add: synth ui unit tests

Author: nithishravindra

packages/cdktf-cli/src/bin/cmds/ui/synth.tsx

@@ -22,14 +22,16 @@ interface SynthConfig extends CommonSynthConfig {
 type SynthOutputConfig = {
   stacks: SynthesizedStack[];
 };
-const SynthOutput = ({ stacks }: SynthOutputConfig): React.ReactElement => {
+export const SynthOutput = ({
+  stacks,
+}: SynthOutputConfig): React.ReactElement => {
   return (
     <Text>
-    {stacks?.length ? (
-        `Generated Terraform code for the stacks: ${stacks.map((s) => s.name).join(", ")}`
-      ) : (
-        "No stacks found in configuration."
-      )}
+      {stacks?.length
+        ? `Generated Terraform code for the stacks: ${stacks
+            .map((s) => s.name)
+            .join(", ")}`
+        : "No stacks found in configuration."}
     </Text>
   );
 };

packages/cdktf-cli/src/test/ui/synth.test.tsx

@@ -0,0 +1,34 @@
+/**
+ * Copyright (c) HashiCorp, Inc.
+ * SPDX-License-Identifier: MPL-2.0
+ */
+
+import React from "react";
+import { render } from "ink-testing-library";
+import { stripAnsi } from "../test-helper";
+import { SynthOutput } from "../../bin/cmds/ui/synth";
+import { SynthesizedStack } from "@cdktf/cli-core";
+
+test("SynthOutput", () => {
+  const { lastFrame } = render(
+    <React.Fragment>
+      <SynthOutput stacks={[]} />
+    </React.Fragment>
+  );
+  expect(stripAnsi(lastFrame())).toBe("No stacks found in configuration.");
+  {
+    const multipleStacks = [
+      { name: "stack1" },
+      { name: "stack2" },
+    ] as SynthesizedStack[];
+
+    const { lastFrame } = render(
+      <React.Fragment>
+        <SynthOutput stacks={multipleStacks} />
+      </React.Fragment>
+    );
+    expect(stripAnsi(lastFrame())).toBe(
+      "Generated Terraform code for the stacks: stack1, stack2"
+    );
+  }
+});