apisurf/lib/utilities/formatOutput.test.js

Analyze API surface changes between npm package versions to catch breaking changes

import { describe, it, expect } from '@jest/globals';
import { formatOutput } from './formatOutput.js';
describe('formatOutput', () => {
    it('returns success message when no breaking changes', () => {
        const result = {
            hasBreakingChanges: false,
            packages: [],
            summary: 'No breaking changes detected',
            semverImpact: { minimumBump: 'patch', reason: 'No changes detected' }
        };
        const output = formatOutput(result, 'console', false);
        expect(output).toMatch(/✅ No changes detected/);
    });
    it('returns JSON when format is json', () => {
        const result = {
            hasBreakingChanges: false,
            packages: [],
            summary: 'No breaking changes detected',
            semverImpact: { minimumBump: 'patch', reason: 'No changes detected' }
        };
        const output = formatOutput(result, 'json', false);
        const parsed = JSON.parse(output);
        expect(parsed.hasBreakingChanges).toBe(false);
        expect(parsed.summary).toBe('No breaking changes detected');
    });
    it('returns markdown format when requested', () => {
        const result = {
            hasBreakingChanges: false,
            packages: [],
            summary: 'No changes',
            semverImpact: { minimumBump: 'patch', reason: 'No changes detected' }
        };
        const output = formatOutput(result, 'md', false);
        expect(output).toMatch(/## API Surface Analysis/);
        expect(output).toMatch(/✅ No changes detected/);
    });
    it('console output has proper blank line spacing', () => {
        const result = {
            hasBreakingChanges: true,
            packages: [{
                    name: '@test/package',
                    path: 'npm:@test/package',
                    breakingChanges: [{
                            type: 'export-removed',
                            description: "Removed export 'SomeFunction'",
                            before: 'SomeFunction'
                        }, {
                            type: 'type-changed',
                            description: "Function 'calculateTotal' changed parameter 1 type",
                            before: 'amount: number',
                            after: 'amount: string | number'
                        }],
                    nonBreakingChanges: [{
                            type: 'export-added',
                            description: "Added export 'NewFunction'",
                            details: 'NewFunction'
                        }]
                }],
            summary: 'Breaking changes detected',
            semverImpact: { minimumBump: 'major', reason: 'Breaking changes detected' }
        };
        const output = formatOutput(result, 'console', false);
        const lines = output.split('\n');
        // Find key sections
        const breakingChangesIndex = lines.findIndex(line => line.includes('❌ Breaking changes:'));
        const nonBreakingChangesIndex = lines.findIndex(line => line.includes('✅ Non-breaking changes:'));
        // Verify blank line before breaking changes section
        expect(lines[breakingChangesIndex - 1]).toBe('');
        // Verify blank line between breaking and non-breaking changes
        expect(lines[nonBreakingChangesIndex - 1]).toBe('');
        // Verify no verbose Before/After details are shown
        const beforeLines = lines.filter(line => line.includes('Before:'));
        const afterLines = lines.filter(line => line.includes('After:'));
        expect(beforeLines.length).toBe(0);
        expect(afterLines.length).toBe(0);
    });
    it('verbose mode shows Before/After details', () => {
        const result = {
            hasBreakingChanges: true,
            packages: [{
                    name: '@test/package',
                    path: 'npm:@test/package',
                    breakingChanges: [{
                            type: 'type-changed',
                            description: "Function 'calculateTotal' changed parameter 1 type",
                            before: 'amount: number',
                            after: 'amount: string | number'
                        }],
                    nonBreakingChanges: []
                }],
            summary: 'Breaking changes detected',
            semverImpact: { minimumBump: 'major', reason: 'Breaking changes detected' }
        };
        const output = formatOutput(result, 'console', true); // verbose = true
        // Verify Before/After details are shown in verbose mode
        expect(output).toMatch(/Before: amount: number/);
        expect(output).toMatch(/After: amount: string \| number/);
    });
    it('shows breaking changes when detected', () => {
        const result = {
            hasBreakingChanges: true,
            packages: [{
                    name: 'test-package',
                    path: './packages/test-package',
                    breakingChanges: [{
                            type: 'export-removed',
                            description: 'Removed export: oldFunction',
                            before: 'export { oldFunction }',
                            after: undefined
                        }],
                    nonBreakingChanges: []
                }],
            summary: 'Breaking changes detected',
            semverImpact: { minimumBump: 'major', reason: 'Breaking changes detected' }
        };
        const output = formatOutput(result, 'console', false);
        expect(output).toMatch(/❌ Breaking changes:/);
        // Package name appears in different context, test the actual change instead
        expect(output).toMatch(/Removed export: oldFunction/);
    });
});