feat: More ways to specify R path

CHANGELOG.md

@@ -1,5 +1,9 @@
 # Change Log
 
+## [UNRELEASED]
+
+* In Positron, the extension now uses the selected R runtime for Shiny for R apps. In VS Code, the extension also now consults the `r.rpath.mac`, `r.rpath.windows` or `r.rpath.linux` settings to find the R executable, before falling back to system settings. These settings are part of the [R Debugger extension](https://marketplace.visualstudio.com/items?itemName=RDebugger.r-debugger) ([#64](https://github.com/posit-dev/shiny-vscode/pull/64))
+
 ## 1.0.0
 
 The Shiny extension for VS Code now has a new extension ID: `Posit.shiny`! New Shiny users should install the Shiny extension from [the VS Code marketplace](https://marketplace.visualstudio.com/items?itemName=Posit.shiny) or [https://open-vsx.org/extension/posit/shiny](https://open-vsx.org/extension/posit/shiny).

src/extension-api-utils/extensionHost.ts

@@ -0,0 +1,52 @@
+import * as vscode from "vscode";
+
+declare const globalThis: {
+    [key: string]: any;
+};
+
+export interface HostWebviewPanel extends vscode.Disposable {
+    readonly webview: vscode.Webview;
+    readonly visible: boolean;
+    reveal(viewColumn?: vscode.ViewColumn, preserveFocus?: boolean): void;
+    readonly onDidChangeViewState: vscode.Event<any>;
+    readonly onDidDispose: vscode.Event<void>;
+}
+
+type LanguageRuntimeMetadata = Partial<{
+    // https://github.com/posit-dev/positron/blob/39a01b71/src/positron-dts/positron.d.ts#L357
+    /** The path to the runtime. */
+    runtimePath: string;
+
+    /**
+     * The fully qualified name of the runtime displayed to the user; e.g. "R 4.2 (64-bit)".
+     * Should be unique across languages.
+     */
+    runtimeName: string;
+
+    /**
+     * A language specific runtime name displayed to the user; e.g. "4.2 (64-bit)".
+     * Should be unique within a single language.
+     */
+    runtimeShortName: string;
+
+    /** The version of the runtime itself (e.g. kernel or extension version) as a string; e.g. "0.1" */
+    runtimeVersion: string;
+}>;
+
+export function getExtensionHostPreview(): void | ((url: string) => HostWebviewPanel) {
+    const pst = getPositronAPI();
+    if (!pst) { return; }
+    return (url: string) => pst.window.previewUrl(vscode.Uri.parse(url));
+}
+
+export async function getPositronPreferredRuntime(languageId: string): Promise<LanguageRuntimeMetadata | undefined> {
+    const pst = getPositronAPI();
+    if (!pst) { return; }
+    return await pst.runtime.getPreferredRuntime(languageId);
+}
+
+function getPositronAPI(): undefined | any {
+    if (typeof globalThis?.acquirePositronApi !== "function") { return; }
+
+    return globalThis.acquirePositronApi();
+}

src/net-utils.ts

@@ -4,7 +4,7 @@ import { AddressInfo } from "net";
 import * as vscode from "vscode";
 import { getRemoteSafeUrl } from "./extension-api-utils/getRemoteSafeUrl";
 import { retryUntilTimeout } from "./retry-utils";
-import { getExtensionHostPreview } from "./extension-api-utils/extensionHostPreview";
+import { getExtensionHostPreview } from "./extension-api-utils/extensionHost";
 
 /**
  * Tests if a port is open on a host, by trying to connect to it with a TCP

src/run.ts

@@ -10,6 +10,7 @@
 } from "./shell-utils";
 import { getAppPort, getAutoreloadPort } from "./port-settings";
 import * as winreg from "winreg";
+import { getPositronPreferredRuntime } from "./extension-api-utils/extensionHost";
 
 const DEBUG_NAME = "Debug Shiny app";
 
@@ -344,7 +345,56 @@
 }
 
 async function getRBinPath(bin: string): Promise<string> {
-  return getRPathFromEnv(bin) || (await getRPathFromWindowsReg(bin)) || "";
+  return (
+    (await getRPathFromPositron(bin)) ||
+    getRPathFromConfig(bin) ||
+    getRPathFromEnv(bin) ||
+    (await getRPathFromWindowsReg(bin)) ||
+    ""
+  );
+}
+
+async function getRPathFromPositron(bin: string): Promise<string> {
+  const runtimeMetadata = await getPositronPreferredRuntime("r");
+  if (!runtimeMetadata) {
+    return "";
+  }
+
+  console.log(`[shiny] runtimeMetadata: ${JSON.stringify(runtimeMetadata)}`)
+
+  const runtimePath = runtimeMetadata.runtimePath;
+  if (!runtimePath) {
+    return "";
+  }
+
+  const { platform } = process;
+  const fileExt = platform === "win32" ? ".exe" : "";
+  return path_join(path_dirname(runtimePath), bin + fileExt);
+}
+
+function getRPathFromConfig(bin: string): string {
+  const { platform } = process;
+  const fileExt = platform === "win32" ? ".exe" : "";
+  let osType: string;
+
+  switch (platform) {
+    case "win32":
+      osType = "windows";
+      break;
+    case "darwin":
+      osType = "mac";
+      break;
+    default:
+      osType = "linux";
+  }
+
+  const rPath = vscode.workspace
+    .getConfiguration("r.rpath")
+    .get(osType, undefined);
+
+  console.log(`[shiny] rPath: ${rPath}`);
+
+  return rPath ? path_join(path_dirname(rPath), bin + fileExt) : "";
 }
 
 function getRPathFromEnv(bin: string = "R"): string {