feat: add tests for validateLocalFile func

Signed-off-by: michalrozekariane <michal.rozek@arianelabs.com>

src/utils/constants/dictionary.ts

@@ -31,6 +31,8 @@ export const dictionary = {
     requiredFieldMissing: 'Required field is missing',
     requiredTypeFieldIsMissing: 'The required "type" field is missing. ',
     requiredAttributeFieldMissing: 'The required "attributes" field is missing. ',
+    filePermissionDenied: 'Permission denied',
+    fileEmptyOrFormattingError: 'Unexpected end of JSON input',
   },
   hederaActions: {
     clientRequired: 'client is required. You need to log in first.',

src/utils/services/Hip412Validator.ts

@@ -86,9 +86,19 @@ export class Hip412Validator {
   };
 
   static validateLocalFile(filePath: string): FileValidationResult {
-    const fileContent = fs.readFileSync(filePath, 'utf8');
-    const object: MetadataObject = JSON.parse(fileContent);
-    return this.validateSingleMetadataObject(object);
+    try {
+      const fileContent = fs.readFileSync(filePath, 'utf8');
+      const object: MetadataObject = JSON.parse(fileContent);
+      return this.validateSingleMetadataObject(object);
+    } catch (error) {
+      return {
+        isValid: false,
+        errors: {
+          general: [errorToMessage(error)],
+          missingAttributes: [],
+        },
+      };
+    }
   }
 
   static validateLocalDirectory(directoryPath: string): DirectoryValidationResult {

test/unit/validateLocalFile.test.ts

@@ -0,0 +1,54 @@
+import fs from 'fs';
+import { Hip412Validator } from '../../src/utils/services/Hip412Validator';
+import { dictionary } from '../../src/utils/constants/dictionary';
+
+jest.mock('fs');
+
+const mockReadFileSync = fs.readFileSync as jest.Mock;
+
+describe('Hip412Validator.validateLocalFile', () => {
+  beforeEach(() => {
+    jest.resetAllMocks();
+  });
+
+  it('should throw errors during file reading without permissions', () => {
+    mockReadFileSync.mockImplementation(() => {
+      throw new Error(dictionary.validation.filePermissionDenied);
+    });
+    const validationResult = Hip412Validator.validateLocalFile('mockPath.json');
+    expect(validationResult.isValid).toBe(false);
+    expect(validationResult.errors.general).toContain(dictionary.validation.filePermissionDenied);
+  });
+
+  it('should handle JSON files with formatting errors', () => {
+    mockReadFileSync.mockImplementation(() => {
+      throw new Error(dictionary.validation.fileEmptyOrFormattingError);
+    });
+    const validationResult = Hip412Validator.validateLocalFile('mockPath.json');
+    expect(validationResult.isValid).toBe(false);
+    expect(validationResult.errors.general).toEqual([
+      dictionary.validation.fileEmptyOrFormattingError,
+    ]);
+  });
+
+  it('should handle empty or non-existent JSON files', () => {
+    mockReadFileSync.mockReturnValue('');
+    const validationResult = Hip412Validator.validateLocalFile('path/to/empty.json');
+    expect(validationResult.isValid).toBe(false);
+    expect(validationResult.errors.general).toEqual([
+      dictionary.validation.fileEmptyOrFormattingError,
+    ]);
+  });
+
+  it('should validate correctly structured JSON file', () => {
+    const validJson = JSON.stringify({
+      name: 'Example NFT',
+      image: 'https://example.com/nft.jpg',
+      type: 'image/jpeg',
+    });
+    mockReadFileSync.mockReturnValue(validJson);
+    const validationResult = Hip412Validator.validateLocalFile('path/to/valid.json');
+    expect(validationResult.isValid).toBe(true);
+    expect(validationResult.errors.general).toHaveLength(0);
+  });
+});