fix(cli): operation response type exhaustive

Add support for multiple response types in the generated client, including handling JSON deserializable types, empty bodies, streams of bytes, and upgraded connections.

This change addresses the following issues:
- Multiple response types not supported (#344)
- Path to GitHub client (#395)

.gitignore

@@ -1,3 +1,4 @@
 target/
-
+.idea/
+.env
 progenitor-impl/tests/output/Cargo.lock

Cargo.lock

@@ -132,7 +132,7 @@ checksum = "16e62a023e7c117e27523144c5d2459f4397fcc3cab0085af8e2224f643a0193"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn 2.0.68",
+ "syn 2.0.69",
 ]
 
 [[package]]
@@ -143,7 +143,7 @@ checksum = "c6fa2087f2753a7da8cc1c0dbfcf89579dd57458e36769de5ac750b4671737ca"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn 2.0.68",
+ "syn 2.0.69",
 ]
 
 [[package]]
@@ -208,9 +208,9 @@ dependencies = [
 
 [[package]]
 name = "built"
-version = "0.7.3"
+version = "0.7.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c6a6c0b39c38fd754ac338b00a88066436389c0f029da5d37d1e01091d9b7c17"
+checksum = "236e6289eda5a812bc6b53c3b024039382a2895fbbeef2d748b2931546d392c4"
 dependencies = [
  "cargo-lock",
  "git2",
@@ -329,7 +329,7 @@ dependencies = [
  "heck",
  "proc-macro2",
  "quote",
- "syn 2.0.68",
+ "syn 2.0.69",
 ]
 
 [[package]]
@@ -471,7 +471,7 @@ dependencies = [
 [[package]]
 name = "dropshot"
 version = "0.10.2-dev"
-source = "git+https://github.com/oxidecomputer/dropshot#d3e7ac6886ad2b65c05aa2730e1f0714661711f4"
+source = "git+https://github.com/oxidecomputer/dropshot#6a3f84ca5fd8d0c5c010cfe837efbe6b5d117d9d"
 dependencies = [
  "async-stream",
  "async-trait",
@@ -516,13 +516,14 @@ dependencies = [
 [[package]]
 name = "dropshot_endpoint"
 version = "0.10.2-dev"
-source = "git+https://github.com/oxidecomputer/dropshot#d3e7ac6886ad2b65c05aa2730e1f0714661711f4"
+source = "git+https://github.com/oxidecomputer/dropshot#6a3f84ca5fd8d0c5c010cfe837efbe6b5d117d9d"
 dependencies = [
+ "heck",
  "proc-macro2",
  "quote",
  "serde",
  "serde_tokenstream",
- "syn 2.0.68",
+ "syn 2.0.69",
 ]
 
 [[package]]
@@ -599,7 +600,7 @@ dependencies = [
  "reqwest",
  "serde",
  "serde_json",
- "syn 2.0.68",
+ "syn 2.0.69",
  "uuid",
 ]
 
@@ -627,7 +628,7 @@ dependencies = [
  "reqwest",
  "serde",
  "serde_json",
- "syn 2.0.68",
+ "syn 2.0.69",
  "uuid",
  "wasm-bindgen-test",
 ]
@@ -735,7 +736,7 @@ checksum = "87750cf4b7a4c0625b1529e4c543c2182106e4dedc60a2a6455e00d212c489ac"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn 2.0.68",
+ "syn 2.0.69",
 ]
 
 [[package]]
@@ -799,9 +800,9 @@ checksum = "b6c80984affa11d98d1b88b66ac8853f143217b399d3c74116778ff8fdb4ed2e"
 
 [[package]]
 name = "git2"
-version = "0.18.1"
+version = "0.19.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "fbf97ba92db08df386e10c8ede66a2a0369bd277090afd8710e19e38de9ec0cd"
+checksum = "b903b73e45dc0c6c596f2d37eccece7c1c8bb6e4407b001096387c63d0d93724"
 dependencies = [
  "bitflags 2.4.0",
  "libc",
@@ -944,9 +945,9 @@ checksum = "9a3a5bfb195931eeb336b2a7b4d761daec841b97f947d34394601737a7bba5e4"
 
 [[package]]
 name = "hyper"
-version = "0.14.27"
+version = "0.14.29"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ffb1cfd654a8219eaef89881fdb3bb3b1cdc5fa75ded05d6933b2b382e395468"
+checksum = "f361cde2f109281a220d4307746cdfd5ee3f410da58a70377762396775634b33"
 dependencies = [
  "bytes",
  "futures-channel",
@@ -959,7 +960,7 @@ dependencies = [
  "httpdate",
  "itoa",
  "pin-project-lite",
- "socket2 0.4.9",
+ "socket2",
  "tokio",
  "tower-service",
  "tracing",
@@ -1070,9 +1071,9 @@ checksum = "89d92a4743f9a61002fae18374ed11e7973f530cb3a3255fb354818118b2203c"
 
 [[package]]
 name = "libgit2-sys"
-version = "0.16.2+1.7.2"
+version = "0.17.0+1.8.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ee4126d8b4ee5c9d9ea891dd875cfdc1e9d0950437179104b183d7d8a74d24e8"
+checksum = "10472326a8a6477c3c20a64547b0059e4b0d086869eee31e6d7da728a8eb7224"
 dependencies = [
  "cc",
  "libc",
@@ -1371,7 +1372,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "5f12335488a2f3b0a83b14edad48dca9879ce89b2edd10e80237e4e852dd645e"
 dependencies = [
  "proc-macro2",
- "syn 2.0.68",
+ "syn 2.0.69",
 ]
 
 [[package]]
@@ -1439,7 +1440,7 @@ dependencies = [
  "serde",
  "serde_json",
  "serde_yaml",
- "syn 2.0.68",
+ "syn 2.0.69",
  "thiserror",
  "tokio",
  "typify",
@@ -1459,7 +1460,7 @@ dependencies = [
  "serde_json",
  "serde_tokenstream",
  "serde_yaml",
- "syn 2.0.68",
+ "syn 2.0.69",
 ]
 
 [[package]]
@@ -1766,7 +1767,7 @@ dependencies = [
  "proc-macro2",
  "quote",
  "serde_derive_internals",
- "syn 2.0.68",
+ "syn 2.0.69",
 ]
 
 [[package]]
@@ -1815,22 +1816,22 @@ dependencies = [
 
 [[package]]
 name = "serde"
-version = "1.0.203"
+version = "1.0.204"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7253ab4de971e72fb7be983802300c30b5a7f0c2e56fab8abfc6a214307c0094"
+checksum = "bc76f558e0cbb2a839d37354c575f1dc3fdc6546b5be373ba43d95f231bf7c12"
 dependencies = [
  "serde_derive",
 ]
 
 [[package]]
 name = "serde_derive"
-version = "1.0.203"
+version = "1.0.204"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "500cbc0ebeb6f46627f50f3f5811ccf6bf00643be300b4c3eabc0ef55dc5b5ba"
+checksum = "e0cd7e117be63d3c3678776753929474f3b04a43a080c744d6b0ae2a8c28e222"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn 2.0.68",
+ "syn 2.0.69",
 ]
 
 [[package]]
@@ -1841,14 +1842,14 @@ checksum = "330f01ce65a3a5fe59a60c82f3c9a024b573b8a6e875bd233fe5f934e71d54e3"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn 2.0.68",
+ "syn 2.0.69",
 ]
 
 [[package]]
 name = "serde_json"
-version = "1.0.117"
+version = "1.0.119"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "455182ea6142b14f93f4bc5320a2b31c1f266b66a4a5c858b013302a5d8cbfc3"
+checksum = "e8eddb61f0697cc3989c5d64b452f5488e2b8a60fd7d5076a3045076ffef8cb0"
 dependencies = [
  "itoa",
  "ryu",
@@ -1883,7 +1884,7 @@ dependencies = [
  "proc-macro2",
  "quote",
  "serde",
- "syn 2.0.68",
+ "syn 2.0.69",
 ]
 
 [[package]]
@@ -2004,16 +2005,6 @@ version = "1.13.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "3c5e1a9a646d36c3599cd173a41282daf47c44583ad367b8e6837255952e5c67"
 
-[[package]]
-name = "socket2"
-version = "0.4.9"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "64a4a911eed85daf18834cfaa86a79b7d266ff93ff5ba14005426219480ed662"
-dependencies = [
- "libc",
- "winapi",
-]
-
 [[package]]
 name = "socket2"
 version = "0.5.5"
@@ -2055,9 +2046,9 @@ dependencies = [
 
 [[package]]
 name = "syn"
-version = "2.0.68"
+version = "2.0.69"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "901fa70d88b9d6c98022e23b4136f9f3e54e4662c3bc1bd1d84a42a9a0f0c1e9"
+checksum = "201fcda3845c23e8212cd466bfebf0bd20694490fc0356ae8e428e0824a915a6"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -2147,7 +2138,7 @@ checksum = "46c3384250002a6d5af4d114f2845d37b57521033f30d5c3f46c4d70e1197533"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn 2.0.68",
+ "syn 2.0.69",
 ]
 
 [[package]]
@@ -2219,7 +2210,7 @@ dependencies = [
  "parking_lot",
  "pin-project-lite",
  "signal-hook-registry",
- "socket2 0.5.5",
+ "socket2",
  "tokio-macros",
  "windows-sys 0.48.0",
 ]
@@ -2232,7 +2223,7 @@ checksum = "5f5ae998a069d4b5aba8ee9dad856af7d520c3699e6159b185c2acd48155d39a"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn 2.0.68",
+ "syn 2.0.69",
 ]
 
 [[package]]
@@ -2402,7 +2393,7 @@ dependencies = [
  "semver",
  "serde",
  "serde_json",
- "syn 2.0.68",
+ "syn 2.0.69",
  "thiserror",
  "unicode-ident",
 ]
@@ -2419,7 +2410,7 @@ dependencies = [
  "serde",
  "serde_json",
  "serde_tokenstream",
- "syn 2.0.68",
+ "syn 2.0.69",
  "typify-impl",
 ]
 
@@ -2566,7 +2557,7 @@ dependencies = [
  "once_cell",
  "proc-macro2",
  "quote",
- "syn 2.0.68",
+ "syn 2.0.69",
  "wasm-bindgen-shared",
 ]
 
@@ -2600,7 +2591,7 @@ checksum = "e94f17b526d0a461a191c78ea52bbce64071ed5c04c9ffe424dcb38f74171bb7"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn 2.0.68",
+ "syn 2.0.69",
  "wasm-bindgen-backend",
  "wasm-bindgen-shared",
 ]
@@ -2633,7 +2624,7 @@ checksum = "b7f89739351a2e03cb94beb799d47fb2cac01759b40ec441f7de39b00cbf7ef0"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn 2.0.68",
+ "syn 2.0.69",
 ]
 
 [[package]]
@@ -2986,7 +2977,7 @@ checksum = "9ce1b18ccd8e73a9321186f97e46f9f04b778851177567b1975109d26a08d2a6"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn 2.0.68",
+ "syn 2.0.69",
 ]
 
 [[package]]

Cargo.toml

@@ -20,7 +20,7 @@ progenitor-macro = { version = "0.7.0", path = "progenitor-macro" }
 
 anyhow = "1.0.86"
 base64 = "0.22.1"
-built = { version = "0.7.3", features = ["cargo-lock", "git2"] }
+built = { version = "0.7.4", features = ["cargo-lock", "git2"] }
 bytes = "1.6.0"
 chrono = { version = "0.4.0", features = ["serde"] }
 clap = { version = "4.5.8", features = ["derive"] }
@@ -31,7 +31,7 @@ futures = "0.3.30"
 futures-core = "0.3.30"
 heck = "0.5.0"
 http = "0.2.9"
-hyper = "0.14.27"
+hyper = "0.14.29"
 indexmap = "2.2.6"
 openapiv3 = "2.0.0"
 percent-encoding = "2.3.0"
@@ -44,11 +44,11 @@ regress = "0.10.0"
 reqwest = { version = "0.11.27", features = ["json", "stream"] }
 rustfmt-wrapper = "0.2.1"
 schemars = { version = "0.8.21", features = ["chrono", "uuid1"] }
-serde = { version = "1.0.203", features = ["derive"] }
+serde = { version = "1.0.204", features = ["derive"] }
-serde_json = "1.0.117"
+serde_json = "1.0.119"
 serde_urlencoded = "0.7.1"
 serde_yaml = "0.9"
-syn = { version = "2.0.68", features = ["parsing"] }
+syn = { version = "2.0.69", features = ["parsing"] }
 thiserror = "1.0.61"
 tokio = { version = "1.38.0", features = ["rt", "net"] }
 # change when publishing

progenitor-client/src/progenitor_client.rs

@@ -78,6 +78,18 @@ impl<T: DeserializeOwned> ResponseValue<T> {
             headers,
         })
     }
+
+    /// Transforms the inner data of this `ResponseValue` using a provided function, returning a new `ResponseValue` with the transformed data.
+    pub fn map_inner<U, F>(self, op: F) -> ResponseValue<U>
+    where
+        F: FnOnce(T) -> U,
+    {
+        ResponseValue {
+            inner: op(self.inner), // Apply the operation to the inner data
+            status: self.status,  // Preserve the status
+            headers: self.headers, // Preserve the headers
+        }
+    }
 }
 
 #[cfg(not(target_arch = "wasm32"))]

progenitor-impl/src/cli.rs

@@ -259,6 +259,7 @@ impl Generator {
                         }
                     }
                     crate::method::OperationResponseKind::Raw
+                    | crate::method::OperationResponseKind::Multi(_)
                     | crate::method::OperationResponseKind::Upgrade => {
                         quote! {
                             {
@@ -279,6 +280,7 @@ impl Generator {
                         }
                     }
                     crate::method::OperationResponseKind::Raw
+                    | crate::method::OperationResponseKind::Multi(_)
                     | crate::method::OperationResponseKind::Upgrade => {
                         quote! {
                             {
@@ -306,6 +308,7 @@ impl Generator {
                     }
                     crate::method::OperationResponseKind::None => quote! { () },
                     crate::method::OperationResponseKind::Raw => todo!(),
+                    crate::method::OperationResponseKind::Multi(_) => todo!(),
                     crate::method::OperationResponseKind::Upgrade => todo!(),
                 };
                 let error_output = match error_kind {
@@ -319,6 +322,7 @@ impl Generator {
                         }
                     }
                     crate::method::OperationResponseKind::Raw
+                    | crate::method::OperationResponseKind::Multi(_)
                     | crate::method::OperationResponseKind::Upgrade => {
                         quote! {
                             {
@@ -512,10 +516,10 @@ impl Generator {
             CliBodyArg::Required => Some(true),
             CliBodyArg::Optional => Some(false),
         })
-        .map(|required| {
+            .map(|required| {
-            let help = "Path to a file that contains the full json body.";
+                let help = "Path to a file that contains the full json body.";
 
-            quote! {
+                quote! {
                 .arg(
                     clap::Arg::new("json-body")
                         .long("json-body")
@@ -533,7 +537,7 @@ impl Generator {
                         .help("XXX")
                 )
             }
-        });
+            });
 
         let parser = quote! {
             #(

progenitor-impl/src/httpmock.rs

@@ -16,6 +16,7 @@ use crate::{
     util::{sanitize, Case},
     validate_openapi, Generator, Result,
 };
+use crate::util::generate_multi_type_identifier;
 
 struct MockOp {
     when: TokenStream,
@@ -313,6 +314,18 @@ impl Generator {
                             },
                         )
                     }
+                    crate::method::OperationResponseKind::Multi(types) => {
+                        let arg_type = generate_multi_type_identifier(types, &self.type_space);
+                        (
+                            quote! {
+                                value: #arg_type,
+                            },
+                            quote! {
+                                .header("content-type", "application/json")
+                                .json_body_obj(value)
+                            },
+                        )
+                    }
                     crate::method::OperationResponseKind::None => {
                         Default::default()
                     }

progenitor-impl/src/lib.rs

@@ -357,6 +357,7 @@ impl Generator {
         }?;
 
         let types = self.type_space.to_stream();
+        let multi_types = self.generate_multi_types_stream(&raw_methods, &self.type_space);
 
         // Generate an implementation of a `Self::as_inner` method, if an inner
         // type is defined.
@@ -427,6 +428,7 @@ impl Generator {
                 use std::convert::TryFrom;
 
                 #types
+                #multi_types
             }
 
             #[derive(Clone, Debug)]

progenitor-impl/src/method.rs

@@ -11,11 +11,11 @@ use proc_macro2::TokenStream;
 use quote::{format_ident, quote, ToTokens};
 use typify::{TypeId, TypeSpace};
 
-use crate::{
+use crate::{Error, Generator, method, Result, TagStyle, template::PathTemplate, util::{
-    template::PathTemplate,
+    Case, generate_multi_type_for_types_stream, generate_multi_type_identifier, items, parameter_map,
-    util::{items, parameter_map, sanitize, unique_ident_from, Case},
+    sanitize,
-    Error, Generator, Result, TagStyle,
+    unique_ident_from,
-};
+}};
 use crate::{to_schema::ToSchema, util::ReferenceOrExt};
 
 /// The intermediate representation of an operation that will become a method.
@@ -262,6 +262,7 @@ pub(crate) enum OperationResponseKind {
     None,
     Raw,
     Upgrade,
+    Multi(Vec<Box<OperationResponseKind>>),
 }
 
 impl OperationResponseKind {
@@ -280,6 +281,10 @@ impl OperationResponseKind {
             OperationResponseKind::Upgrade => {
                 quote! { reqwest::Upgraded }
             }
+            OperationResponseKind::Multi(ref types) => {
+                let type_name = generate_multi_type_identifier(types, type_space);
+                quote! { types::#type_name }
+            }
         }
     }
 }
@@ -1032,9 +1037,22 @@ impl Generator {
                             ResponseValue::upgrade(#response_ident).await
                         }
                     }
+                    OperationResponseKind::Multi(_) => {
+                        panic!("Shouldn't occur for the original response")
+                    }
                 };
 
-                quote! { #pat => { #decode } }
+                match &response_type {
+                    OperationResponseKind::Multi(types) => {
+                        let multi_type_name = generate_multi_type_identifier(
+                            &types,
+                            &self.type_space,
+                        );
+                        let type_name = &response.typ.clone().into_tokens(&self.type_space);
+                        quote! { #pat => { #decode.map(|v: ResponseValue<#type_name>| v.map_inner(types::#multi_type_name::from)) } }
+                    }
+                    _ => { quote! { #pat => { #decode } } }
+                }
             });
 
         // Errors...
@@ -1095,9 +1113,22 @@ impl Generator {
                             );
                         }
                     }
+                    OperationResponseKind::Multi(_) => {
+                        panic!("Shouldn't occur for the original response")
+                    }
                 };
 
-                quote! { #pat => { #decode } }
+                match &response_type {
+                    OperationResponseKind::Multi(types) => {
+                        let multi_type_name = generate_multi_type_identifier(
+                            &types,
+                            &self.type_space,
+                        );
+                        let type_name = &response.typ.clone().into_tokens(&self.type_space);
+                        quote! { #pat => { #decode.map(|v: ResponseValue<#type_name>| v.map_inner(types::#multi_type_name::from)) } }
+                    }
+                    _ => { quote! { #pat => { #decode } } }
+                }
             });
 
         let accept_header = matches!(
@@ -1218,6 +1249,29 @@ impl Generator {
         })
     }
 
+    pub(crate) fn generate_multi_types_stream(
+        &self,
+        input_methods: &[method::OperationMethod],
+        type_space: &TypeSpace) -> TokenStream {
+        let mut streams = Vec::new();
+
+        for method in input_methods {
+            let (success_response_items, response_type) = self.extract_responses(
+                method,
+                method::OperationResponseStatus::is_success_or_default,
+            );
+
+            if let OperationResponseKind::Multi(types) = response_type {
+                let multi_stream = generate_multi_type_for_types_stream(&types, type_space);
+                streams.push(multi_stream);
+            }
+        }
+
+        quote! {
+            #(#streams)*
+        }
+    }
+
     /// Extract responses that match criteria specified by the `filter`. The
     /// result is a `Vec<OperationResponse>` that enumerates the cases matching
     /// the filter, and a `TokenStream` that represents the generated type for
@@ -1261,12 +1315,18 @@ impl Generator {
 
         // TODO to deal with multiple response types, we'll need to create an
         // enum type with variants for each of the response types.
-        assert!(response_types.len() <= 1);
+        // assert!(response_types.len() <= 1);
-        let response_type = response_types
+        let response_type = if response_types.len() > 1 {
-            .into_iter()
+            OperationResponseKind::Multi(response_types.into_iter().map(Box::new).collect())
-            .next()
+        } else {
-            // TODO should this be OperationResponseType::Raw?
+            response_types
-            .unwrap_or(OperationResponseKind::None);
+                .into_iter()
+                .next()
+                // TODO should this be OperationResponseType::Raw?
+                .unwrap_or(OperationResponseKind::None)
+        };
+
+
         (response_items, response_type)
     }
 

progenitor-impl/src/util.rs

@@ -6,9 +6,13 @@ use indexmap::IndexMap;
 use openapiv3::{
     Components, Parameter, ReferenceOr, RequestBody, Response, Schema,
 };
+use proc_macro2::TokenStream;
+use quote::{format_ident, quote};
+use typify::TypeSpace;
 use unicode_ident::{is_xid_continue, is_xid_start};
 
-use crate::Result;
+use crate::method::OperationResponseKind;
+use crate::{Result};
 
 pub(crate) trait ReferenceOrExt<T: ComponentLookup> {
     fn item<'a>(&'a self, components: &'a Option<Components>) -> Result<&'a T>;
@@ -142,3 +146,116 @@ pub(crate) fn unique_ident_from(
         name.insert_str(0, "_");
     }
 }
+
+/// Generates a unique identifier by concatenating the type identifiers for a collection of `OperationResponseKind`.
+/// This function is used to dynamically create enum variant names or type combinations based on the types contained within a `Multi` response kind.
+pub(crate) fn generate_multi_type_identifier(types: &Vec<Box<OperationResponseKind>>, type_space: &TypeSpace) -> TokenStream {
+    let identifiers: Vec<TokenStream> = types.iter()
+        .map(|type_kind| {
+            match type_kind.as_ref() {
+                OperationResponseKind::None => {
+                    // Directly return a TokenStream representing 'None' if the type is None.
+                    // This case handles the scenario where the generated tokens would have been ().
+                    quote! { None }
+                }
+                OperationResponseKind::Upgrade => {
+                    // Directly return a TokenStream representing 'Upgrade' if the type is Upgrade.
+                    // This case handles the scenario where the generated tokens would have been reqwest::Upgraded.
+                    quote! { Upgraded }
+                }
+                OperationResponseKind::Type(type_id) => {
+                    // Directly use the Ident returned from TypeSpace, ensuring no invalid string manipulation
+                    let type_name = format_ident!("{}", type_space.get_type(type_id).unwrap().ident().to_string().replace("types :: ", ""));
+                    quote! { #type_name }
+                }
+                _ => {
+                    // Otherwise, generate tokens normally using the `into_tokens` method.
+                    type_kind.clone().into_tokens(type_space)
+                }
+            }
+        })
+        .collect();
+
+    // Convert each TokenStream to string, concatenate them with "Or", and prepend with "types::"
+    let concatenated_type = identifiers.iter()
+        .map(|ts| ts.to_string())
+        .collect::<Vec<_>>()
+        .join("Or");
+
+    // Parse the concatenated string back to a TokenStream to ensure that it can be used in code generation.
+    // This step assumes that the concatenated string is a valid Rust identifier or code.
+    let tokens = concatenated_type.parse::<TokenStream>().unwrap_or_else(|_| quote! { InvalidIdentifier });
+    quote! { #tokens } // Return the new identifier as a TokenStream
+}
+pub(crate) fn generate_multi_type_for_types_stream(types: &Vec<Box<OperationResponseKind>>, type_space: &TypeSpace) -> TokenStream {
+    let enum_name = generate_multi_type_identifier(types, type_space);
+
+    // Generate enum variants and their `From` implementations
+    let variants: Vec<TokenStream> = types.iter().map(|type_kind| {
+        match type_kind.as_ref() {
+            OperationResponseKind::None => {
+                quote! { None }
+            }
+            OperationResponseKind::Upgrade => {
+                quote! { Upgraded(reqwest::Upgraded) }
+            }
+            OperationResponseKind::Type(type_id) => {
+                let type_ident = type_space.get_type(type_id).unwrap().ident().to_string().replace("types :: ", "").parse::<TokenStream>().unwrap();
+                quote! { #type_ident(#type_ident) }
+            }
+            _ => quote! { Unknown },
+        }
+    }).collect();
+
+    let from_impls: Vec<TokenStream> = types.iter().map(|type_kind| {
+        match type_kind.as_ref() {
+            OperationResponseKind::None => {
+                quote! {
+                    impl From<()> for #enum_name {
+                        fn from(_: ()) -> Self {
+                            #enum_name::None
+                        }
+                    }
+                }
+            }
+            OperationResponseKind::Upgrade => {
+                quote! {
+                    impl From<reqwest::Upgraded> for #enum_name {
+                        fn from(value: reqwest::Upgraded) -> Self {
+                            #enum_name::Upgraded(value)
+                        }
+                    }
+                }
+            }
+            OperationResponseKind::Type(type_id) => {
+                let type_ident = type_space.get_type(type_id).unwrap().ident().to_string().replace("types :: ", "").parse::<TokenStream>().unwrap();
+                quote! {
+                    impl From<#type_ident> for #enum_name {
+                        fn from(value: #type_ident) -> Self {
+                            #enum_name::#type_ident(value)
+                        }
+                    }
+                }
+            }
+            _ => {
+                todo!() // Possibility of nested Multi types given openapi spec?
+            }
+        }
+    }).collect();
+
+    let tokens = quote! {
+        // Define the enum
+        #[derive(Debug)]
+        pub enum #enum_name {
+            #(#variants),*
+        }
+
+        // Define the From implementations
+        #(#from_impls)*
+    };
+
+    println!("Tokens: {}", tokens);
+
+    tokens
+}
+