fix(poetry): add ENOENT error handling for missing poetry binary

Throw a clear "poetry is not accessible" error instead of the raw
"spawnSync poetry ENOENT" when the poetry binary is not installed.

Implements TC-4563

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: ruromero

src/providers/python_poetry.js

@@ -47,8 +47,21 @@ export default class Python_poetry extends Base_pyproject {
 	 * @param {Object} opts
 	 * @returns {Promise<{directDeps: string[], graph: Map<string, {name: string, version: string, children: string[]}>}>}
 	 */
+	_verifyPoetryAccessible(poetryBin) {
+		try {
+			invokeCommand(poetryBin, ['--version'])
+		} catch (error) {
+			if (error.code === 'ENOENT') {
+				throw new Error(`poetry is not accessible at "${poetryBin}"`)
+			}
+			throw new Error('failed to check for poetry binary', { cause: error })
+		}
+	}
+
 	// eslint-disable-next-line no-unused-vars
 	async _getDependencyData(manifestDir, _workspaceDir, parsed, opts) {
+		let poetryBin = getCustomPath('poetry', opts)
+		this._verifyPoetryAccessible(poetryBin)
 		let hasDevGroup = !!(parsed.tool?.poetry?.group?.dev || parsed.tool?.poetry?.['dev-dependencies'])
 		let treeOutput = this._getPoetryShowTreeOutput(manifestDir, hasDevGroup, opts)
 		let showAllOutput = this._getPoetryShowAllOutput(manifestDir, opts)

test/providers/python_pyproject.test.js

@@ -2,6 +2,7 @@ import fs from 'fs'
 import path from 'path'
 
 import { expect } from 'chai'
+import esmock from 'esmock'
 import { useFakeTimers } from 'sinon'
 
 import Python_pip_pyproject from '../../src/providers/python_pip_pyproject.js'
@@ -645,3 +646,42 @@ suite('testing the python-pyproject data provider', () => {
 	Object.defineProperty(process, 'platform', { value: originalPlatform, configurable: true })
 	clock.restore()
 })
+
+suite('testing python-poetry error handling', () => {
+	/** Verifies that a missing poetry binary produces a clear error message. */
+	test('verify error when poetry binary is not accessible', async () => {
+		let provider = await esmock('../../src/providers/python_poetry.js', {
+			'../../src/tools.js': {
+				getCustomPath: () => '/nonexistent/poetry',
+				invokeCommand: () => {
+					let err = new Error('spawn /nonexistent/poetry ENOENT')
+					err.code = 'ENOENT'
+					throw err
+				}
+			}
+		})
+
+		let instance = new provider.default()
+		expect(() => instance._verifyPoetryAccessible('/nonexistent/poetry'))
+			.to.throw('poetry is not accessible at "/nonexistent/poetry"')
+	}).timeout(TIMEOUT)
+
+	/** Verifies that non-ENOENT errors are re-thrown with cause chain preserved. */
+	test('verify non-ENOENT errors are re-thrown with cause', async () => {
+		let originalError = new Error('permission denied')
+		originalError.code = 'EACCES'
+
+		let provider = await esmock('../../src/providers/python_poetry.js', {
+			'../../src/tools.js': {
+				getCustomPath: () => 'poetry',
+				invokeCommand: () => {
+					throw originalError
+				}
+			}
+		})
+
+		let instance = new provider.default()
+		expect(() => instance._verifyPoetryAccessible('poetry'))
+			.to.throw('failed to check for poetry binary')
+	}).timeout(TIMEOUT)
+})