Update to Go 1.20 and React with line numbers

.gitattributes

@@ -0,0 +1,7 @@
+playground/go.sum linguist-generated
+playground/internal/cmd/precompile/go.sum linguist-generated
+
+**/*.a.js linguist-generated
+playground/playground.js linguist-generated
+
+playground/internal/imports/zstdlib.go linguist-generated

.github/workflows/ci.yaml

@@ -0,0 +1,63 @@
+name: CI
+
+on:
+  push:
+    branches: [ "*" ]
+  pull_request:
+    branches: [ "*" ]
+
+permissions:
+  contents: read
+  pull-requests: read
+
+concurrency:
+  group: ci-${{ github.ref }}
+  cancel-in-progress: true
+
+env:
+  GO_VERSION: 1.20.14
+  NODE_VERSION: 18
+  GOLANGCI_VERSION: v1.53.3
+  SOURCE_MAP_SUPPORT: true
+  GOPATH: ${{ github.workspace }}/go
+  GOPHERJS_PATH: ${{ github.workspace }}/go/src/github.com/${{ github.repository }}
+
+jobs:
+  lint:
+    name: Lint Checks
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          path: ${{ env.GOPHERJS_PATH }}
+      - uses: actions/setup-go@v5
+        with:
+          go-version: ${{ env.GO_VERSION }}
+      - name: Install golangci-lint
+        uses: golangci/golangci-lint-action@v3
+        with:
+          working-directory: ${{ env.GOPHERJS_PATH }}/playground
+          version: ${{ env.GOLANGCI_VERSION }}
+          only-new-issues: true
+      - name: Check go.mod
+        working-directory: ${{ env.GOPHERJS_PATH }}/playground
+        run: go mod tidy && git diff --exit-code
+
+  go_tests:
+    name: Go Tests
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          path: ${{ env.GOPHERJS_PATH }}
+      - name: Setup Go
+        uses: actions/setup-go@v5
+        with:
+            go-version: ${{ env.GO_VERSION }}
+      - name: Setup Go Environment
+        working-directory: ${{ env.GOPHERJS_PATH }}
+        shell: bash
+        run: echo "GOROOT=$(go env GOROOT)" >> $GITHUB_ENV
+      - name: Run Playground Tests
+        working-directory: ${{ env.GOPHERJS_PATH }}/playground
+        run: go test -v -race ./...

.gitignore

@@ -1 +1,3 @@
 /playground/playground.js.map
+/playground/compile.js.map
+.DS_Store

go.work

@@ -0,0 +1,7 @@
+go 1.20
+
+use (
+	./playground
+	./playground/internal/cmd/compile
+	./playground/internal/cmd/precompile
+)

playground/README.md

@@ -2,23 +2,85 @@
 
 The playground is a place where users can explore GopherJS without needing to install anything, or to share code with others.
 
+- [Building the playgound](#building-the-playgound)
+- [Development](#development)
+- [Upgrading GopherJS release](#upgrading-gopherjs-release)
+- [Adding a new predefined snippet](#adding-a-new-predefined-snippet)
+
+## Building the playgound
+
+To build the entire playground environment,
+run `go generate`.
+
+This assumes that your `go` matches the current version of `go` that `gopherjs` supports.
+If you have a different version of `go` then install the other versions as
+described in [Managing Go installations](https://go.dev/doc/manage-install).
+
+For example, to build for [GopherJS 1.20.0 for Go 1.20.14](https://github.com/gopherjs/gopherjs/releases/tag/v1.20.0)
+run `go1.20.14 generate`.
+
+Generate will:
+
+1. Install your local version of GopherJS compiler
+2. Build the playground
+3. Build the web worker compiler
+4. Create precompiled standard library packages in the `pkg` directory
+
+To manually build the playground:
+
+1. See [GopherJS](https://github.com/gopherjs/gopherjs) documentation about building GopherJS
+2. Build the playgound with `gopherjs build ./playground.go`
+3. Build the web worker compiler with `gopherjs build ./internal/cmd/compile/compile.go`
+4. Create the precompiled standard library packages with `go run ./internal/cmd/precompile`.
+   Use the same `go` as `gopherjs` as described above
+
 ## Development
 
-To update the entire playground environment, just run `go generate github.com/gopherjs/gopherjs.github.io/playground`. It will install your local version of GopherJS compiler, build the playground, make a temporary copy of Go to /tmp/gopherjsplayground_goroot, rebuild and copy the standard library into the `pkg` directory.
+Working on the playground application itself is made easier by using the
+`gopherjs serve` command serve the playground locally.
 
-Working on the playground application itself is made easier by using the `gopherjs serve` command to rebuild and serve the playground every time you refresh the browser.
+Then open <http://localhost:8080?debug=true&local=true>.
 
-```bash
-gopherjs serve
-```
+The `debug` query will enable debugging for react and verbose output.
+
+If running locally or from a fork, trying to access the remote store will
+fail with a a CORS error. Use the `local` query to make the snippet store
+(used when clicking "Share" or loading with a shared url) use local cache only.
+
+There are a few ways to check changes. When working on the playground itself
+it may be simpliest to run `gopherjs build ./playground.go && gopherjs serve`
+after you have made changes so that the changes will be built and served.
 
-Then open <http://localhost:8080/github.com/gopherjs/gopherjs.github.io/playground>.
+When running code in the playground, the JS that is being run can be seen
+by checking the page source files and finding the webworker that is running
+the code. The webworker should have a GUID name, e.g. `fb29b3a9-d5b0-478d-aaf7-85cb60ddbd6d`,
+and the JS compiled for that code will have the same name (usually without `.js`).
 
 ## Upgrading GopherJS release
 
+To upgrade to the newest version, run
+
 ```shell
 VERSION="$(go list -m -versions -f "{{ range .Versions }}{{ println . }}{{ end }}" github.com/gopherjs/gopherjs | tail -n 1)"
 echo "$VERSION"
 go get -v "github.com/gopherjs/gopherjs@$VERSION"
 go mod tidy
 ```
+
+then rebuild the playground with the correct version of `go`.
+
+When committing the update, make sure that `compile.js` at minimum has been
+updated to use the new version of GopherJS so that we can build in that version.
+
+## Adding a new predefined snippet
+
+The snippets are prewritten example programs such as `Hello` and `Donut`.
+To add new snippets:
+
+1. Write the code you would like to add
+2. Test it in the playground and check the console to make sure it does
+   what you expected it to do
+3. Create file in the [snippets folder](./internal/snippets) for that code and change
+   file extension to `.go.txt`
+4. In [`snippets.go`](./internal/snippets/snippets.go) add the new file as
+   an embedded string and add that string to the `predefined` map.

playground/gen.go

@@ -1,5 +1,6 @@
-//go:generate go run ./internal/cmd/precompile
-//go:generate go install github.com/gopherjs/gopherjs
-//go:generate gopherjs build -m .
+//go:generate $GOROOT/bin/go run ./internal/cmd/precompile
+//go:generate $GOROOT/bin/go install github.com/gopherjs/gopherjs
+//go:generate env GOOS=js GOARCH=ecmascript gopherjs build -m ./internal/cmd/compile/.
+//go:generate env GOOS=js GOARCH=ecmascript gopherjs build -m .
 
 package main

playground/go.mod

@@ -1,22 +1,12 @@
 module github.com/gopherjs/gopherjs.github.io/playground
 
-go 1.17
+go 1.20
 
 require (
-	github.com/gopherjs/gopherjs v1.18.0-beta1
-	github.com/neelance/go-angularjs v0.0.0-20170205214111-8c6312cca6e2
-	github.com/sirupsen/logrus v1.8.3
-	golang.org/x/tools v0.1.12
-	honnef.co/go/js/dom v0.0.0-20210725211120-f030747120f2
+	github.com/google/go-cmp v0.5.8
+	github.com/gopherjs/gopherjs v1.20.1
+	golang.org/x/tools v0.16.0
 	honnef.co/go/js/xhr v0.0.0-20150307031022-00e3346113ae
 )
 
-require (
-	github.com/fsnotify/fsnotify v1.5.1 // indirect
-	github.com/neelance/astrewrite v0.0.0-20160511093645-99348263ae86 // indirect
-	github.com/neelance/sourcemap v0.0.0-20200213170602-2833bce08e4c // indirect
-	github.com/shurcooL/httpfs v0.0.0-20190707220628-8d4bc4ba7749 // indirect
-	golang.org/x/sys v0.0.0-20220722155257-8c9f86f7a55f // indirect
-	gopkg.in/yaml.v3 v3.0.1 // indirect
-	honnef.co/go/js/util v0.0.0-20150216223935-96b8dd9d1621 // indirect
-)
+require honnef.co/go/js/util v0.0.0-20150216223935-96b8dd9d1621 // indirect