Improve error handling and error readability for all commands (#1614)

* fix(cli): improve error handling and error readability for all commands

* chore: bug fix text moved

* fix(cli): consolidate fail() handler message and set exitCode=1 for errors

Agent-Logs-Url: https://github.com/IgniteUI/igniteui-cli/sessions/9e5da6c9-348d-43b7-8bc9-e0b558ebbab3

Co-authored-by: ivanvpetrov <110455887+ivanvpetrov@users.noreply.github.com>

* fix(cli): replace showHelp with getHelp

---------

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: Konstantin Dinev <kdinev@infragistics.com>
Co-authored-by: onlyexeption <ibarakov@infragistics.com>

Author: 4 people

CHANGELOG.md

@@ -84,6 +84,9 @@ A comprehensive modernization of all Angular templates to align with Angular v21
 * **ci:** mark `Util.sanitizeShellArg(x)` as command injection sanitizer for CodeQL ([#1524](https://github.com/IgniteUI/igniteui-cli/pull/1524))
 * **deps:** bump minimatch, ajv, immutable, and lodash ([#1549](https://github.com/IgniteUI/igniteui-cli/pull/1549))
 * **deps:** bump flatted ([#1559](https://github.com/IgniteUI/igniteui-cli/pull/1559))
+* **CLI error handling:** added `.fail()` handler to yargs to gracefully handle command validation errors (e.g., missing required subcommands) instead of showing raw stack traces ([#1614](https://github.com/IgniteUI/igniteui-cli/pull/1614))
+* **Unknown command detection:** running `ig <unknown>` now prints an error message and available commands instead of silently falling through to the step-by-step interactive mode ([#1614](https://github.com/IgniteUI/igniteui-cli/pull/1614))
+* **Unhandled promise rejection:** added `.catch()` in the CLI entry point to catch and display unexpected errors cleanly ([#1614](https://github.com/IgniteUI/igniteui-cli/pull/1614))
 
 ---
 

packages/cli/bin/execute.js

@@ -19,5 +19,8 @@ resolve("igniteui-cli", { basedir: process.cwd() }, function (err, res) {
 	} else {
 		cli = require("../lib/cli");
 	}
-	cli.run(args);
+	cli.run(args).catch(function (err) {
+		console.error("Error: " + (err.message || err));
+		process.exit(1);
+	});
 });

packages/cli/lib/cli.ts

@@ -83,6 +83,14 @@ export async function run(args = null) {
 			false	// setting this to `true` is supposed to exec the middleware after parsing and before arg validation
 					// but in reality it also does not trigger the command's handler (╯°□°）╯︵ ┻━┻
 		)
+		.fail((msg, err, yargs) => {
+			const message = err?.message ?? msg;
+			if (message) {
+				Util.error(message, "red");
+				yargs.showHelp();
+				process.exitCode = 1;
+			}
+		})
 		.help().alias("help", "h")
 		.parseAsync(
 			args, // the args to parse to argv
@@ -121,10 +129,16 @@ export async function run(args = null) {
 				App.testMode = !!argv.testMode;
 
 				if (!helpRequest && !ALL_COMMANDS.has(command?.toString())) {
-					Util.log("Starting Step by step mode.", "green");
-					Util.log("For available commands, stop this execution and use --help.", "green");
-					const prompts = new PromptSession(templateManager);
-					prompts.start();
+					if (command) {
+						process.exitCode = 1;
+						Util.error(`Unknown command: "${command}"`, "red");
+						Util.log(await yargsModule.getHelp());
+					} else {
+						Util.log("Starting Step by step mode.", "green");
+						Util.log("For available commands, stop this execution and use --help.", "green");
+						const prompts = new PromptSession(templateManager);
+						prompts.start();
+					}
 				}
 			}
 		);

spec/unit/cli-spec.ts

@@ -54,15 +54,33 @@ describe("Unit - Cli.ts", () => {
 		await run.run("list");
 		expect(list.handler).toHaveBeenCalled();
 	});
-	it("Should fire properly - fallback to default", async () => {
+	it("Should fire properly - fallback to default with no args", async () => {
 		spyOn(Util , "log");
 		spyOn(GoogleAnalytics, "post");
 		spyOn(PromptSession.prototype, "start");
-		await run.run("Nonexistent command");
+		await run.run([]);
 
 		// expected console output:
 		expect(Util.log).toHaveBeenCalledWith("Starting Step by step mode.", "green");
 		expect(Util.log).toHaveBeenCalledWith("For available commands, stop this execution and use --help.", "green");
 		expect(PromptSession.prototype.start).toHaveBeenCalled();
 	});
+	it("Should show error for unknown command", async () => {
+		spyOn(Util , "log");
+		spyOn(Util , "error");
+		spyOn(GoogleAnalytics, "post");
+		spyOn(PromptSession.prototype, "start");
+		await run.run("nonexistent");
+
+		expect(Util.error).toHaveBeenCalledWith(`Unknown command: "nonexistent"`, "red");
+		expect(PromptSession.prototype.start).not.toHaveBeenCalled();
+	});
+	it("Should gracefully handle subcommand validation errors", async () => {
+		spyOn(Util , "log");
+		spyOn(Util , "error");
+		spyOn(GoogleAnalytics, "post");
+		await run.run("generate");
+
+		expect(Util.error).toHaveBeenCalledWith("Please select command", "red");
+	});
 });