' and 'reqwest-trait' library only", SchemaTypeUtil.BOOLEAN_TYPE)
                 .defaultValue(Boolean.FALSE.toString()));
+        cliOptions.add(new CliOption(USE_SERDE_PATH_TO_ERROR, "If set, use the serde_path_to_error library to enhance serde error messages. This option is for 'reqwest' and 'reqwest-trait' library only", SchemaTypeUtil.BOOLEAN_TYPE)
+                .defaultValue(Boolean.FALSE.toString()));
         cliOptions.add(new CliOption(SUPPORT_TOKEN_SOURCE, "If set, add support for google-cloud-token. This option is for 'reqwest' and 'reqwest-trait' library only and requires the 'supportAsync' option", SchemaTypeUtil.BOOLEAN_TYPE)
                 .defaultValue(Boolean.FALSE.toString()));
         cliOptions.add(new CliOption(SUPPORT_MULTIPLE_RESPONSES, "If set, return type wraps an enum of all possible 2xx schemas. This option is for 'reqwest' and 'reqwest-trait' library only", SchemaTypeUtil.BOOLEAN_TYPE)
@@ -410,6 +414,11 @@ public void processOpts() {
         }
         writePropertyBack(SUPPORT_MIDDLEWARE, getSupportMiddleware());
 
+        if (additionalProperties.containsKey(USE_SERDE_PATH_TO_ERROR)) {
+            this.setUseSerdePathToError(convertPropertyToBoolean(USE_SERDE_PATH_TO_ERROR));
+        }
+        writePropertyBack(USE_SERDE_PATH_TO_ERROR, getUseSerdePathToError());
+
         if (additionalProperties.containsKey(SUPPORT_TOKEN_SOURCE)) {
             this.setSupportTokenSource(convertPropertyToBoolean(SUPPORT_TOKEN_SOURCE));
         }
@@ -527,6 +536,10 @@ private boolean getSupportMiddleware() {
         return supportMiddleware;
     }
 
+    private boolean getUseSerdePathToError() {
+        return useSerdePathToError;
+    }
+
     private boolean getSupportTokenSource() {
         return supportTokenSource;
     }

modules/openapi-generator/src/main/resources/rust/Cargo.mustache

@@ -38,6 +38,9 @@ serde_with = { version = "^3.8", default-features = false, features = ["base64",
 {{/serdeWith}}
 serde_json = "^1.0"
 serde_repr = "^0.1"
+{{#useSerdePathToError}}
+serde_path_to_error = "^0.1"
+{{/useSerdePathToError}}
 url = "^2.5"
 {{#hasUUIDs}}
 uuid = { version = "^1.8", features = ["serde", "v4"] }

modules/openapi-generator/src/main/resources/rust/reqwest-trait/api.mustache

@@ -488,7 +488,12 @@ impl {{classname}} for {{classname}}Client {
             {{/returnType}}
             {{#returnType}}
             match local_var_content_type {
+                {{^useSerdePathToError}}
                 ContentType::Json => serde_json::from_str(&local_var_content).map_err(Error::from),
+                {{/useSerdePathToError}}
+                {{#useSerdePathToError}}
+                ContentType::Json => serde_path_to_error::deserialize(&mut serde_json::Deserializer::from_str(&local_var_content)).map_err(Error::from),
+                {{/useSerdePathToError}}
                 {{#vendorExtensions.x-supports-plain-text}}
                 ContentType::Text => return Ok(local_var_content),
                 {{/vendorExtensions.x-supports-plain-text}}

modules/openapi-generator/src/main/resources/rust/reqwest/api.mustache

@@ -528,7 +528,12 @@ pub {{#supportAsync}}async {{/supportAsync}}fn {{{operationId}}}(configuration:
         {{#returnType}}
         let content = resp.text(){{#supportAsync}}.await{{/supportAsync}}?;
         match content_type {
+            {{^useSerdePathToError}}
             ContentType::Json => serde_json::from_str(&content).map_err(Error::from),
+            {{/useSerdePathToError}}
+            {{#useSerdePathToError}}
+            ContentType::Json => serde_path_to_error::deserialize(&mut serde_json::Deserializer::from_str(&content)).map_err(Error::from),
+            {{/useSerdePathToError}}
             {{#vendorExtensions.x-supports-plain-text}}
             ContentType::Text => return Ok(content),
             {{/vendorExtensions.x-supports-plain-text}}

modules/openapi-generator/src/main/resources/rust/reqwest/api_mod.mustache

@@ -18,6 +18,9 @@ pub enum Error<T> {
     ReqwestMiddleware(reqwest_middleware::Error),
     {{/supportMiddleware}}
     Serde(serde_json::Error),
+    {{#useSerdePathToError}}
+    SerdePathToError(serde_path_to_error::Error<serde_json::Error>),
+    {{/useSerdePathToError}}
     Io(std::io::Error),
     ResponseError(ResponseContent<T>),
     {{#withAWSV4Signature}}
@@ -38,6 +41,9 @@ impl <T> fmt::Display for Error<T> {
             Error::ReqwestMiddleware(e) => ("reqwest-middleware", e.to_string()),
             {{/supportMiddleware}}
             Error::Serde(e) => ("serde", e.to_string()),
+            {{#useSerdePathToError}}
+            Error::SerdePathToError(e) => ("serde", format!("{}: {}", e.path().to_string(), e.inner().to_string())),
+            {{/useSerdePathToError}}
             Error::Io(e) => ("IO", e.to_string()),
             Error::ResponseError(e) => ("response", format!("status code {}", e.status)),
             {{#withAWSV4Signature}}
@@ -61,6 +67,9 @@ impl <T: fmt::Debug> error::Error for Error<T> {
             Error::ReqwestMiddleware(e) => e,
             {{/supportMiddleware}}
             Error::Serde(e) => e,
+            {{#useSerdePathToError}}
+            Error::SerdePathToError(e) => e,
+            {{/useSerdePathToError}}
             Error::Io(e) => e,
             Error::ResponseError(_) => return None,
             {{#withAWSV4Signature}}
@@ -95,6 +104,14 @@ impl <T> From<serde_json::Error> for Error<T> {
     }
 }
 
+{{#useSerdePathToError}}
+impl<T> From<serde_path_to_error::Error<serde_json::Error>> for Error<T> {
+    fn from(e: serde_path_to_error::Error<serde_json::Error>) -> Self {
+        Error::SerdePathToError(e)
+    }
+}
+
+{{/useSerdePathToError}}
 impl <T> From<std::io::Error> for Error<T> {
     fn from(e: std::io::Error) -> Self {
         Error::Io(e)

samples/client/petstore/rust/reqwest/petstore-serde-path-to-error/.gitignore

@@ -0,0 +1,3 @@
+/target/
+**/*.rs.bk
+Cargo.lock

samples/client/petstore/rust/reqwest/petstore-serde-path-to-error/.openapi-generator-ignore

@@ -0,0 +1,23 @@
+# OpenAPI Generator Ignore
+# Generated by openapi-generator https://github.com/openapitools/openapi-generator
+
+# Use this file to prevent files from being overwritten by the generator.
+# The patterns follow closely to .gitignore or .dockerignore.
+
+# As an example, the C# client generator defines ApiClient.cs.
+# You can make changes and tell OpenAPI Generator to ignore just this file by uncommenting the following line:
+#ApiClient.cs
+
+# You can match any string of characters against a directory, file or extension with a single asterisk (*):
+#foo/*/qux
+# The above matches foo/bar/qux and foo/baz/qux, but not foo/bar/baz/qux
+
+# You can recursively match patterns against a directory, file or extension with a double asterisk (**):
+#foo/**/qux
+# This matches foo/bar/qux, foo/baz/qux, and foo/bar/baz/qux
+
+# You can also negate patterns with an exclamation (!).
+# For example, you can ignore all files in a docs folder with the file extension .md:
+#docs/*.md
+# Then explicitly reverse the ignore rule for a single file:
+#!docs/README.md

samples/client/petstore/rust/reqwest/petstore-serde-path-to-error/.openapi-generator/FILES

@@ -0,0 +1,67 @@
+.gitignore
+.travis.yml
+Cargo.toml
+README.md
+docs/ActionContainer.md
+docs/AnyTypeTest.md
+docs/ApiResponse.md
+docs/ArrayItemRefTest.md
+docs/Baz.md
+docs/Category.md
+docs/EnumArrayTesting.md
+docs/FakeApi.md
+docs/NullableArray.md
+docs/NumericEnumTesting.md
+docs/OptionalTesting.md
+docs/Order.md
+docs/Page.md
+docs/Person.md
+docs/Pet.md
+docs/PetApi.md
+docs/PropertyTest.md
+docs/Ref.md
+docs/Return.md
+docs/StoreApi.md
+docs/Tag.md
+docs/TestAllOfWithMultiMetadataOnly.md
+docs/TestingApi.md
+docs/TypeTesting.md
+docs/UniqueItemArrayTesting.md
+docs/User.md
+docs/UserApi.md
+docs/Vehicle.md
+docs/WithInnerOneOf.md
+git_push.sh
+src/apis/configuration.rs
+src/apis/fake_api.rs
+src/apis/mod.rs
+src/apis/pet_api.rs
+src/apis/store_api.rs
+src/apis/testing_api.rs
+src/apis/user_api.rs
+src/lib.rs
+src/models/action_container.rs
+src/models/any_type_test.rs
+src/models/api_response.rs
+src/models/array_item_ref_test.rs
+src/models/baz.rs
+src/models/category.rs
+src/models/enum_array_testing.rs
+src/models/mod.rs
+src/models/model_ref.rs
+src/models/model_return.rs
+src/models/nullable_array.rs
+src/models/numeric_enum_testing.rs
+src/models/optional_testing.rs
+src/models/order.rs
+src/models/page.rs
+src/models/person.rs
+src/models/pet.rs
+src/models/property_test.rs
+src/models/tag.rs
+src/models/test_all_of_with_multi_metadata_only.rs
+src/models/type_testing.rs
+src/models/unique_item_array_testing.rs
+src/models/user.rs
+src/models/vehicle.rs
+src/models/with_inner_one_of.rs