Show a "What's new?" teaser after installation (once)

src/extension.ts

@@ -2,13 +2,16 @@ import * as vscode from "vscode";
 import { registerShebangCompletionProviders } from "./createShebangCompletionProvider";
 import OutputWindowLogger from "./OutputWindowLogger";
 import { registerHandleSnippetCompletionCommand } from "./handleSnippetCompletionCommand";
+import { showWhatsNewTeaserIfNeeded } from "./whatsNewTeaser";
 
 export function activate(context: vscode.ExtensionContext) {
   const logger = new OutputWindowLogger();
   logger.writeLine("Shebang Snippets extension is active");
 
   context.subscriptions.concat(registerShebangCompletionProviders(context));
   context.subscriptions.push(registerHandleSnippetCompletionCommand(context));
+
+  showWhatsNewTeaserIfNeeded(context);
 }
 
 export function deactivate() {}

src/settings.ts

@@ -18,3 +18,18 @@ export function setLastShebang(
   ];
   extensionContext.globalState.update("lastShebangs", newLastShebangs);
 }
+
+export function getLastExecutedVersion(
+  extensionContext: vscode.ExtensionContext
+) {
+  return extensionContext.globalState.get<string>("lastExecutedVersion");
+}
+
+export function setLastExecutedVersion(
+  extensionContext: vscode.ExtensionContext
+) {
+  extensionContext.globalState.update(
+    "lastExecutedVersion",
+    extensionContext.extension.packageJSON.version ?? ""
+  );
+}

src/whatsNewTeaser.ts

@@ -0,0 +1,38 @@
+import * as vscode from "vscode";
+import { getLastExecutedVersion, setLastExecutedVersion } from "./settings";
+
+export async function showWhatsNewTeaserIfNeeded(
+  extensionContext: vscode.ExtensionContext
+) {
+  const currentVersion = extensionContext.extension.packageJSON.version;
+  if (
+    wasExtensionUpdatedSinceLastStart(extensionContext) &&
+    currentVersion === "1.0.0"
+  ) {
+    const message = "Welcome to Shebang Snippets";
+    const versionInMessage =
+      currentVersion !== undefined ? ` ${currentVersion}` : "";
+    const result = await vscode.window.showInformationMessage(
+      `${message}${versionInMessage}!`,
+      "What's new?"
+    );
+    if (result === "What's new?") {
+      vscode.env.openExternal(
+        vscode.Uri.parse(
+          "https://github.com/Rpinski/vscode-shebang-snippets/blob/master/CHANGELOG.md"
+        )
+      );
+    }
+
+    setLastExecutedVersion(extensionContext);
+  }
+}
+
+function wasExtensionUpdatedSinceLastStart(
+  extensionContext: vscode.ExtensionContext
+) {
+  return (
+    extensionContext.extension.packageJSON.version !==
+    getLastExecutedVersion(extensionContext)
+  );
+}