feat: initial implementation

Author: satya164

.gitignore

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+.history/

README.md

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+# Check versions action
+
+This action checks for missing or outdated versions of packages mentioned in the issue.
+
+## How it works
+
+The action will check the issue content for name of packages and try to extract the version numbers. If some of the packages are missing version numbers or don't match the latest version numbers on npm, then it'll comment on the issue.
+
+![demo](assets/screenshot.png)
+
+## Installation
+
+Create a new workflow file (e.g. `.github/workflows/check-versions.yml`) and add the following configuration:
+
+```yml
+name: Check versions
+on:
+  issues:
+    types: [opened]
+
+jobs:
+  check-versions:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: react-navigation/check-versions-action@master
+        with:
+          github-token: ${{ secrets.GITHUB_TOKEN }}
+          packages: |
+            @react-navigation/native
+            @react-navigation/stack
+          missing-versions-label: 'needs more info'
+```
+
+Make sure to change the `packages` list and the `missing-versions-label`.
+
+## Inputs
+
+### `github-token` (`required`)
+
+The `GITHUB_TOKEN` secret. This is needed so that we can post comments on the issue.
+
+### `packages` (`required`)
+
+List of packages to check for. The action will match the content of the issue against these package names to find mentioned versions. If there are packages present in the issue, but not mentioned in this list, then they will be ignored.
+
+### `comment`
+
+Boolean to indicate whether the action should comment on the issue on finding missing or outdated versions. Defaults to `true`.
+
+Set it to `false` if you want to use the action as a filter.
+
+### `missing-versions-label`
+
+Label to add when missing or outdated versions are found.
+
+## Outputs
+
+### `found`
+
+Packages and version numbers found. It'll be formatted like `@react-navigation/stack@5.1.2,@react-navigation/native@5.0.5`.
+
+### `outdated`
+
+Packages with outdated versions and their latest versions. It'll be formatted like `@react-navigation/stack@5.1.2,@react-navigation/native@5.0.5`.
+
+### `missing`
+
+Packages missing version numbers. It'll be formatted like `@react-navigation/stack,@react-navigation/native`.

action.yml

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+name: 'Check versions'
+description: 'Check for missing or outdated versions of packages mentioned in the issue'
+author: 'Satyajit Sahoo'
+
+branding:
+  icon: 'alert-triangle'
+  color: 'orange'
+
+inputs:
+  github-token:
+    description: The `GITHUB_TOKEN` secret.
+    required: true
+  packages:
+    description: 'List of packages to check for'
+    required: true
+  comment:
+    description: 'Whether to comment on the issue when missing or outdated versions are found'
+    default: true
+  missing-versions-label:
+    description: 'Label to add when missing or outdated versions are found'
+
+outputs:
+  found:
+    description: 'Packages and version numbers found'
+  outdated:
+    description: 'Packages with outdated versions and their latest versions'
+  missing:
+    description: 'Packages missing version numbers'
+
+runs:
+  using: 'node12'
+  main: 'src/index.js'