Created GitHub Action (#1)

Created GitHub action which gets the PR.

The logic is extremely similar to
[stale-issues-finder](https://github.com/paritytech/stale-issues-finder)
so you will find a lot of duplicated code.

.github/workflows/publish.yml

@@ -1,5 +1,8 @@
 name: Publish package to GitHub Packages
 on:
+  push:
+    branches:
+      - main
   pull_request:
 
 env:

README.md

@@ -1,2 +1,229 @@
-# stale-pr-finder
-Finds stale Pull Requests and return them as an action output
+# Stale Pull Requests Finder
+Finds outdated Pull Requestes and generates an output data & message.
+
+Intended to be used with a notification action (Slack/Discord/Email/etc look at the example usage).
+
+Works great with the [`workflow_dispatch`](https://docs.github.com/en/actions/using-workflows/events-that-trigger-workflows#workflow_dispatch) or [`schedule`](https://docs.github.com/en/actions/using-workflows/events-that-trigger-workflows#schedule) action events.
+
+## Why?
+
+This action is intended for the case where a repository (or an organization) needs to find out what Pull Requests have been stale for a while.
+
+By being agnostic on the result, users can use the output to generate a custom message on their favorite system.
+
+## Example usage
+
+You need to create a file in `.github/workflows` and add the following:
+
+```yml
+name: Find stale PRs
+
+on:
+  workflow_dispatch:
+
+jobs:
+  fetch:
+    permissions:
+        pull-requests: read
+    runs-on: ubuntu-latest
+    steps:
+      - name: Fetch PRs from here
+        # We add the id to access to this step outputs
+        id: stale
+        uses: paritytech/stale-pr-finder@main
+        with:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+          # optional, how many days since the last action for it to be stale
+          # defaults to 5
+          days-stale: 10
+        # example showing how to use the content
+      - name: Produce result
+        run: |
+          echo "There are $AMOUNT stale PRs in this repository"
+          echo "$ACTION_PRS"
+        env:
+          # a number with the amount of stale prs in the repository
+          AMOUNT: ${{ steps.stale.outputs.stale }}"
+          # a formatted markdown message
+          ACTION_PRS: ${{ steps.stale.outputs.message }}"
+```
+
+### Inputs
+You can find all the inputs in [the action file](./action.yml) but let's walk through each one of them:
+
+- `GITHUB_TOKEN`: Token to access to the repository Pull Requests. If you are access a different repository be sure to read the [`accessing other repositories`](#accessing-other-repositories) section.
+  - **required**
+  - If using on the same repo, you can simply use `${{ github.token }}`.
+- `repo`: name of the repository. Example: `https://github.com/paritytech/REPO-NAME-GOES-HERE`
+  - **defaults** to the repo where this action will be run.
+  - Setting this value and `owner` allows you to run this action in other repositories (useful if you want to aggregate all the stale pull requests)
+  - If set, be sure to read the [`accessing other repositories`](#accessing-other-repositories) section.
+- `owner`: name of the organization/user where the repository is. Example: `https://github.com/OWNER-NAME/stale-pr-finder`
+  - **defaults** to the organization where this action is ran.
+- `days-stale`: Amount of days since the last activity for a Pull Request to be considered *stale*.
+  - **default**: 5
+- `noComments`: Boolean. If the action should only fetch Pull Requests that have 0 reviews (comments do not count).
+  - Short for `Ignore PRs that have comments`.
+  - **default**: false
+
+#### Accessing other repositories
+
+The action has the ability to access other repositories but if it can read it or not depends of the repository's visibility.
+
+The default `${{ github.token }}` variable has enough permissions to read the PRs in **public repositories**.
+If you want this action to access to the Pull Requests in a private repository, then you will need a `Personal Access Token` with `repo` permissions.
+
+### Outputs
+Outputs are needed for your chained actions. If you want to use this information, remember to set an `id` field in the step so you can access it.
+You can find all the outputs in [the action file](./action.yml) but let's walk through each one of them:
+- `stale`: Amount of stale PRs found in the step. It's only the number (`0`, `4`, etc)
+- `repo`: Organization and repo name. Written in the format of `owner/repo`.
+- `message`: A markdown message with a list of all the stale PRs. See the example below.
+  - If no stale PRs were found, it will be `## Repo owner/repo has no PRs` instead.
+- `data`: A json object with the data of the stale PRs. See the example below for the format of the data.
+
+**The `message` and `data` objects are sorted from oldest since last change to newest.**
+
+#### Markdown message
+
+An example of how the markdown would be produced for this repository:
+### Repo paritytech/stale-pr-finder has 3 stale PRs
+  - [Stop AI from controlling the world](https://github.com/paritytech/stale-pr-finder/pull/15) - Stale for 25 days
+  - [Lint the repo](https://github.com/paritytech/stale-pr-finder/pull/12) - Stale for 21 days
+  - [Help me with reading](https://github.com/paritytech/stale-pr-finder/pull/3) - Stale for 18 days
+
+You can send the data in this format to a Slack/Discord/Matrix server. You can also create a new GitHub issue with this format.
+
+#### JSON Data
+```json
+[
+    {
+        "url": "https://github.com/paritytech/stale-pr-finder/pull/15",
+        "title": "Stop AI from controlling the world",
+        "number": 15,
+        "daysStale": 25,
+        "reviewCount": 0,
+        "reviews": []
+    },
+    {
+        "url": "https://github.com/paritytech/stale-pr-finder/pull/12",
+        "title": "Lint the repo",
+        "number": 12,
+        "daysStale": 21,
+        "reviewCount": 0,
+        "reviews": []
+    },
+    {
+        "url": "https://github.com/paritytech/stale-pr-finder/pull/3",
+        "title": "Help me with reading",
+        "number": 3,
+        "daysStale": 18,
+        "reviewCount": 0,
+        "reviews": []
+    }
+]
+```
+
+### Using a GitHub app instead of a PAT
+In some cases, specially in big organizations, it is more organized to use a GitHub app to authenticate, as it allows us to give it permissions per repository and we can fine-grain them even better. If you wish to do that, you need to create a GitHub app with the following permissions:
+- Repository permissions:
+	- Pull Requests
+		- [x] Read
+
+Because this project is intended to be used with a token we need to do an extra step to generate one from the GitHub app:
+- After you create the app, copy the *App ID* and the *private key* and set them as secrets.
+- Then you need to modify the workflow file to have an extra step:
+```yml
+    steps:
+      - name: Generate token
+        id: generate_token
+        uses: tibdex/github-app-token@v1
+        with:
+          app_id: ${{ secrets.APP_ID }}
+          private_key: ${{ secrets.PRIVATE_KEY }}
+      - name: Fetch stale PRs from here
+        id: stale
+        uses: paritytech/stale-pr-finder@main
+        with:
+          days-stale: 10
+          # The previous step generates a token which is used as the input for this action
+          GITHUB_TOKEN: ${{ steps.generate_token.outputs.token }}
+```
+
+Be aware that this is needed only to read Pull Requests from **external private repositories**. 
+If the PRs is in the same repository, or the target repository is public, the default `${{ github.token }}` has enough access to read the PRs.
+
+## Example workflow
+
+Let's make an example. We want to have a workflow that runs every Monday at 9 in the morning and it informs through a slack message in a channel. We can also trigger it manually if we want to.
+
+This action needs to run on 3 different repositories:
+- The current repository
+- `example/abc` repository
+- `example/xyz` repository
+
+```yml
+name: Find stale PRs
+
+on:
+  workflow_dispatch:
+  schedule:
+    - cron:  '0 9 * * 1'
+
+jobs:
+  fetch-PRs:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Fetch pull requests from here
+        id: local
+        uses: paritytech/stale-pr-finder@main
+        with:
+          GITHUB_TOKEN: ${{ github.token }}
+      - name: Fetch abc Pull Requests
+        id: abc
+        uses: paritytech/stale-pr-finder@main
+        with:
+          GITHUB_TOKEN: ${{ github.token }}
+          owner: example
+          repo: abc
+      - name: Fetch xyz Pull Requests
+        id: xyz
+        uses: paritytech/stale-pr-finder@main
+        with:
+          GITHUB_TOKEN: ${{ github.token }}
+          owner: example
+          repo: xyz
+      - name: Post to a Slack channel
+        id: slack
+        uses: slackapi/slack-github-action@v1.23.0
+        with:
+          channel-id: 'CHANNEL_ID'
+          slack-message: "Stale PRs this week: \n$LOCAL_PR \n$ABC_PR \n$XYZ_PR"
+        env:
+          SLACK_BOT_TOKEN: ${{ secrets.SLACK_BOT_TOKEN }}
+          LOCAL_PR: ${{ steps.local.outputs.message }}"
+          ABC_PR: ${{ steps.abc.outputs.message }}"
+          XYZ_PR: ${{ steps.xyz.outputs.message }}"
+```
+
+This will produce a message similar to the following:
+
+Stale PRs this week:
+### Repo example/local has 1 stale PRs
+  - [Stop AI from controlling the world](https://github.com/example/local/pull/15) - Stale for 25 days
+### Repo example/abc has 2 stale PRs
+  - [Lint the repo](https://github.com/example/abc/pull/12) - Stale for 21 days
+  - [Help me with reading](https://github.com/example/abc/pull/3) - Stale for 18 days
+### Repo example/xyz has 3 stale PRs
+  - [La la la](https://github.com/example/xyz/pull/15) - Stale for 25 days
+  - [Help with lalilulelo](https://github.comexample/xyz/pull/12) - Stale for 21 days
+  - [Fix the issue with the word 'Patriot'](https://github.com/example/xyz/pull/3) - Stale for 18 days
+
+## Development
+To work on this app, you require
+- `Node 18.x`
+- `yarn`
+
+Use `yarn install` to set up the project.
+
+`yarn build` compiles the TypeScript code to JavaScript.

package.json

@@ -27,6 +27,7 @@
   "dependencies": {
     "@actions/core": "^1.10.0",
     "@actions/github": "^5.1.1",
+    "@eng-automation/integrations": "^4.0.0",
     "moment": "^2.29.4"
   },
   "devDependencies": {

src/filters.ts

@@ -0,0 +1,10 @@
+import moment from "moment";
+import { PullRequest } from "./types";
+
+export const olderThanDays = (pr: PullRequest, daysStale: number): boolean => {
+    return moment().diff(moment(pr.updated_at), "days") > daysStale;
+}
+
+export const byNoReviews = (pr: PullRequest): boolean => {
+    return !pr.reviews || pr.reviews.length === 0;
+}

src/githubApi.ts

@@ -0,0 +1,17 @@
+import { debug } from "@actions/core";
+import { github } from "@eng-automation/integrations";
+import { PullRequest, Repo } from "./types";
+
+export const getPullRequestWithReviews = async (octokitInstance: github.GitHubInstance, repo: Repo): Promise<PullRequest[]> => {
+    const prs = await github.getPullRequests({ state: "open", ...repo }, { octokitInstance });
+    debug(`Found a total of ${prs.length} PRs`);
+
+    const reviews = await Promise.all(prs.map(async (pr) => {
+        debug(`Fetching reviews for PR #${pr.number}`);
+        const { data } = await octokitInstance.rest.pulls.listReviews({ pull_number: pr.number, ...repo });
+        return { ...pr, reviews: data };
+    }))
+
+    const sortedPrs = reviews.sort((a, b) => { return b.updated_at > a.updated_at ? -1 : b.updated_at < a.updated_at ? 1 : 0 });
+    return sortedPrs;
+}