Fix updating an existing draft release

Don't just return the release without doing anything else, notably this
didn't allow updating an existing draft release body.

This change required refactoring the code to use a new helper
find_existing_release() function, but the only effective change is that
the main release() function doesn't return early any more if a draft
release already exists.

This commit is best viewed ignoring whitespace-only changes and using
git --color-moved option.

src/github.ts

@@ -179,6 +179,50 @@ export const upload = async (
   return json;
 };
 
+const find_existing_release = async (
+  config: Config,
+  releaser: Releaser,
+  tag: string
+): Promise<Release | null> => {
+  const [owner, repo] = config.github_repository.split("/");
+
+  // you can't get a an existing draft by tag
+  // so we must find one in the list of all releases
+  if (config.input_draft) {
+    for await (const response of releaser.allReleases({
+      owner,
+      repo,
+    })) {
+      let release = response.data.find(
+        (release) => release.name === config.input_name
+      );
+      if (release) {
+        return release;
+      }
+    }
+
+    return null;
+  } else {
+    try {
+      let existingRelease = await releaser.getReleaseByTag({
+        owner,
+        repo,
+        tag,
+      });
+      return existingRelease.data;
+    } catch (error) {
+      if (error.status === 404) {
+        return null;
+      } else {
+        console.log(
+          `⚠️ Unexpected error fetching GitHub release for tag ${config.github_ref}: ${error}`
+        );
+        throw error;
+      }
+    }
+  }
+};
+
 export const release = async (
   config: Config,
   releaser: Releaser,
@@ -198,30 +242,9 @@ export const release = async (
 
   const discussion_category_name = config.input_discussion_category_name;
   const generate_release_notes = config.input_generate_release_notes;
-  try {
-    // you can't get a an existing draft by tag
-    // so we must find one in the list of all releases
-    if (config.input_draft) {
-      for await (const response of releaser.allReleases({
-        owner,
-        repo,
-      })) {
-        let release = response.data.find(
-          (release) => release.name === config.input_name
-        );
-        if (release) {
-          return release;
-        }
-      }
-    }
-    let existingRelease = (
-      await releaser.getReleaseByTag({
-        owner,
-        repo,
-        tag,
-      })
-    ).data;
 
+  const existingRelease = await find_existing_release(config, releaser, tag);
+  if (existingRelease !== null) {
     const release_id = existingRelease.id;
     let target_commitish: string;
     if (
@@ -274,51 +297,44 @@ export const release = async (
       generate_release_notes,
     });
     return release.data;
-  } catch (error) {
-    if (error.status === 404) {
-      const tag_name = tag;
-      const name = config.input_name || tag;
-      const body = releaseBody(config);
-      const draft = config.input_draft;
-      const prerelease = config.input_prerelease;
-      const target_commitish = config.input_target_commitish;
-      let commitMessage: string = "";
-      if (target_commitish) {
-        commitMessage = ` using commit "${target_commitish}"`;
-      }
-      console.log(
-        `👩‍🏭 Creating new GitHub release for tag ${tag_name}${commitMessage}...`
-      );
-      try {
-        let release = await releaser.createRelease({
-          owner,
-          repo,
-          tag_name,
-          name,
-          body,
-          draft,
-          prerelease,
-          target_commitish,
-          discussion_category_name,
-          generate_release_notes,
-        });
-        return release.data;
-      } catch (error) {
-        // presume a race with competing metrix runs
-        console.log(
-          `⚠️ GitHub release failed with status: ${
-            error.status
-          }\n${JSON.stringify(error.response.data.errors)}\nretrying... (${
-            maxRetries - 1
-          } retries remaining)`
-        );
-        return release(config, releaser, maxRetries - 1);
-      }
-    } else {
+  } else {
+    const tag_name = tag;
+    const name = config.input_name || tag;
+    const body = releaseBody(config);
+    const draft = config.input_draft;
+    const prerelease = config.input_prerelease;
+    const target_commitish = config.input_target_commitish;
+    let commitMessage: string = "";
+    if (target_commitish) {
+      commitMessage = ` using commit "${target_commitish}"`;
+    }
+    console.log(
+      `👩‍🏭 Creating new GitHub release for tag ${tag_name}${commitMessage}...`
+    );
+    try {
+      let release = await releaser.createRelease({
+        owner,
+        repo,
+        tag_name,
+        name,
+        body,
+        draft,
+        prerelease,
+        target_commitish,
+        discussion_category_name,
+        generate_release_notes,
+      });
+      return release.data;
+    } catch (error) {
+      // presume a race with competing metrix runs
       console.log(
-        `⚠️ Unexpected error fetching GitHub release for tag ${config.github_ref}: ${error}`
+        `⚠️ GitHub release failed with status: ${
+          error.status
+        }\n${JSON.stringify(error.response.data.errors)}\nretrying... (${
+          maxRetries - 1
+        } retries remaining)`
       );
-      throw error;
+      return release(config, releaser, maxRetries - 1);
     }
   }
 };