feat: Add tests for watch functionality in CLI to handle input file changes

Author: swedishkid

test/cli.test.js

@@ -1,7 +1,8 @@
 import { expect } from 'chai';
-import { exec } from 'child_process';
+import { exec, spawn } from 'child_process';
 import path from 'path';
 import { fileURLToPath } from 'url';
+import { writeFileSync, unlinkSync, existsSync, readFileSync } from 'fs';
 
 const __filename = fileURLToPath(import.meta.url);
 const __dirname = path.dirname(__filename);
@@ -23,4 +24,114 @@ describe('CLI', () => {
       done();
     });
   });
+
+  describe('watch functionality', () => {
+    const testInputPath = path.join(__dirname, 'test-input.json');
+    const testOutputPath = path.join(__dirname, 'test-output.js');
+    const sampleSpec = {
+      "openapi": "3.0.1",
+      "info": { "title": "Watch Test API", "version": "1.0.0" },
+      "paths": {
+        "/test": {
+          "get": {
+            "operationId": "getTest",
+            "responses": { "200": { "description": "OK" } }
+          }
+        }
+      }
+    };
+
+    beforeEach(() => {
+      writeFileSync(testInputPath, JSON.stringify(sampleSpec, null, 2));
+    });
+
+    afterEach(() => {
+      [testInputPath, testOutputPath].forEach(file => {
+        if (existsSync(file)) {
+          unlinkSync(file);
+        }
+      });
+    });
+
+    it('should regenerate client when input file changes', function(done) {
+      this.timeout(5000);
+      
+      const cliPath = path.join(__dirname, '../bin/cli.js');
+      const child = spawn('node', [cliPath, 'generate', '-i', testInputPath, '-o', testOutputPath, '--watch'], {
+        stdio: ['pipe', 'pipe', 'pipe']
+      });
+
+      let outputReceived = false;
+      let regenerateReceived = false;
+
+      child.stdout.on('data', (data) => {
+        const output = data.toString();
+        
+        if (output.includes('✓ Fetch client generated successfully!') && !outputReceived) {
+          outputReceived = true;
+          expect(existsSync(testOutputPath)).to.be.true;
+          
+          setTimeout(() => {
+            const updatedSpec = { ...sampleSpec };
+            updatedSpec.info.title = "Updated Watch Test API";
+            writeFileSync(testInputPath, JSON.stringify(updatedSpec, null, 2));
+          }, 100);
+        }
+        
+        if (output.includes('File changed, regenerating...') && !regenerateReceived) {
+          regenerateReceived = true;
+        }
+        
+        if (outputReceived && regenerateReceived && output.includes('✓ Fetch client generated successfully!')) {
+          const clientCode = readFileSync(testOutputPath, 'utf8');
+          expect(clientCode).to.include('class ApiClient');
+          child.kill('SIGINT');
+          done();
+        }
+      });
+
+      child.stderr.on('data', (data) => {
+        console.error('CLI stderr:', data.toString());
+      });
+
+      child.on('error', (error) => {
+        done(error);
+      });
+    });
+
+    it('should handle watch mode with invalid input gracefully', function(done) {
+      this.timeout(3000);
+      
+      const cliPath = path.join(__dirname, '../bin/cli.js');
+      const child = spawn('node', [cliPath, 'generate', '-i', testInputPath, '-o', testOutputPath, '--watch'], {
+        stdio: ['pipe', 'pipe', 'pipe']
+      });
+
+      let initialGeneration = false;
+
+      child.stdout.on('data', (data) => {
+        const output = data.toString();
+        
+        if (output.includes('✓ Fetch client generated successfully!') && !initialGeneration) {
+          initialGeneration = true;
+          
+          setTimeout(() => {
+            writeFileSync(testInputPath, 'invalid json');
+          }, 100);
+        }
+      });
+
+      child.stderr.on('data', (data) => {
+        const errorOutput = data.toString();
+        if (errorOutput.includes('Error generating client:')) {
+          child.kill('SIGINT');
+          done();
+        }
+      });
+
+      child.on('error', (error) => {
+        done(error);
+      });
+    });
+  });
 });