Razor Compiler Codespaces Support (#33)

* Support Codespaces for Razor Compiler

* Fix target

.devcontainer/Dockerfile

@@ -0,0 +1,5 @@
+# See here for image contents: https://github.com/microsoft/vscode-dev-containers/tree/v0.177.0/containers/dotnet/.devcontainer/base.Dockerfile
+
+# [Choice] .NET version: 6.0, 5.0, 3.1, 2.1
+ARG VARIANT="6.0"
+FROM mcr.microsoft.com/vscode/devcontainers/dotnet

.devcontainer/devcontainer.json

@@ -0,0 +1,42 @@
+// For format details, see https://aka.ms/devcontainer.json. For config options, see the README at:
+// https://github.com/microsoft/vscode-dev-containers/tree/v0.177.0/containers/dotnet
+{
+  "name": "C# (.NET)",
+  "build": {
+    "dockerfile": "Dockerfile",
+    "args": {
+      // The VARIANT here must align with a dotnet container image that
+      // is publicly available on https://mcr.microsoft.com/v2/vscode/devcontainers/dotnet/tags/list.
+      // We'll default to `latest` as the default. Generally, the .NET version that is baked
+      // into the image by default doesn't matter since we end up installing our own
+      // local version and using that by default in the container environment.
+      "VARIANT": "latest",
+      // Options
+      "INSTALL_NODE": "true",
+      "NODE_VERSION": "lts/*"
+    }
+  },
+  // Add the IDs of extensions you want installed when the container is created.
+  "extensions": [
+    "ms-dotnettools.csharp",
+    "EditorConfig.EditorConfig"
+  ],
+  "settings": {
+    // Loading projects on demand is better for larger codebases
+    "omnisharp.enableMsBuildLoadProjectsOnDemand": true,
+    "omnisharp.enableRoslynAnalyzers": true,
+    "omnisharp.enableEditorConfigSupport": true,
+    "omnisharp.enableImportCompletion": true,
+  },
+  // Use 'postCreateCommand' to run commands after the container is created.
+  "onCreateCommand": "bash -i ${containerWorkspaceFolder}/.devcontainer/scripts/container-creation.sh",
+  // Add the locally installed dotnet to the path to ensure that it is activated
+  // This is needed so that things like the C# extension can resolve the correct SDK version
+  "remoteEnv": {
+    "PATH": "${containerWorkspaceFolder}/.dotnet:${containerEnv:PATH}",
+    "DOTNET_MULTILEVEL_LOOKUP": "0",
+    "TARGET": "net6.0",
+  },
+  // Comment out connect as root instead. More info: https://aka.ms/vscode-remote/containers/non-root.
+  "remoteUser": "vscode"
+}

.devcontainer/scripts/container-creation.sh

@@ -0,0 +1,12 @@
+#!/usr/bin/env bash
+
+set -e
+
+# Install SDK and tool dependencies before container starts
+# Also run the full restore on the repo so that go-to definition
+# and other language features will be available in C# files
+./restore.sh
+
+# The container creation script is executed in a new Bash instance
+# so we exit at the end to avoid the creation process lingering.
+exit

.vscode/extensions.json

@@ -0,0 +1,6 @@
+{
+  "recommendations": [
+    "ms-dotnettools.csharp",
+    "EditorConfig.EditorConfig"
+  ]
+}

.vscode/settings.json

@@ -1,4 +1,11 @@
 {
+  "files.trimTrailingWhitespace": true,
+  "files.associations": {
+    "*.*proj": "xml",
+    "*.props": "xml",
+    "*.targets": "xml",
+    "*.tasks": "xml"
+  },
   "markdownlint.config": {
     "MD028": false,
     "MD025": {