feat(github): update PR if there is a draft already

Fixes #627
tagoro9 · Sep 22, 2020 · 3f2eba9 · 3f2eba9
1 parent ca6e923
commit 3f2eba9
Showing 1 changed file with 48 additions and 9 deletions.
diff --git a/src/git/Github.ts b/src/git/Github.ts
@@ -3,6 +3,7 @@ import {
   IssuesListLabelsForRepoResponseData,
   OctokitResponse,
   PullsCreateResponseData,
+  PullsListResponseData,
   PullsRequestReviewersResponseData,
   UsersGetByUsernameResponseData,
 } from '@octokit/types';
@@ -92,8 +93,8 @@ export class Github implements Remote {
   }: PullRequestData): Promise<PullRequest> {
     this.debug(`Creating pull requests with args: %o`, { labels, reviewers, useDefaults });
     this.messenger.emit('Creating pull request');
-    const prExists = await this.doesPullRequestExistForBranch(branchInfo.name);
-    if (prExists) {
+    const prInfo = await this.getPullRequestInfo(branchInfo.name);
+    if (prInfo !== undefined && (!prInfo.draft || isDraft)) {
       throw new Error('A PR already exists for this branch');
     }
     const [ghLabels, ghReviewers] = await Promise.all([
@@ -139,7 +140,10 @@ export class Github implements Remote {
       this.messenger,
     );
 
-    const initialPrContent = this.getPullRequestContentFromTemplate(branchInfo, issues);
+    const initialPrContent =
+      prInfo !== undefined
+        ? `${prInfo.title}\n${prInfo.body}`
+        : this.getPullRequestContentFromTemplate(branchInfo, issues);
     this.messenger.inThread(true);
     await this.pause();
     const prContent = useDefaults
@@ -150,12 +154,19 @@ export class Github implements Remote {
           prefix: 'fotingo-review',
         });
     this.messenger.inThread(false);
-
-    const githubPr = await this.submitPullRequest({
+    const prOptions = {
       content: prContent,
       isDraft,
       pullRequestHead: branchInfo.name,
-    });
+    };
+
+    let githubPr;
+    if (prInfo !== undefined) {
+      githubPr = await this.updatePullRequest(prInfo, prOptions);
+    } else {
+      githubPr = await this.submitPullRequest(prOptions);
+    }
+
     const pullRequest = {
       issues,
       number: githubPr.number,
@@ -283,6 +294,7 @@ export class Github implements Remote {
   /**
    * Submit a pull request for review
    * @param content Content of the pull request
+   * @param isDraft Create a draft pull request
    * @param pullRequestHead Name of the branch to use as head of the pull request
    */
   private async submitPullRequest({
@@ -305,6 +317,31 @@ export class Github implements Remote {
       .then((response) => response.data);
   }
 
+  /**
+   * Update an existing pull request with the passed information
+   * @param pullRequest Current pull request
+   * @param options Update options
+   * @private
+   */
+  private async updatePullRequest(
+    pullRequest: PullsListResponseData[number],
+    { content, isDraft, pullRequestHead }: SubmitPullRequestOptions,
+  ): Promise<PullsCreateResponseData> {
+    const baseBranch = await this.git.findBaseBranch(true);
+    return this.api.pulls
+      .update({
+        base: baseBranch,
+        body: compose<string, string[], string[], string>(join('\n'), tail, split('\n'))(content),
+        draft: isDraft,
+        head: pullRequestHead,
+        owner: this.config.owner,
+        pull_number: pullRequest.number,
+        repo: this.config.repo,
+        title: compose<string, string[], string>(head, split('\n'))(content),
+      })
+      .then((response) => response.data);
+  }
+
   /**
    * Add reviewers to a pull request
    * @param reviewers Reviewers
@@ -365,10 +402,12 @@ export class Github implements Remote {
   }
 
   /**
-   * Check if a PR already exists for the specified branch
+   * Get the pull request information given a branch name
    * @param branchName Branch name
    */
-  private doesPullRequestExistForBranch(branchName: string): Promise<boolean> {
+  private getPullRequestInfo(
+    branchName: string,
+  ): Promise<PullsListResponseData[number] | undefined> {
     // TODO check if this works with forks
     return this.queueCall(
       () =>
@@ -378,7 +417,7 @@ export class Github implements Remote {
             owner: this.config.owner,
             repo: this.config.repo,
           })
-          .then((response) => response.data.length > 0),
+          .then((resonse: OctokitResponse<PullsListResponseData>) => resonse.data[0]),
       'Checking if there is a PR for %s',
       branchName,
     );