fix: JSON validation for unquoted @placeholders@

src/test/ConfigTemplate.test.ts

@@ -0,0 +1,108 @@
+import { describe, it, expect } from 'vitest';
+
+describe('JSON Validation with @placeholders@', () => {
+  /**
+   * Helper function that mimics the validation logic in ConfigTemplate.tsx
+   */
+  function validateJsonWithPlaceholders(value: string): { valid: boolean; error?: string } {
+    try {
+      if (!value.trim()) {
+        return { valid: true };
+      }
+
+      // This is the current implementation from ConfigTemplate.tsx
+      // Replace ALL @...@ patterns with "1" (valid for both string and numeric contexts)
+      const sanitizedValue = value.replace(/@[^@]+@/g, '1');
+
+      JSON.parse(sanitizedValue);
+      return { valid: true };
+    } catch (e) {
+      return { valid: false, error: (e as Error).message };
+    }
+  }
+
+  it('should validate quoted placeholders', () => {
+    const json = `{
+      "Host": "@host@",
+      "Port": "@port@"
+    }`;
+    
+    const result = validateJsonWithPlaceholders(json);
+    expect(result.valid).toBe(true);
+  });
+
+  it('should validate unquoted placeholders', () => {
+    const json = `{
+      "Host": "@host@",
+      "Port": @port@
+    }`;
+    
+    const result = validateJsonWithPlaceholders(json);
+    expect(result.valid).toBe(true);
+  });
+
+  it('should validate mixed quoted and unquoted placeholders', () => {
+    const json = `{
+      "Host": "@host@",
+      "Port": @port@,
+      "ApiPath": "@host@:@port@/v1/data",
+      "MessageBroker": {
+        "hosts": @MessageBrokerHosts@
+      }
+    }`;
+    
+    const result = validateJsonWithPlaceholders(json);
+    expect(result.valid).toBe(true);
+  });
+
+  it('should validate placeholders inside strings (URLs)', () => {
+    const json = `{
+      "ApiUrl": "http://@host@:@port@/api"
+    }`;
+    
+    const result = validateJsonWithPlaceholders(json);
+    expect(result.valid).toBe(true);
+  });
+
+  it('should validate complex real-world template', () => {
+    const json = `{
+      "Host": "@host@",
+      "Port": @port@,
+
+      "ApiPath": "@host@:@port@/v1/data",
+
+      "MessageBroker": {
+        "hosts": @MessageBrokerHosts@
+      },
+
+      "basePath": "./@env_name@/in",
+
+      "NoParam": "@no_param@"
+    }`;
+    
+    const result = validateJsonWithPlaceholders(json);
+    expect(result.valid).toBe(true);
+  });
+
+  it('should reject invalid JSON structure', () => {
+    const json = `{
+      "Host": "@host@",
+      "Port": @port@
+      "Missing": "comma"
+    }`;
+    
+    const result = validateJsonWithPlaceholders(json);
+    expect(result.valid).toBe(false);
+    expect(result.error).toContain('Expected');
+  });
+
+  it('should handle empty value', () => {
+    const result = validateJsonWithPlaceholders('');
+    expect(result.valid).toBe(true);
+  });
+
+  it('should handle whitespace only', () => {
+    const result = validateJsonWithPlaceholders('   \n\t  ');
+    expect(result.valid).toBe(true);
+  });
+});