Allow unstable branches to be merged (#25)

Added the ability to merge [unstable
branches](https://docs.github.com/en/graphql/reference/enums#mergestatestatus).

This is enabled by default, as GitHub's Auto Merge feature always merges
unstable branches.

Fixes #24

README.md

@@ -31,6 +31,7 @@ jobs:
         with:
           GITHUB_TOKEN: '${{ github.token }}'
           MERGE_METHOD: "SQUASH"
+          ALLOW_UNSTABLE: true
 ```
 
 #### Inputs
@@ -48,6 +49,10 @@ You can find all the inputs in [the action file](./action.yml), but let's walk t
 - `ALLOWLIST`: List of user accounts which are allowed to use the bot aside from the author and org members.
 	- **Optional**
 	- Must be a comma separated value: `user-1,user-2,user-3`.
+- `ALLOW_UNSTABLE`: If unstable, ready to merge, PRs can be merged
+  - An [unstable PR](https://docs.github.com/en/graphql/reference/enums#mergestatestatus) is a PR that can be merged, but a *non required status check* is failing.
+    - This is only relevant once the PR can be merged. GitHub's auto-merge always merges unstable PRs
+  - **Optional**: Defaults to `true`
 
 ## Usage
 

action.yml

@@ -18,10 +18,13 @@ inputs:
   ALLOWLIST:
     required: false
     description: List of users which are allowed to use the bot. Separated by commas (abc,def,ghi)
+  ALLOW_UNSTABLE:
+    required: false
+    description: If unstable, ready to merge, PRs can be merged. Defaults to true
 outputs:
   repo:
     description: 'The name of the repo in owner/repo pattern'
 
 runs:
   using: 'docker'
-  image: 'docker://ghcr.io/paritytech/auto-merge-bot/action:1.0.0'
+  image: 'docker://ghcr.io/paritytech/auto-merge-bot/action:1.0.1'

package.json

@@ -1,6 +1,6 @@
 {
   "name": "auto-merge-bot",
-  "version": "1.0.0",
+  "version": "1.0.1",
   "description": "Bot which enables or disable auto-merge",
   "main": "src/index.ts",
   "scripts": {

src/github/merger.ts

@@ -35,8 +35,26 @@ export class Merger {
     private readonly gql: typeof graphql,
     private readonly logger: ActionLogger,
     private readonly mergeMethod: PullRequestMergeMethod,
+    private readonly allowUnstable: boolean = false,
   ) {}
 
+  errorPermitsToMerge(error: Error): boolean {
+    // If it's clean it can be merged
+    if (error.message.includes("Pull request is in clean status")) {
+      return true;
+    }
+
+    // If it is unstable and allowed, it can also be merged
+    if (error.message.includes("Pull request is in unstable status")) {
+      this.logger.warn(
+        "PR is unstable! Some non required status checks are failing.",
+      );
+      return this.allowUnstable;
+    }
+
+    return false;
+  }
+
   async enableAutoMerge(): Promise<void> {
     try {
       await this.gql<{
@@ -48,10 +66,7 @@ export class Merger {
       this.logger.info("Succesfully enabled auto-merge");
     } catch (error) {
       this.logger.warn(error as Error);
-      if (
-        error instanceof Error &&
-        error.message.includes("Pull request is in clean status")
-      ) {
+      if (error instanceof Error && this.errorPermitsToMerge(error)) {
         this.logger.warn(
           "Pull Request is ready to merge. Running merge command instead",
         );

src/index.ts

@@ -52,6 +52,11 @@ const getMergeMethod = (): PullRequestMergeMethod => {
   return method;
 };
 
+/** If it should allow PRs that have failed NON REQUIRED status check to be merged */
+const getAllowUnstable = (): boolean => {
+  return getInput("ALLOW_UNSTABLE", { required: false }) !== "false";
+};
+
 const silentMode = getInput("SILENT", { required: false }) === "true";
 
 logger.info(
@@ -80,7 +85,15 @@ if (context.payload.comment) {
   const gql = getOctokit(token).graphql.defaults({
     headers: { authorization: `token ${token}` },
   }) as graphql;
-  const merger = new Merger(issue.node_id, gql, logger, getMergeMethod());
+  const mergeMethod = getMergeMethod();
+  const unstableAllowed = getAllowUnstable();
+  const merger = new Merger(
+    issue.node_id,
+    gql,
+    logger,
+    mergeMethod,
+    unstableAllowed,
+  );
   const bot = new Bot(
     comment,
     issue,