add separate command for merging openapi specs

Author: nicoburniske

src/lib.rs

@@ -18,11 +18,13 @@ use openapiv3::OpenAPI;
 use std::path::Path;
 use std::result;
 
-mod merger;
+pub(crate) mod merger;
 pub(crate) mod printer;
 mod rust;
 mod toml;
 
+pub use merger::merge_all_openapi_specs;
+
 #[derive(Debug, Clone)]
 pub enum Error {
     Unexpected { message: String },
@@ -56,7 +58,7 @@ impl Error {
 pub type Result<T> = result::Result<T, Error>;
 
 pub fn gen(openapi_specs: Vec<OpenAPI>, target: &Path, name: &str, version: &str) -> Result<()> {
-    let open_api = merger::merge_all_openapi_specs(openapi_specs)?;
+    let open_api = merge_all_openapi_specs(openapi_specs)?;
 
     let src = target.join("src");
     let api = src.join("api");

src/main.rs

@@ -12,7 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-use clap::Parser;
+use clap::{Args, Parser};
 use golem_openapi_client_generator::gen;
 use openapiv3::OpenAPI;
 use std::fs::File;
@@ -21,7 +21,15 @@ use std::path::PathBuf;
 
 #[derive(Parser, Debug)]
 #[command(author, version, about, long_about = None, rename_all = "kebab-case")]
-struct Command {
+enum Cli {
+    /// Generate a client from an OpenAPI spec
+    Generate(GenerateArgs),
+    /// Merge multiple OpenAPI specs into a single one
+    Merge(MergeArgs),
+}
+
+#[derive(Debug, Args)]
+struct GenerateArgs {
     #[arg(short, long, value_name = "spec", value_hint = clap::ValueHint::FilePath, num_args = 1.., required = true)]
     spec_yaml: Vec<PathBuf>,
 
@@ -35,26 +43,46 @@ struct Command {
     name: String,
 }
 
+#[derive(Debug, Args)]
+struct MergeArgs {
+    #[arg(short, long, value_name = "specs", value_hint = clap::ValueHint::FilePath, num_args = 1.., required = true)]
+    spec_yaml: Vec<PathBuf>,
+    #[arg(short, long, value_name = "output", value_hint = clap::ValueHint::FilePath)]
+    output_file: PathBuf,
+}
+
 fn main() {
-    let command = Command::parse();
+    let command = Cli::parse();
+
+    match command {
+        Cli::Generate(args) => {
+            let openapi_specs = parse_openapi_specs(&args.spec_yaml);
+            gen(
+                openapi_specs,
+                &args.output_directory,
+                &args.name,
+                &args.client_version,
+            )
+            .unwrap();
+        }
+        Cli::Merge(args) => {
+            let openapi_specs = parse_openapi_specs(&args.spec_yaml);
+            let openapi =
+                golem_openapi_client_generator::merge_all_openapi_specs(openapi_specs).unwrap();
+            let file = File::create(&args.output_file).unwrap();
+            serde_yaml::to_writer(file, &openapi).unwrap();
+        }
+    }
+}
 
-    let openapi_specs = command
-        .spec_yaml
-        .into_iter()
+fn parse_openapi_specs(spec: &Vec<PathBuf>) -> Vec<OpenAPI> {
+    spec.into_iter()
         .map(|spec| {
             let file = File::open(&spec).unwrap();
             let reader = BufReader::new(file);
             let openapi: OpenAPI = serde_yaml::from_reader(reader)
                 .expect(format!("Could not deserialize input: {:?}", spec).as_str());
             openapi
         })
-        .collect::<Vec<_>>();
-
-    gen(
-        openapi_specs,
-        &command.output_directory,
-        &command.name,
-        &command.client_version,
-    )
-    .unwrap();
+        .collect::<Vec<_>>()
 }

src/merger.rs

@@ -4,7 +4,7 @@ use openapiv3::{Components, ExternalDocumentation, OpenAPI, Paths};
 use crate::Error;
 use crate::Result;
 
-pub(crate) fn merge_all_openapi_specs(openapi_specs: Vec<OpenAPI>) -> Result<OpenAPI> {
+pub fn merge_all_openapi_specs(openapi_specs: Vec<OpenAPI>) -> Result<OpenAPI> {
     if openapi_specs.is_empty() {
         Err(Error::unexpected("No OpenAPI specs provided"))
     } else if openapi_specs.len() == 1 {
@@ -46,10 +46,19 @@ fn merge_openapi_specs(a: OpenAPI, b: OpenAPI) -> Result<OpenAPI> {
     };
 
     let all_tags = {
-        let mut tags = a.tags;
-        let mut b_tags = b.tags;
-        tags.append(&mut b_tags);
-        tags
+        let a_tags_map = a
+            .tags
+            .into_iter()
+            .map(|tag| (tag.name.clone(), tag))
+            .collect::<IndexMap<_, _>>();
+        let b_tags_map = b
+            .tags
+            .into_iter()
+            .map(|tag| (tag.name.clone(), tag))
+            .collect::<IndexMap<_, _>>();
+        let merged = merge_unique(a_tags_map, b_tags_map)?;
+
+        merged.into_values().collect::<Vec<_>>()
     };
 
     let all_paths = {