[Rust Server] Don't change API version (#5458)

Don't change the API version which is exposed in `crate::API_VERSION`.

- If the API version isn't set, we don't expose it.

- If it is set, we leave it well alone.

- Always pass a package version:
 - Pass in the passed package version by preference
 - Pass in the API version if it's not.
   - If the API version isn't set, we use 1.0.0
   - If it is set, and isn't a valid semver, we append .0 such that we have
     something with three digits (so that an API version of 1 works).

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

@@ -268,7 +268,6 @@ public void processOpts() {
         additionalProperties.put("modelDocPath", modelDocPath);
 
         additionalProperties.put(CodegenConstants.PACKAGE_NAME, packageName);
-        additionalProperties.put(CodegenConstants.PACKAGE_VERSION, packageVersion);
         additionalProperties.put("externCrateName", externCrateName);
     }
 
@@ -323,19 +322,26 @@ public String getHelp() {
 
     @Override
     public void preprocessOpenAPI(OpenAPI openAPI) {
+
         Info info = openAPI.getInfo();
-        List<String> versionComponents = new ArrayList<>(Arrays.asList(info.getVersion().split("[.]")));
-        if (versionComponents.size() < 1) {
-            versionComponents.add("1");
-        }
-        while (versionComponents.size() < 3) {
-            versionComponents.add("0");
-        }
-        info.setVersion(StringUtils.join(versionComponents, "."));
 
         URL url = URLPathUtils.getServerURL(openAPI, serverVariableOverrides());
         additionalProperties.put("serverHost", url.getHost());
         additionalProperties.put("serverPort", URLPathUtils.getPort(url, 80));
+
+        if (packageVersion == null || "".equals(packageVersion)) {
+            List<String> versionComponents = new ArrayList<>(Arrays.asList(info.getVersion().split("[.]")));
+            if (versionComponents.size() < 1) {
+                versionComponents.add("1");
+            }
+            while (versionComponents.size() < 3) {
+                versionComponents.add("0");
+            }
+
+            setPackageVersion(StringUtils.join(versionComponents, "."));
+        }
+
+        additionalProperties.put(CodegenConstants.PACKAGE_VERSION, packageVersion);
     }
 
     @Override

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

@@ -1,6 +1,6 @@
 [package]
 name = "{{{packageName}}}"
-version = {{#packageVersion}}"{{{packageVersion}}}"{{/packageVersion}}{{^packageVersion}}"{{{appVersion}}}"{{/packageVersion}}{{! Fill in with packageVersion if defined, which can be passed via a command line argument, Else use appVersion from the Open API spec, which defaults to 1.0.0 if not present.}}
+version = "{{{packageVersion}}}"
 authors = [{{#infoEmail}}"{{{infoEmail}}}"{{/infoEmail}}]
 {{#appDescription}}
 description = "{{{appDescription}}}"

modules/openapi-generator/src/main/resources/rust-server/lib.mustache

@@ -88,7 +88,9 @@ pub use swagger::{ApiError, ContextWrapper};
 pub use futures::Future;
 
 pub const BASE_PATH: &'static str = "{{{basePathWithoutHost}}}";
+{{#appVersion}}
 pub const API_VERSION: &'static str = "{{{appVersion}}}";
+{{/appVersion}}
 
 {{#apiInfo}}{{#apis}}{{#operations}}{{#operation}}
 #[derive(Debug, PartialEq)]