feat: normalize git reference responses

closes #21

src/index.ts

@@ -1,14 +1,19 @@
 // Import for types only, not a production dependency
 import { Octokit } from "@octokit/core";
-import { EndpointOptions } from "@octokit/types";
+import { EndpointOptions, OctokitResponse } from "@octokit/types";
+import { RequestError } from "@octokit/request-error";
 
 import { VERSION } from "./version";
 import { isIssueLabelsUpdateOrReplace } from "./is-issue-labels-update-or-replace";
+import {
+  isGetReference,
+  isListReferences
+} from "./is-get-reference-or-list-references";
 
 export function enterpriseCompatibility(octokit: Octokit) {
   octokit.hook.wrap(
     "request",
-    (request, options: Required<EndpointOptions>) => {
+    async (request, options: Required<EndpointOptions>) => {
       // see https://github.com/octokit/rest.js/blob/15.x/lib/routes.json#L3046-L3068
       if (isIssueLabelsUpdateOrReplace(options)) {
         options.data = options.labels;
@@ -20,6 +25,50 @@ export function enterpriseCompatibility(octokit: Octokit) {
         }
         return request(options);
       }
+
+      const isGetReferenceRequest = isGetReference(options);
+      const isListReferencesRequest = isListReferences(options);
+      if (isGetReferenceRequest || isListReferencesRequest) {
+        options.url = options.url.replace(
+          /\/repos\/([^/]+)\/([^/]+)\/git\/(ref|matching-refs)\/(.*)$/,
+          "/repos/$1/$2/git/refs/$4"
+        );
+        return request(options)
+          .then((response: OctokitResponse<any>) => {
+            if (isGetReferenceRequest) {
+              if (Array.isArray(response.data)) {
+                throw new RequestError(
+                  `More than one reference found at "${options.url}"`,
+                  404,
+                  {
+                    request: options
+                  }
+                );
+              }
+
+              // ✅ received single reference
+              return response;
+            }
+
+            // make sure that
+            if (!Array.isArray(response.data)) {
+              response.data = [response.data];
+            }
+
+            return response;
+          })
+          .catch((error: RequestError) => {
+            if (isListReferencesRequest && error.status === 404) {
+              return {
+                status: 200,
+                headers: error.headers,
+                data: []
+              };
+            }
+
+            throw error;
+          });
+      }
     }
   );
 }

src/is-get-reference-or-list-references.ts

@@ -0,0 +1,20 @@
+import { EndpointOptions } from "@octokit/types";
+
+const REGEX_IS_GET_REFERENCE_PATH = /\/repos\/[^/]+\/[^/]+\/git\/ref\//;
+const REGEX_IS_LIST_REFERENCES_PATH = /\/repos\/[^/]+\/[^/]+\/git\/matching-refs\//;
+
+export function isGetReference({ method, url }: EndpointOptions) {
+  if (!["GET", "HEAD"].includes(method)) {
+    return false;
+  }
+
+  return REGEX_IS_GET_REFERENCE_PATH.test(url);
+}
+
+export function isListReferences({ method, url }: EndpointOptions) {
+  if (!["GET", "HEAD"].includes(method)) {
+    return false;
+  }
+
+  return REGEX_IS_LIST_REFERENCES_PATH.test(url);
+}