/**
* Tests for diff generation service (Phase 028)
*/
import { describe, it, expect } from 'vitest';
import {
generateDiff,
formatUnifiedDiff,
generateFrontmatterDiff,
formatFrontmatterDiff,
generateChangeSummary,
} from '../../../src/services/history/diff.js';
describe('Diff Service', () => {
describe('generateDiff', () => {
it('should detect no changes for identical content', () => {
const content = 'Line 1\nLine 2\nLine 3';
const result = generateDiff(content, content);
expect(result.hasChanges).toBe(false);
expect(result.additions).toBe(0);
expect(result.deletions).toBe(0);
});
it('should detect additions', () => {
const oldContent = 'Line 1\nLine 2';
const newContent = 'Line 1\nLine 2\nLine 3';
const result = generateDiff(oldContent, newContent);
expect(result.hasChanges).toBe(true);
expect(result.additions).toBe(1);
expect(result.deletions).toBe(0);
});
it('should detect deletions', () => {
const oldContent = 'Line 1\nLine 2\nLine 3';
const newContent = 'Line 1\nLine 2';
const result = generateDiff(oldContent, newContent);
expect(result.hasChanges).toBe(true);
expect(result.additions).toBe(0);
expect(result.deletions).toBe(1);
});
it('should detect modifications', () => {
const oldContent = 'Line 1\nLine 2\nLine 3';
const newContent = 'Line 1\nLine 2 modified\nLine 3';
const result = generateDiff(oldContent, newContent);
expect(result.hasChanges).toBe(true);
expect(result.additions).toBe(1);
expect(result.deletions).toBe(1);
});
it('should handle empty old content', () => {
const oldContent = '';
const newContent = 'Line 1\nLine 2';
const result = generateDiff(oldContent, newContent);
expect(result.hasChanges).toBe(true);
// Empty string splits to [''] which is one "line"
expect(result.additions).toBe(2);
expect(result.deletions).toBe(1); // The empty line
});
it('should handle empty new content', () => {
const oldContent = 'Line 1\nLine 2';
const newContent = '';
const result = generateDiff(oldContent, newContent);
expect(result.hasChanges).toBe(true);
expect(result.additions).toBe(1); // The empty line
expect(result.deletions).toBe(2);
});
});
describe('formatUnifiedDiff', () => {
it('should format diff with header', () => {
const oldContent = 'Line 1\nLine 2';
const newContent = 'Line 1\nLine 2\nLine 3';
const diff = generateDiff(oldContent, newContent);
const formatted = formatUnifiedDiff(diff, 'v1', 'v2');
expect(formatted).toContain('--- v1');
expect(formatted).toContain('+++ v2');
});
it('should show additions with + prefix', () => {
const oldContent = 'Line 1';
const newContent = 'Line 1\nLine 2';
const diff = generateDiff(oldContent, newContent);
const formatted = formatUnifiedDiff(diff);
expect(formatted).toContain('+Line 2');
});
it('should show deletions with - prefix', () => {
const oldContent = 'Line 1\nLine 2';
const newContent = 'Line 1';
const diff = generateDiff(oldContent, newContent);
const formatted = formatUnifiedDiff(diff);
expect(formatted).toContain('-Line 2');
});
it('should return no changes message for identical content', () => {
const content = 'Line 1\nLine 2';
const diff = generateDiff(content, content);
const formatted = formatUnifiedDiff(diff);
expect(formatted).toBe('(no changes)');
});
});
describe('generateFrontmatterDiff', () => {
it('should detect added fields', () => {
const oldContent = '---\ntitle: Test\n---\nContent';
const newContent = '---\ntitle: Test\ntags: [new]\n---\nContent';
const diff = generateFrontmatterDiff(oldContent, newContent);
const addedTags = diff.find(d => d.field === 'tags' && d.type === 'added');
expect(addedTags).toBeDefined();
});
it('should detect removed fields', () => {
const oldContent = '---\ntitle: Test\ntags: [old]\n---\nContent';
const newContent = '---\ntitle: Test\n---\nContent';
const diff = generateFrontmatterDiff(oldContent, newContent);
const removedTags = diff.find(d => d.field === 'tags' && d.type === 'removed');
expect(removedTags).toBeDefined();
});
it('should detect modified fields', () => {
const oldContent = '---\ntitle: Old Title\n---\nContent';
const newContent = '---\ntitle: New Title\n---\nContent';
const diff = generateFrontmatterDiff(oldContent, newContent);
const changedTitle = diff.find(d => d.field === 'title' && d.type === 'changed');
expect(changedTitle).toBeDefined();
expect(changedTitle?.oldValue).toBe('Old Title');
expect(changedTitle?.newValue).toBe('New Title');
});
it('should handle content without frontmatter', () => {
const oldContent = 'Just content';
const newContent = '---\ntitle: New\n---\nContent';
const diff = generateFrontmatterDiff(oldContent, newContent);
const addedTitle = diff.find(d => d.field === 'title' && d.type === 'added');
expect(addedTitle).toBeDefined();
});
});
describe('formatFrontmatterDiff', () => {
it('should format added fields', () => {
const diff = [
{ field: 'tags', oldValue: undefined, newValue: ['test'], type: 'added' as const },
{ field: 'confidence', oldValue: undefined, newValue: 0.9, type: 'added' as const },
];
const formatted = formatFrontmatterDiff(diff);
expect(formatted).toContain('+ tags');
expect(formatted).toContain('+ confidence');
});
it('should format removed fields', () => {
const diff = [
{ field: 'oldField', oldValue: 'value', newValue: undefined, type: 'removed' as const },
];
const formatted = formatFrontmatterDiff(diff);
expect(formatted).toContain('- oldField');
});
it('should format modified fields', () => {
const diff = [{ field: 'title', oldValue: 'Old', newValue: 'New', type: 'changed' as const }];
const formatted = formatFrontmatterDiff(diff);
expect(formatted).toContain('~ title:');
expect(formatted).toContain('"Old"');
expect(formatted).toContain('"New"');
});
it('should return no changes message for empty diff', () => {
const diff: { field: string; oldValue: unknown; newValue: unknown; type: 'added' | 'removed' | 'changed' }[] = [];
const formatted = formatFrontmatterDiff(diff);
expect(formatted).toBe('(no frontmatter changes)');
});
});
describe('generateChangeSummary', () => {
it('should report no changes for identical content', () => {
const content = 'Same content';
const summary = generateChangeSummary(content, content);
expect(summary).toBe('no changes detected');
});
it('should report additions only', () => {
const oldContent = 'Line 1';
const newContent = 'Line 1\nLine 2\nLine 3';
const summary = generateChangeSummary(oldContent, newContent);
expect(summary).toContain('2 additions');
});
it('should report deletions only', () => {
const oldContent = 'Line 1\nLine 2\nLine 3';
const newContent = 'Line 1';
const summary = generateChangeSummary(oldContent, newContent);
expect(summary).toContain('2 deletions');
});
it('should report both additions and deletions', () => {
const oldContent = 'Line 1\nLine 2';
const newContent = 'Line 1\nLine 3\nLine 4';
const summary = generateChangeSummary(oldContent, newContent);
expect(summary).toContain('additions');
expect(summary).toContain('deletions');
});
it('should report single addition', () => {
const oldContent = 'Line 1';
const newContent = 'Line 1\nLine 2';
const summary = generateChangeSummary(oldContent, newContent);
expect(summary).toContain('1 additions');
});
});
});
