feat: secondary quick pick for selecting Swift Version with runSwiftScript command (#1476)

Implement a secondary quick pick for selecting desired Swift Version for Run Swift Script command, and also enabling global settings for it in vscode workspace.

Author: louisunlimited

Diff for: package.json

@@ -324,6 +324,22 @@
             },
             "markdownDescription": "Additional arguments to pass to `swift build` and `swift test`. Keys and values should be provided as individual entries in the list. If you have created a copy of the build task in `tasks.json` then these build arguments will not be propagated to that task."
           },
+          "swift.scriptSwiftLanguageVersion": {
+            "type": "string",
+            "enum": [
+              "6",
+              "5",
+              "Ask Every Run"
+            ],
+            "enumDescriptions": [
+              "Use Swift 6 when running Swift scripts.",
+              "Use Swift 5 when running Swift scripts.",
+              "Prompt to select the Swift version each time a script is run."
+            ],
+            "default": "6",
+            "markdownDescription": "The default Swift version to use when running Swift scripts.",
+            "scope": "machine-overridable"
+          },
           "swift.packageArguments": {
             "type": "array",
             "default": [],

Diff for: src/commands/runSwiftScript.ts

@@ -18,6 +18,7 @@ import * as fs from "fs/promises";
 import { createSwiftTask } from "../tasks/SwiftTaskProvider";
 import { WorkspaceContext } from "../WorkspaceContext";
 import { Version } from "../utilities/version";
+import configuration from "../configuration";
 
 /**
  * Run the active document through the Swift REPL
@@ -40,6 +41,29 @@ export async function runSwiftScript(ctx: WorkspaceContext) {
         return;
     }
 
+    let target: string;
+
+    const defaultVersion = configuration.scriptSwiftLanguageVersion;
+    if (defaultVersion === "Ask Every Run") {
+        const picked = await vscode.window.showQuickPick(
+            [
+                // Potentially add more versions here
+                { value: "5", label: "Swift 5" },
+                { value: "6", label: "Swift 6" },
+            ],
+            {
+                placeHolder: "Select a target Swift version",
+            }
+        );
+
+        if (!picked) {
+            return;
+        }
+        target = picked.value;
+    } else {
+        target = defaultVersion;
+    }
+
     let filename = document.fileName;
     let isTempFile = false;
     if (document.isUntitled) {
@@ -52,9 +76,8 @@ export async function runSwiftScript(ctx: WorkspaceContext) {
         // otherwise save document
         await document.save();
     }
-
     const runTask = createSwiftTask(
-        [filename],
+        ["-swift-version", target, filename],
         `Run ${filename}`,
         {
             scope: vscode.TaskScope.Global,

Diff for: src/configuration.ts

@@ -328,6 +328,11 @@ const configuration = {
             .get<string[]>("buildArguments", [])
             .map(substituteVariablesInString);
     },
+    get scriptSwiftLanguageVersion(): string {
+        return vscode.workspace
+            .getConfiguration("swift")
+            .get<string>("scriptSwiftLanguageVersion", "6");
+    },
     /** swift package arguments */
     get packageArguments(): string[] {
         return vscode.workspace