add release workflows and changelog

Author: galargh

.github/scripts/changelog.sh

@@ -0,0 +1,23 @@
+#!/bin/bash
+
+file="./CHANGELOG.md"
+regex='^## \[([0-9]+)\.([0-9]+)\.([0-9]+)\] - ([0-9]{4}-[0-9]{2}-[0-9]{2})$'
+
+version=''
+log=()
+
+while read line; do
+    if [[ $line =~ $regex ]]; then
+        if [[ -z "$version" ]]; then
+            major="${BASH_REMATCH[1]}"
+            minor="${BASH_REMATCH[2]}"
+            patch="${BASH_REMATCH[3]}"
+            version="$major.$minor.$patch"
+            date="${BASH_REMATCH[4]}"
+        else
+            break
+        fi
+    elif [[ ! -z "$version" ]]; then
+        log+=("$line")
+    fi
+done <<< "$(cat "$file")"

.github/workflows/pre-release.yml

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+name: Pre Release
+on: 
+  pull_request:
+    paths: [CHANGELOG.md]
+    branches: [master]
+jobs:
+  Post-Comment:
+    name: Post Comment
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - run: |
+          source .github/scripts/changelog.sh
+          git fetch origin --tags
+          if [[ -z "$(git tag -l "v$version")" ]]; then
+            echo "BODY<<EOF" >> $GITHUB_ENV
+            echo "$(IFS=$'\n'; echo "${log[*]}")" >> $GITHUB_ENV
+            echo "EOF" >> $GITHUB_ENV
+            echo "TAG=v$version" >> $GITHUB_ENV
+          fi
+        shell: bash
+      - if: ${{ env.TAG != '' }}
+        uses: marocchino/sticky-pull-request-comment@82e7a0d3c51217201b3fedc4ddde6632e969a477 # v2.1.1
+        with:
+          header: pre-release
+          recreate: true
+          message: |
+            ## ${{ env.TAG }}
+
+            ${{ env.BODY }}

.github/workflows/release.yml

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+name: Release
+on:
+  workflow_dispatch:
+  push:
+    paths: [CHANGELOG.md]
+    branches: [master]
+jobs:
+  Publish:
+    name: Publish
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - run: |
+          source .github/scripts/changelog.sh
+          git fetch origin --tags
+          if [[ -z "$(git tag -l "v$version")" ]]; then
+            git tag "v$major.$minor.$patch"
+            git tag "v$major.$minor" --force
+            git tag "v$major" --force
+            git push --tags --force
+            echo "BODY<<EOF" >> $GITHUB_ENV
+            echo "$(IFS=$'\n'; echo "${log[*]}")" >> $GITHUB_ENV
+            echo "EOF" >> $GITHUB_ENV
+            echo "TAG=v$version" >> $GITHUB_ENV
+          fi
+        shell: bash
+      - if: ${{ env.TAG != '' }}
+        uses: ncipollo/release-action@40bb172bd05f266cf9ba4ff965cb61e9ee5f6d01 # v1.9.0
+        with:
+          body: |
+            ${{ env.BODY }}
+          tag: ${{ env.TAG }}
+          token: ${{ secrets.GITHUB_TOKEN }}

CHANGELOG.md

@@ -0,0 +1,13 @@
+# Changelog
+All notable changes to this project will be documented in this file.
+
+The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
+and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
+
+## [Unreleased]
+### Added
+- release workflows
+- changelog
+
+### Changed
+- the repository from https://github.com/coryschwartz/testground-github-action to https://github.com/testground/testground-github-action