Detect Swiftly Installation

src/toolchain/swiftly.ts

@@ -148,7 +148,7 @@ export class Swiftly {
         }
     }
 
-    private static isSupported() {
+    public static isSupported() {
         return process.platform === "linux" || process.platform === "darwin";
     }
 
@@ -235,4 +235,16 @@ export class Swiftly {
         );
         return JSON.parse(swiftlyConfigRaw);
     }
+
+    public static async isInstalled(): Promise<boolean> {
+        if (!this.isSupported()) {
+            return false;
+        }
+        try {
+            const { stdout } = await execFile("which", ["swiftly"]);
+            return stdout.trim().length > 0;
+        } catch (error) {
+            return false;
+        }
+    }
 }

src/ui/ToolchainSelection.ts

@@ -259,7 +259,7 @@ async function getQuickPickItems(
     }
     // Various actions that the user can perform (e.g. to install new toolchains)
     const actionItems: ActionItem[] = [];
-    if (process.platform === "linux" || process.platform === "darwin") {
+    if (Swiftly.isSupported() && !(await Swiftly.isInstalled())) {
         const platformName = process.platform === "linux" ? "Linux" : "macOS";
         actionItems.push({
             type: "action",

test/unit-tests/toolchain/swiftly.test.ts

@@ -102,4 +102,48 @@ suite("Swiftly Unit Tests", () => {
             expect(mockUtilities.execFile).not.have.been.called;
         });
     });
+
+    suite("isInstalled", () => {
+        test("should return true when swiftly is found", async () => {
+            mockUtilities.execFile.withArgs("which", ["swiftly"]).resolves({
+                stdout: "/usr/local/bin/swiftly\n",
+                stderr: "",
+            });
+
+            const result = await Swiftly.isInstalled();
+
+            expect(result).to.be.true;
+            expect(mockUtilities.execFile).to.have.been.calledWith("which", ["swiftly"]);
+        });
+
+        test("should return false when swiftly is not found", async () => {
+            mockUtilities.execFile.withArgs("which", ["swiftly"]).rejects(new Error("not found"));
+
+            const result = await Swiftly.isInstalled();
+
+            expect(result).to.be.false;
+            expect(mockUtilities.execFile).to.have.been.calledWith("which", ["swiftly"]);
+        });
+
+        test("should return false when which returns empty output", async () => {
+            mockUtilities.execFile.withArgs("which", ["swiftly"]).resolves({
+                stdout: "",
+                stderr: "",
+            });
+
+            const result = await Swiftly.isInstalled();
+
+            expect(result).to.be.false;
+            expect(mockUtilities.execFile).to.have.been.calledWith("which", ["swiftly"]);
+        });
+
+        test("should return false when platform is not supported", async () => {
+            mockedPlatform.setValue("win32");
+
+            const result = await Swiftly.isInstalled();
+
+            expect(result).to.be.false;
+            expect(mockUtilities.execFile).not.to.have.been.called;
+        });
+    });
 });