feat: centralize error messages for better maintainability

- Created centralized error-messages.ts file with all error messages organized by category
- Updated all source files to use centralized error messages
- Improved error messages with clearer descriptions and actionable guidance
- Updated tests to match new improved error messages
- All 118 tests passing with 100% coverage

Error messages now include:
- Console logging messages with better context
- API error messages with helpful guidance
- Request handler messages with configuration hints
- Retry policy messages with actionable suggestions

Author: reeshika-h

package-lock.json

@@ -4,3 +4,4 @@ export * from './lib/contentstack-error';
 export * from './lib/api-error';
 export * from './lib/request';
 export * from './lib/retryPolicy/delivery-sdk-handlers';
+export * from './lib/error-messages';

src/index.ts

@@ -1,3 +1,5 @@
+import { ERROR_MESSAGES } from './error-messages';
+
 /**
  * Custom error class for API errors with optimized error handling
  */
@@ -27,10 +29,10 @@ export class APIError extends Error {
       return APIError.fromResponseData(err.response.data, err.response.status);
     } else if (err.message) {
       // For network errors or other non-HTTP errors
-      return new APIError(err.message, err.code || 'NETWORK_ERROR', 0);
+      return new APIError(err.message, err.code || ERROR_MESSAGES.ERROR_CODES.NETWORK_ERROR, 0);
     } else {
       // Fallback for unknown errors
-      return new APIError('Unknown error occurred', 'UNKNOWN_ERROR', 0);
+      return new APIError(ERROR_MESSAGES.API.UNKNOWN_ERROR, ERROR_MESSAGES.ERROR_CODES.UNKNOWN_ERROR, 0);
     }
   }
 
@@ -58,7 +60,7 @@ export class APIError extends Error {
     if (responseData.message) return responseData.message;
     if (responseData.error) return responseData.error;
     if (typeof responseData === 'string') return responseData;
-    return 'Request failed';
+    return ERROR_MESSAGES.API.REQUEST_FAILED();
   }
 
   /**

src/lib/api-error.ts

@@ -2,6 +2,7 @@ import { cloneDeep } from 'lodash';
 import { serialize } from './param-serializer';
 import axios, { AxiosRequestHeaders, getAdapter } from 'axios';
 import { AxiosInstance, HttpClientParams } from './types';
+import { ERROR_MESSAGES } from './error-messages';
 
 export function httpClient(options: HttpClientParams): AxiosInstance {
   const defaultConfig = {
@@ -17,12 +18,12 @@ export function httpClient(options: HttpClientParams): AxiosInstance {
       if (level === 'error') {
         if (data) {
           const title = [data.name, data.message].filter((a) => a).join(' - ');
-          console.error(`[error] ${title}`);
+          console.error(ERROR_MESSAGES.CONSOLE.ERROR_WITH_TITLE(title));
         }
         return;
       }
       if (data !== undefined) {
-        console.log(`[${level}] ${data}`);
+        console.log(ERROR_MESSAGES.CONSOLE.LEVEL_WITH_DATA(level, data));
       }
     },
     retryCondition: (error: any) => {

src/lib/contentstack-core.ts

@@ -0,0 +1,43 @@
+/**
+ * Centralized Error Messages
+ * 
+ * This file contains all error messages used throughout the contentstack-js-core SDK.
+ * Centralizing error messages makes them easier to maintain, review, and localize.
+ */
+
+export const ERROR_MESSAGES = {
+  // Console Logging Messages
+  CONSOLE: {
+    ERROR_WITH_TITLE: (title: string) => `Error: ${title}. Review the error details and try again.`,
+    LEVEL_WITH_DATA: (level: string, data: any) => `${level}: ${data}. Review the details and try again.`,
+  },
+
+  // API Error Messages
+  API: {
+    NETWORK_ERROR: 'Network error occurred. Please check your internet connection and try again.',
+    UNKNOWN_ERROR: 'An unknown error occurred. Please try again or contact support if the issue persists.',
+    REQUEST_FAILED: (status?: number) => 
+      status 
+        ? `Request failed with status ${status}. Please review your request and try again.`
+        : 'Request failed. Please review your request and try again.',
+  },
+
+  // Request Handler Messages
+  REQUEST: {
+    HOST_REQUIRED_FOR_LIVE_PREVIEW: 'Host is required for live preview. Please provide a valid host parameter in the live_preview configuration.',
+  },
+
+  // Retry Policy Messages
+  RETRY: {
+    TIMEOUT_EXCEEDED: (timeout: number) => 
+      `Request timeout of ${timeout}ms exceeded. Please try again or increase the timeout value in your configuration.`,
+  },
+
+  // Error Codes
+  ERROR_CODES: {
+    NETWORK_ERROR: 'NETWORK_ERROR',
+    UNKNOWN_ERROR: 'UNKNOWN_ERROR',
+    TIMEOUT: 408,
+  },
+} as const;
+

src/lib/error-messages.ts

@@ -1,6 +1,7 @@
 import { AxiosInstance } from './types';
 import { serialize } from './param-serializer';
 import { APIError } from './api-error';
+import { ERROR_MESSAGES } from './error-messages';
 
 /**
  * Handles array parameters properly with & separators
@@ -63,7 +64,7 @@ export async function getData(instance: AxiosInstance, url: string, data?: any)
         // adds protocol so host is replaced and not appended
         if (livePreviewParams.live_preview && livePreviewParams.live_preview !== 'init') {
           if (!livePreviewParams.host) {
-            throw new Error('Host is required for live preview');
+            throw new Error(ERROR_MESSAGES.REQUEST.HOST_REQUIRED_FOR_LIVE_PREVIEW);
           }
           url = (livePreviewParams.host.startsWith('https://') ? '' : 'https://') + livePreviewParams.host + url;
         }

src/lib/request.ts

@@ -1,5 +1,6 @@
 /* eslint-disable @typescript-eslint/no-throw-literal */
 import axios, { InternalAxiosRequestConfig, AxiosResponse, AxiosInstance } from 'axios';
+import { ERROR_MESSAGES } from '../error-messages';
 
 declare module 'axios' {
   // eslint-disable-next-line @typescript-eslint/naming-convention
@@ -35,8 +36,8 @@ export const retryResponseErrorHandler = (error: any, config: any, axiosInstance
     if (!response) {
       if (error.code === 'ECONNABORTED') {
         const customError = {
-          error_message: `Timeout of ${config.timeout}ms exceeded`,
-          error_code: 408,
+          error_message: ERROR_MESSAGES.RETRY.TIMEOUT_EXCEEDED(config.timeout),
+          error_code: ERROR_MESSAGES.ERROR_CODES.TIMEOUT,
           errors: null,
         };
         throw customError; // Throw customError object

src/lib/retryPolicy/delivery-sdk-handlers.ts

@@ -74,7 +74,7 @@ describe('APIError', () => {
       const error = APIError.fromAxiosError(axiosError);
 
       expect(error).toBeInstanceOf(APIError);
-      expect(error.error_message).toBe('Unknown error occurred');
+      expect(error.error_message).toBe('An unknown error occurred. Please try again or contact support if the issue persists.');
       expect(error.error_code).toBe('UNKNOWN_ERROR');
       expect(error.status).toBe(0);
     });
@@ -169,7 +169,7 @@ describe('APIError', () => {
       const error = APIError.fromResponseData(responseData, 500);
 
       expect(error).toBeInstanceOf(APIError);
-      expect(error.error_message).toBe('Request failed');
+      expect(error.error_message).toBe('Request failed. Please review your request and try again.');
       expect(error.error_code).toBe(500);
       expect(error.status).toBe(500);
     });

test/api-error.spec.ts

@@ -17,7 +17,7 @@ describe('contentstackCore', () => {
       const consoleErrorSpy = jest.spyOn(console, 'error').mockImplementation();
       httpClient({}).defaults.logHandler('error', error);
 
-      expect(consoleErrorSpy).toHaveBeenCalledWith('[error] Error - Something went wrong');
+      expect(consoleErrorSpy).toHaveBeenCalledWith('Error: Error - Something went wrong. Review the error details and try again.');
 
       consoleErrorSpy.mockRestore();
     });
@@ -36,7 +36,7 @@ describe('contentstackCore', () => {
 
       httpClient({}).defaults.logHandler('info', 'Some message');
 
-      expect(consoleLogSpy).toHaveBeenCalledWith('[info] Some message');
+      expect(consoleLogSpy).toHaveBeenCalledWith('info: Some message. Review the details and try again.');
 
       consoleLogSpy.mockRestore();
     });

test/contentstack-core.spec.ts

@@ -83,7 +83,7 @@ describe('retryResponseErrorHandler', () => {
       expect(err).toEqual(
         expect.objectContaining({
           error_code: 408,
-          error_message: `Timeout of ${config.timeout}ms exceeded`,
+          error_message: `Request timeout of ${config.timeout}ms exceeded. Please try again or increase the timeout value in your configuration.`,
           errors: null,
         })
       );