fix: open feedback form on preuninstall

preuninstall.js

@@ -1,14 +1,11 @@
 "use strict";
 
+var path = require("path");
 var child_process = require("child_process");
-var commandArgs = ["bin/tns", "dev-preuninstall"];
+var commandArgs = [path.join(__dirname, "bin", "tns"), "dev-preuninstall"];
 
-var child = child_process.exec("node " + commandArgs.join(" "), function (error) {
-	if (error) {
-		// Some npm versions (3.0, 3.5.1, 3.7.3) remove the NativeScript node_modules before the preuninstall script is executed and the script can't find them (the preuninstall script is like postinstall script).
-		// The issue is described in the npm repository https://github.com/npm/npm/issues/8806 and it is not fixed in version 3.1.1 as commented in the conversation.
-		console.error("Failed to complete all pre-uninstall steps.");
-	}
-});
+var childProcess = child_process.spawn(process.execPath, commandArgs, { stdio: "inherit"})
 
-child.stdout.pipe(process.stdout);
+childProcess.on("error", (err) => {
+	console.error(`Failed to complete all pre-uninstall steps. Error is ${err.message}`);
+});

test/preuninstall.ts

@@ -0,0 +1,65 @@
+import { assert } from "chai";
+
+// Use require instead of import in order to replace the `spawn` method of child_process
+const childProcess = require("child_process");
+
+import { SpawnOptions, ChildProcess } from "child_process";
+import * as path from "path";
+import { EventEmitter } from "events";
+
+describe("preuninstall.js", () => {
+	let isSpawnCalled = false;
+	let argsPassedToSpawn: string[] = [];
+	let optionsPassedToSpawn: any[];
+	let dataPassedToConsoleError: string[] = [];
+	const originalSpawn = childProcess.spawn;
+	const originalConsoleError = console.error;
+	let eventEmitter = new EventEmitter();
+
+	beforeEach(() => {
+		isSpawnCalled = false;
+		argsPassedToSpawn = [];
+		dataPassedToConsoleError = [];
+		optionsPassedToSpawn = [];
+		eventEmitter = new EventEmitter();
+		childProcess.spawn = (command: string, args?: string[], options?: SpawnOptions): ChildProcess => {
+			isSpawnCalled = true;
+			argsPassedToSpawn = args;
+			optionsPassedToSpawn.push(options);
+			return <any>eventEmitter;
+		};
+
+		console.error = (data: string) => {
+			dataPassedToConsoleError.push(data);
+		};
+	});
+
+	afterEach(() => {
+		childProcess.spawn = originalSpawn;
+		console.error = originalConsoleError;
+	});
+
+	it("calls dev-preuninstall command of CLI and prints with console.error the error in case childProcess emits error event", () => {
+		require(path.join(__dirname, "..", "preuninstall"));
+
+		assert.isTrue(isSpawnCalled, "child_process.spawn must be called from preuninstall.js");
+
+		const expectedPathToCliExecutable = path.join(__dirname, "..", "bin", "tns");
+
+		assert.isTrue(argsPassedToSpawn.indexOf(expectedPathToCliExecutable) !== -1, `The spawned args must contain path to TNS.
+				Expected path is: ${expectedPathToCliExecutable}, current args are: ${argsPassedToSpawn}.`);
+		assert.isTrue(argsPassedToSpawn.indexOf("dev-preuninstall") !== -1, `The spawned args must contain the name of the preuninstall command.
+				Expected path is: ${expectedPathToCliExecutable}, current args are: ${argsPassedToSpawn}.`);
+		assert.deepEqual(optionsPassedToSpawn, [{ stdio: "inherit" }], "The stdio must be inherit as this way CLI's command can determine correctly if terminal is in interactive mode.");
+		assert.deepEqual(dataPassedToConsoleError, []);
+
+		const errMsg = "this is error message";
+		eventEmitter.emit("error", new Error(errMsg));
+		assert.deepEqual(dataPassedToConsoleError, [`Failed to complete all pre-uninstall steps. Error is ${errMsg}`]);
+	});
+
+	it("ensure package.json has correct preuninstall script", () => {
+		const packageJsonData = require("../package.json");
+		assert.equal(packageJsonData.scripts.preuninstall, "node preuninstall.js");
+	});
+});