Add ability to run tests on VS Code Insiders (#1094)

* Add ability to run tests on VS Code Insiders

Add a new docker compose file that lets us run the tests on VS Code
insiders so we can catch issues before they show up for most users in
the mainline VS Code release.

* Use Swift 6.0 instead of main

.vscode-test.js

@@ -28,7 +28,7 @@ module.exports = defineConfig({
         {
             label: "integrationTests",
             files: ["out/test/suite/**/*.test.js"],
-            version: "stable",
+            version: process.env["VSCODE_VERSION"] ?? "stable",
             workspaceFolder: "./assets/test",
             mocha: {
                 ui: "tdd",
@@ -45,7 +45,7 @@ module.exports = defineConfig({
         {
             label: "unitTests",
             files: ["out/test/unit-tests/**/*.test.js"],
-            version: "stable",
+            version: process.env["VSCODE_VERSION"] ?? "stable",
             mocha: {
                 ui: "tdd",
                 color: true,

docker/docker-compose.2004.60.insiders.yaml

@@ -0,0 +1,15 @@
+services:
+
+  runtime-setup:
+    image: vscode-swift:22.04-6.0-insiders
+    build:
+      args:
+        base_image: "swiftlang/swift:nightly-6.0-jammy"
+
+  test:
+    image: vscode-swift:22.04-6.0-insiders
+    environment:
+      - VSCODE_VERSION=insiders
+
+  shell:
+    image: vscode-swift:22.04-6.0-insiders