[Rust] set supportAsync to true as the default (#6480)

* set supportAsync to true

* set reqwest as the default lib

Author: wing328

bin/rust-petstore.sh

@@ -40,7 +40,7 @@ for spec_path in \
                    --input-spec $spec_path
                    --generator-name rust
                    --output samples/client/petstore/rust/$library/$spec
-                   --additional-properties packageName=${spec}-${library}
+                   --additional-properties packageName=${spec}-${library},supportAsync=false
                    --library=$library $@"
     java ${JAVA_OPTS} -jar ${executable} ${args} || exit 1
   done

docs/generators/rust.md

@@ -6,10 +6,10 @@ sidebar_label: rust
 | Option | Description | Values | Default |
 | ------ | ----------- | ------ | ------- |
 |hideGenerationTimestamp|Hides the generation timestamp when files are generated.| |true|
-|library|library template (sub-template) to use.|<dl><dt>**hyper**</dt><dd>HTTP client: Hyper.</dd><dt>**reqwest**</dt><dd>HTTP client: Reqwest.</dd></dl>|hyper|
+|library|library template (sub-template) to use.|<dl><dt>**hyper**</dt><dd>HTTP client: Hyper.</dd><dt>**reqwest**</dt><dd>HTTP client: Reqwest.</dd></dl>|reqwest|
 |packageName|Rust package name (convention: lowercase).| |openapi|
 |packageVersion|Rust package version.| |1.0.0|
-|supportAsync|If set, generate async function call instead| |false|
+|supportAsync|If set, generate async function call instead. This option is for 'reqwest' library only| |true|
 |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|
 
 ## IMPORT MAPPING

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

@@ -39,7 +39,7 @@
 public class RustClientCodegen extends DefaultCodegen implements CodegenConfig {
     private static final Logger LOGGER = LoggerFactory.getLogger(RustClientCodegen.class);
     private boolean useSingleRequestParameter = false;
-    private boolean supportAsync = false;
+    private boolean supportAsync = true;
 
     public static final String PACKAGE_NAME = "packageName";
     public static final String PACKAGE_VERSION = "packageVersion";
@@ -173,18 +173,18 @@ public RustClientCodegen() {
                 .defaultValue(Boolean.TRUE.toString()));
         cliOptions.add(new CliOption(CodegenConstants.USE_SINGLE_REQUEST_PARAMETER, CodegenConstants.USE_SINGLE_REQUEST_PARAMETER_DESC, SchemaTypeUtil.BOOLEAN_TYPE)
                 .defaultValue(Boolean.FALSE.toString()));
-        cliOptions.add(new CliOption(SUPPORT_ASYNC, "If set, generate async function call instead", SchemaTypeUtil.BOOLEAN_TYPE)
-                .defaultValue(Boolean.FALSE.toString()));
+        cliOptions.add(new CliOption(SUPPORT_ASYNC, "If set, generate async function call instead. This option is for 'reqwest' library only", SchemaTypeUtil.BOOLEAN_TYPE)
+                .defaultValue(Boolean.TRUE.toString()));
 
         supportedLibraries.put(HYPER_LIBRARY, "HTTP client: Hyper.");
         supportedLibraries.put(REQWEST_LIBRARY, "HTTP client: Reqwest.");
 
         CliOption libraryOption = new CliOption(CodegenConstants.LIBRARY, "library template (sub-template) to use.");
         libraryOption.setEnum(supportedLibraries);
-        // set hyper as the default
-        libraryOption.setDefault(HYPER_LIBRARY);
+        // set reqwest as the default
+        libraryOption.setDefault(REQWEST_LIBRARY);
         cliOptions.add(libraryOption);
-        setLibrary(HYPER_LIBRARY);
+        setLibrary(REQWEST_LIBRARY);
     }
 
     @Override