feat(ci): Add builds for preview binaries (grain-lang#1777)

* feat(ci): Add builds for preview binaries

* chore(ci): Update actions

* chore(ci): Only run the CI workflow on PR, merge_group, and push-to-main

* document decision

* Remove seemingly unnecessary string quotes

.github/workflows/build-js.yml

@@ -7,19 +7,28 @@ on:
   workflow_dispatch:
     inputs:
       os:
-        description: "Operating system to run CI on"
+        description: Operating system to run CI on
+        type: choice
         required: true
         default: "ubuntu-latest"
-        type: choice
         options:
           - ubuntu-latest
           - macos-latest
           - windows-latest
+      ref:
+        description: Git reference to checkout
+        type: string
+        required: false
   workflow_call:
     inputs:
       os:
+        description: Operating system to run CI on
         type: string
         required: true
+      ref:
+        description: Git reference to checkout
+        type: string
+        required: false
 
 jobs:
   build:
@@ -29,6 +38,8 @@ jobs:
     steps:
       - name: Checkout project
         uses: actions/checkout@v3
+        with:
+          ref: ${{ inputs.ref }}
 
       - name: Setup node.js
         uses: actions/setup-node@v3.6.0

.github/workflows/build-native.yml

@@ -7,19 +7,28 @@ on:
   workflow_dispatch:
     inputs:
       os:
-        description: "Operating system to run CI on"
+        description: Operating system to run CI on
+        type: choice
         required: true
         default: "ubuntu-latest"
-        type: choice
         options:
           - ubuntu-latest
           - macos-latest
           - windows-latest
+      ref:
+        description: Git reference to checkout
+        type: string
+        required: false
   workflow_call:
     inputs:
       os:
+        description: Operating system to run CI on
         type: string
         required: true
+      ref:
+        description: Git reference to checkout
+        type: string
+        required: false
 
 jobs:
   build:
@@ -29,6 +38,8 @@ jobs:
     steps:
       - name: Checkout project
         uses: actions/checkout@v3
+        with:
+          ref: ${{ inputs.ref }}
 
       - name: Setup node.js
         uses: actions/setup-node@v3.6.0

.github/workflows/ci.yml

@@ -1,6 +1,13 @@
 name: Grain CI Workflow
 
-on: [push, pull_request]
+# This is to avoid unnecessary runs.
+# e.g. push AND pull_request against a PR or push against a tag from workflow runs
+# If you need CI to run, you can open a Draft PR to trigger the CI.
+on:
+  push:
+    branches: [main]
+  pull_request:
+  merge_group:
 
 # This will cancel previous runs when a branch or PR is updated
 concurrency:

.github/workflows/generate-docs.yml

@@ -0,0 +1,48 @@
+# This workflow assumes that a `grain-linux-x64` binary was uploaded earlier within the same Action run.
+# It downloads the binary, regenerates the documentation for the project, and pushes it to the ref that was checked out.
+# Note: the `ref` should always be a branch for successful pushes!
+name: Generate documentation
+
+on:
+  workflow_call:
+    inputs:
+      ref:
+        description: Git reference to checkout
+        type: string
+        required: false
+    secrets:
+      PUSH_TOKEN:
+        description: Token used to push back to repository
+        required: true
+
+jobs:
+  generate-docs:
+    name: Generate documentation
+    runs-on: ubuntu-latest
+    steps:
+      - name: Setup bot user
+        run: |
+          git config --global user.email "bot@grain-lang.org"
+          git config --global user.name "Grain Bot"
+
+      - name: Checkout project
+        uses: actions/checkout@v3
+        with:
+          ref: ${{ inputs.ref }}
+          token: ${{ secrets.PUSH_TOKEN }}
+
+      - name: Fetch linux binary
+        uses: actions/download-artifact@v3
+        with:
+          name: grain-linux-x64
+
+      - name: Untar download
+        run: |
+          tar -xvf grain.tar
+
+      - name: Regenerate documentation
+        run: |
+          ./grain doc stdlib -o stdlib --current-version=$(./grain -v)
+          git add stdlib
+          git commit -m 'chore(stdlib): Regenerate markdown documentation'
+          git push