Daily Test Coverage Improver - Comprehensive CSV parsing tests (parseCSV & exportCSVWithFormattingRules)

react/src/helper/csv-util.test.ts

@@ -3,7 +3,13 @@
  Copyright (c) 2015-2026 Lablup Inc. All rights reserved.
  */
 // csv-util.test.ts
-import { downloadCSV, JSONToCSVBody, UTF8_BOM } from './csv-util';
+import {
+  downloadCSV,
+  exportCSVWithFormattingRules,
+  JSONToCSVBody,
+  parseCSV,
+  UTF8_BOM,
+} from './csv-util';
 
 describe('JSONToCSVBody', () => {
   it('should convert JSON data to CSV format without formatting rules', () => {
@@ -185,3 +191,225 @@ describe('downloadCSV', () => {
     expect(capturedBlob?.type).toBe('text/csv;charset=utf-8;');
   });
 });
+
+describe('exportCSVWithFormattingRules', () => {
+  const originalCreateObjectURL = URL.createObjectURL;
+  const originalRevokeObjectURL = URL.revokeObjectURL;
+  let capturedBlob: Blob | undefined;
+  let capturedAnchor: HTMLAnchorElement | undefined;
+
+  beforeEach(() => {
+    capturedBlob = undefined;
+    capturedAnchor = undefined;
+    vi.useFakeTimers();
+    URL.createObjectURL = vi.fn((blob: Blob) => {
+      capturedBlob = blob;
+      return 'blob:mock-url';
+    }) as typeof URL.createObjectURL;
+    URL.revokeObjectURL = vi.fn() as typeof URL.revokeObjectURL;
+
+    const originalCreateElement = document.createElement.bind(document);
+    vi.spyOn(document, 'createElement').mockImplementation(
+      (tagName: string) => {
+        const element = originalCreateElement(tagName);
+        if (tagName === 'a') {
+          capturedAnchor = element as HTMLAnchorElement;
+          vi.spyOn(element as HTMLAnchorElement, 'click').mockImplementation(
+            () => {},
+          );
+        }
+        return element;
+      },
+    );
+  });
+
+  afterEach(() => {
+    vi.runAllTimers();
+    vi.useRealTimers();
+    vi.restoreAllMocks();
+    URL.createObjectURL = originalCreateObjectURL;
+    URL.revokeObjectURL = originalRevokeObjectURL;
+  });
+
+  const decodeKeepingBOM = async (blob: Blob) =>
+    new TextDecoder('utf-8', { ignoreBOM: true }).decode(
+      await blob.arrayBuffer(),
+    );
+
+  it('should export CSV with formatting rules applied', async () => {
+    const data = [
+      { name: 'Alice', score: 95 },
+      { name: 'Bob', score: 87 },
+    ];
+    const format_rules = {
+      score: (value: number) => `${value}%`,
+    };
+
+    exportCSVWithFormattingRules(data, 'scores.csv', format_rules);
+
+    const text = await decodeKeepingBOM(capturedBlob!);
+    expect(text).toContain('"name","score"');
+    expect(text).toContain('"Alice","95%"');
+    expect(text).toContain('"Bob","87%"');
+    expect(capturedAnchor?.download).toBe('scores.csv');
+  });
+
+  it('should export CSV without formatting rules', async () => {
+    const data = [
+      { id: 1, value: 'test' },
+      { id: 2, value: 'data' },
+    ];
+
+    exportCSVWithFormattingRules(data, 'export');
+
+    const text = await decodeKeepingBOM(capturedBlob!);
+    expect(text).toContain('"id","value"');
+    expect(text).toContain('1,"test"');
+    expect(text).toContain('2,"data"');
+    expect(capturedAnchor?.download).toBe('export.csv');
+  });
+
+  it('should include UTF-8 BOM in exported file', async () => {
+    const data = [{ name: '한글', value: 'Korean' }];
+
+    exportCSVWithFormattingRules(data, 'multilingual.csv');
+
+    const text = await decodeKeepingBOM(capturedBlob!);
+    expect(text.startsWith(UTF8_BOM)).toBe(true);
+  });
+});
+
+describe('parseCSV', () => {
+  it('should parse basic CSV with headers', () => {
+    const csv = 'name,age\nJohn,30\nJane,25';
+    const result = parseCSV(csv);
+
+    expect(result).toEqual([
+      { name: 'John', age: '30' },
+      { name: 'Jane', age: '25' },
+    ]);
+  });
+
+  it('should handle UTF-8 BOM at the start', () => {
+    const csv = '\uFEFFname,value\ntest,123';
+    const result = parseCSV(csv);
+
+    expect(result).toEqual([{ name: 'test', value: '123' }]);
+    expect(result[0]).not.toHaveProperty('\uFEFFname');
+  });
+
+  it('should handle quoted fields with commas', () => {
+    const csv = 'name,description\n"Smith, John","A person"';
+    const result = parseCSV(csv);
+
+    expect(result).toEqual([{ name: 'Smith, John', description: 'A person' }]);
+  });
+
+  it('should handle escaped double quotes inside quoted fields', () => {
+    const csv = 'title,quote\n"Book","She said ""Hello"""';
+    const result = parseCSV(csv);
+
+    expect(result).toEqual([{ title: 'Book', quote: 'She said "Hello"' }]);
+  });
+
+  it('should handle line breaks inside quoted fields', () => {
+    const csv = 'name,bio\n"John","Line 1\nLine 2"';
+    const result = parseCSV(csv);
+
+    expect(result).toEqual([{ name: 'John', bio: 'Line 1\nLine 2' }]);
+  });
+
+  it('should handle CRLF line endings', () => {
+    const csv = 'a,b\r\n1,2\r\n3,4';
+    const result = parseCSV(csv);
+
+    expect(result).toEqual([
+      { a: '1', b: '2' },
+      { a: '3', b: '4' },
+    ]);
+  });
+
+  it('should trim whitespace from unquoted values', () => {
+    const csv = 'name , age \n  John  ,  30  ';
+    const result = parseCSV(csv);
+
+    expect(result).toEqual([{ name: 'John', age: '30' }]);
+  });
+
+  it('should skip fully empty lines', () => {
+    const csv = 'name,value\n\n\nJohn,1\n\nJane,2\n\n';
+    const result = parseCSV(csv);
+
+    expect(result).toEqual([
+      { name: 'John', value: '1' },
+      { name: 'Jane', value: '2' },
+    ]);
+  });
+
+  it('should handle file without trailing newline', () => {
+    const csv = 'x,y\n1,2';
+    const result = parseCSV(csv);
+
+    expect(result).toEqual([{ x: '1', y: '2' }]);
+  });
+
+  it('should return empty array for empty input', () => {
+    expect(parseCSV('')).toEqual([]);
+    expect(parseCSV('\n\n')).toEqual([]);
+    expect(parseCSV('   \n   \n   ')).toEqual([]);
+  });
+
+  it('should handle missing values (sparse rows)', () => {
+    const csv = 'a,b,c\n1,2,3\n4,,6';
+    const result = parseCSV(csv);
+
+    expect(result).toEqual([
+      { a: '1', b: '2', c: '3' },
+      { a: '4', b: '', c: '6' },
+    ]);
+  });
+
+  it('should throw error on unterminated quoted field', () => {
+    const csv = 'name,value\n"John,123';
+
+    expect(() => parseCSV(csv)).toThrow('Unterminated quoted field in CSV');
+  });
+
+  it('should handle empty quoted fields', () => {
+    const csv = 'a,b,c\n"",2,""';
+    const result = parseCSV(csv);
+
+    expect(result).toEqual([{ a: '', b: '2', c: '' }]);
+  });
+
+  it('should handle headers with special characters', () => {
+    const csv = 'email@domain,first-name,last_name\ntest@test.com,John,Doe';
+    const result = parseCSV(csv);
+
+    expect(result).toEqual([
+      {
+        'email@domain': 'test@test.com',
+        'first-name': 'John',
+        last_name: 'Doe',
+      },
+    ]);
+  });
+
+  it('should handle complex mixed quoting scenarios', () => {
+    const csv = `name,address,notes
+"John Doe","123 Main St, Apt ""5""","New customer
+Very important"
+Jane,"456 Oak Ave",Regular`;
+
+    const result = parseCSV(csv);
+
+    expect(result).toEqual([
+      {
+        name: 'John Doe',
+        address: '123 Main St, Apt "5"',
+        notes: 'New customer\nVery important',
+      },
+      { name: 'Jane', address: '456 Oak Ave', notes: 'Regular' },
+    ]);
+  });
+});