test(resume-parser): add comprehensive test coverage for resume parsing and fallback scenarios (JhaSourav07#3116)

## Description

Adds a dedicated test suite for lib/resume-parser.ts to validate resume
parsing behavior across normal, malformed, and incomplete inputs.

## Changes

- Added lib/resume-parser.test.ts
- Added tests for:
- Well-formatted resume parsing
- Email and phone extraction
- Education section extraction
- Experience section extraction
- Empty/malformed resume handling
- Missing section fallback behavior
- Exported parser constants validation

Fixes JhaSourav07#2290 

## Pillar

- [x] 📐 Pillar 2 — Geometric SVG Improvement
- [x] 🛠️ Other (Bug fix, refactoring, docs)


## Checklist before requesting a review:

- [x] I have read the `CONTRIBUTING.md` file.
- [x] I have tested these changes locally
(`localhost:3000/api/streak?user=YOUR_USERNAME`).
- [x] I have run `npm run format` and `npm run lint` locally and
resolved all errors (CI will fail otherwise).
- [x] My commits follow the Conventional Commits format (e.g.,
`feat(themes): ...`, `fix(calculate): ...`).
- [x] I have updated `README.md` if I added a new theme or URL
parameter.
- [x] I have started the repo.
- [x] I have made sure that i have only one commit to merge in this PR.
- [x] The SVG output matches the CommitPulse "premium quality" aesthetic
standard (no raw elements, smooth animations, correct fonts).
- [x] (Recommended) I joined the CommitPulse Discord community for
contributor discussions, mentorship, and faster PR support.

Author: JhaSourav07

lib/resume-parser.test.ts

@@ -0,0 +1,114 @@
+import { describe, it, expect } from 'vitest';
+import { parseResume, ALLOWED_MIME_TYPES, MAX_FILE_SIZE } from './resume-parser';
+
+describe('resume-parser', () => {
+  it('parses a well formatted resume', async () => {
+    const resume = `
+John Doe
+john.doe@example.com
++1 234-567-8901
+
+Skills
+TypeScript, React, Node.js
+
+Education
+B.Tech Computer Science 2020-2024
+
+Experience
+Software Engineer at ABC Corp 2022-2024
+`;
+
+    const result = await parseResume(Buffer.from(resume), 'application/pdf');
+
+    expect(result.name).toBe('John Doe');
+    expect(result.email).toBe('john.doe@example.com');
+    expect(result.phone).toContain('234');
+    expect(result.skills).toContain('TypeScript');
+    expect(result.education).toHaveLength(1);
+    expect(result.experience).toHaveLength(1);
+  });
+
+  it('extracts contact information correctly', async () => {
+    const resume = `
+Jane Smith
+jane.smith@gmail.com
+(555) 123-4567
+`;
+
+    const result = await parseResume(Buffer.from(resume), 'application/pdf');
+
+    expect(result.email).toBe('jane.smith@gmail.com');
+    expect(result.phone).toContain('555');
+  });
+
+  it('extracts education and experience sections', async () => {
+    const resume = `
+Robert Brown
+
+Education
+University of Testing 2018-2022
+
+Experience
+Frontend Developer at XYZ 2022-2024
+`;
+
+    const result = await parseResume(Buffer.from(resume), 'application/pdf');
+
+    expect(result.education).toEqual([
+      expect.objectContaining({
+        institution: 'University of Testing 2018-2022',
+        startDate: '2018',
+        endDate: '2022',
+      }),
+    ]);
+
+    expect(result.experience).toEqual([
+      expect.objectContaining({
+        company: 'Frontend Developer at XYZ 2022-2024',
+        startDate: '2022',
+        endDate: '2024',
+      }),
+    ]);
+  });
+
+  it('handles empty or malformed resume text', async () => {
+    const result = await parseResume(Buffer.from(''), 'application/pdf');
+
+    expect(result).toEqual({
+      name: '',
+      email: '',
+      phone: '',
+      skills: [],
+      education: [],
+      experience: [],
+    });
+  });
+
+  it('returns sensible fallbacks when sections are missing', async () => {
+    const resume = `
+Alex Johnson
+alex@example.com
+
+Random text without any section headers.
+`;
+
+    const result = await parseResume(Buffer.from(resume), 'application/pdf');
+
+    expect(result.name).toBe('Alex Johnson');
+    expect(result.email).toBe('alex@example.com');
+    expect(result.skills).toEqual([]);
+    expect(result.education).toEqual([]);
+    expect(result.experience).toEqual([]);
+  });
+});
+
+describe('parser constants', () => {
+  it('exports allowed mime types and max file size', () => {
+    expect(ALLOWED_MIME_TYPES).toContain('application/pdf');
+    expect(ALLOWED_MIME_TYPES).toContain(
+      'application/vnd.openxmlformats-officedocument.wordprocessingml.document'
+    );
+
+    expect(MAX_FILE_SIZE).toBe(5 * 1024 * 1024);
+  });
+});