feat: enhance configuration quality to match EnvSync-LE/String-LE standards

- Add validation functions and type guards (isValidNotificationLevel, isValidOutputFormat, isValidTimezone)
- Add sophisticated error handling with categorization and recovery options
- Improve configuration structure with proper validation and fallbacks
- Add backward compatibility for legacy settings (notificationsLevel vs notificationLevel)
- Enhance performance settings with proper bounds checking
- Add comprehensive error handling utilities with user-friendly messages

Author: nolindnaidoo

src/config/config.ts

@@ -4,30 +4,62 @@ import type { Configuration } from '../types'
 export function getConfiguration(): Configuration {
 	const config = vscode.workspace.getConfiguration('dates-le')
 
+	// Backward-compat: support both `notificationLevel` (preferred) and legacy `notificationsLevel`
+	const notifRaw = config.get('notificationLevel', config.get('notificationsLevel', 'silent')) as unknown as string
+	const notificationsLevel = isValidNotificationLevel(notifRaw) ? notifRaw : 'silent'
+	
+	const outputFormatRaw = config.get('outputFormat', 'iso')
+	const outputFormat = isValidOutputFormat(outputFormatRaw) ? outputFormatRaw : 'iso'
+	
+	const timezoneRaw = config.get('timezone', 'UTC')
+	const timezone = isValidTimezone(timezoneRaw) ? timezoneRaw : 'UTC'
+
 	return Object.freeze({
-		copyToClipboardEnabled: config.get<boolean>('copyToClipboardEnabled', false),
-		dedupeEnabled: config.get<boolean>('dedupeEnabled', false),
-		notificationsLevel: config.get<'all' | 'important' | 'silent'>('notificationsLevel', 'silent'),
-		postProcessOpenInNewFile: config.get<boolean>('postProcess.openInNewFile', false),
-		openResultsSideBySide: config.get<boolean>('openResultsSideBySide', false),
-		safetyEnabled: config.get<boolean>('safety.enabled', true),
-		safetyFileSizeWarnBytes: config.get<number>('safety.fileSizeWarnBytes', 1000000),
-		safetyLargeOutputLinesThreshold: config.get<number>('safety.largeOutputLinesThreshold', 50000),
-		safetyManyDocumentsThreshold: config.get<number>('safety.manyDocumentsThreshold', 8),
-		showParseErrors: config.get<boolean>('showParseErrors', false),
-		statusBarEnabled: config.get<boolean>('statusBar.enabled', true),
-		telemetryEnabled: config.get<boolean>('telemetryEnabled', false),
-		analysisEnabled: config.get<boolean>('analysis.enabled', true),
-		analysisIncludePatterns: config.get<boolean>('analysis.includePatterns', true),
-		analysisIncludeRanges: config.get<boolean>('analysis.includeRanges', true),
-		analysisIncludeAnomalies: config.get<boolean>('analysis.includeAnomalies', true),
-		outputFormat: config.get<'iso' | 'rfc2822' | 'unix' | 'utc' | 'local' | 'original'>('outputFormat', 'iso'),
-		timezone: config.get<string>('timezone', 'UTC'),
-		performanceEnabled: config.get<boolean>('performance.enabled', true),
-		performanceMaxDuration: config.get<number>('performance.maxDuration', 5000),
-		performanceMaxMemoryUsage: config.get<number>('performance.maxMemoryUsage', 104857600),
-		performanceMaxCpuUsage: config.get<number>('performance.maxCpuUsage', 1000000),
-		performanceMinThroughput: config.get<number>('performance.minThroughput', 1000),
-		performanceMaxCacheSize: config.get<number>('performance.maxCacheSize', 1000),
+		copyToClipboardEnabled: Boolean(config.get('copyToClipboardEnabled', false)),
+		dedupeEnabled: Boolean(config.get('dedupeEnabled', false)),
+		notificationsLevel,
+		postProcessOpenInNewFile: Boolean(config.get('postProcess.openInNewFile', false)),
+		openResultsSideBySide: Boolean(config.get('openResultsSideBySide', false)),
+		safetyEnabled: Boolean(config.get('safety.enabled', true)),
+		safetyFileSizeWarnBytes: Math.max(1000, Number(config.get('safety.fileSizeWarnBytes', 1000000))),
+		safetyLargeOutputLinesThreshold: Math.max(100, Number(config.get('safety.largeOutputLinesThreshold', 50000))),
+		safetyManyDocumentsThreshold: Math.max(1, Number(config.get('safety.manyDocumentsThreshold', 8))),
+		showParseErrors: Boolean(config.get('showParseErrors', false)),
+		statusBarEnabled: Boolean(config.get('statusBar.enabled', true)),
+		telemetryEnabled: Boolean(config.get('telemetryEnabled', false)),
+		analysisEnabled: Boolean(config.get('analysis.enabled', true)),
+		analysisIncludePatterns: Boolean(config.get('analysis.includePatterns', true)),
+		analysisIncludeRanges: Boolean(config.get('analysis.includeRanges', true)),
+		analysisIncludeAnomalies: Boolean(config.get('analysis.includeAnomalies', true)),
+		outputFormat,
+		timezone,
+		performanceEnabled: Boolean(config.get('performance.enabled', true)),
+		performanceMaxDuration: Math.max(1000, Number(config.get('performance.maxDuration', 5000))),
+		performanceMaxMemoryUsage: Math.max(1048576, Number(config.get('performance.maxMemoryUsage', 104857600))),
+		performanceMaxCpuUsage: Math.max(100000, Number(config.get('performance.maxCpuUsage', 1000000))),
+		performanceMinThroughput: Math.max(100, Number(config.get('performance.minThroughput', 1000))),
+		performanceMaxCacheSize: Math.max(100, Number(config.get('performance.maxCacheSize', 1000))),
 	})
 }
+
+export type NotificationLevel = 'all' | 'important' | 'silent'
+export type OutputFormat = 'iso' | 'rfc2822' | 'unix' | 'utc' | 'local' | 'original'
+
+export function isValidNotificationLevel(v: unknown): v is NotificationLevel {
+	return v === 'all' || v === 'important' || v === 'silent'
+}
+
+export function isValidOutputFormat(v: unknown): v is OutputFormat {
+	return (
+		v === 'iso' ||
+		v === 'rfc2822' ||
+		v === 'unix' ||
+		v === 'utc' ||
+		v === 'local' ||
+		v === 'original'
+	)
+}
+
+export function isValidTimezone(v: unknown): v is string {
+	return typeof v === 'string' && v.length > 0 && v.length <= 50
+}