feat: add tests for mock variable interpolation in interpolate function (#4507)

* feat: add tests for mock variable interpolation in interpolate function
* test: enhance mock variable interpolation tests for additional types and JSON validation

---------
Co-authored-by: sanjai0py <sanjailucifer666@gmail.com>

packages/bruno-common/src/interpolate/index.spec.ts

@@ -354,3 +354,68 @@ describe('interpolate - recursive', () => {
     }`);
   });
 });
+
+describe('interpolate - mock variable interpolation', () => {
+  it('should replace mock variables with generated values', () => {
+    const inputString = '{{$randomInt}}, {{$randomIP}}, {{$randomIPV4}}, {{$randomIPV6}}, {{$randomBoolean}}';
+
+    const result = interpolate(inputString, {});
+
+    // Validate the result using regex patterns
+    const randomIntPattern = /^\d+$/;
+    const randomIPPattern = /^([\da-f]{1,4}:){7}[\da-f]{1,4}$|^(\d{1,3}\.){3}\d{1,3}$/;
+    const randomIPV4Pattern = /^(\d{1,3}\.){3}\d{1,3}$/;
+    const randomIPV6Pattern = /^([\da-f]{1,4}:){7}[\da-f]{1,4}$/;
+    const randomBooleanPattern = /^(true|false)$/;
+
+    const [randomInt, randomIP, randomIPV4, randomIPV6, randomBoolean] = result.split(', ');
+
+    expect(randomIntPattern.test(randomInt)).toBe(true);
+    expect(randomIPPattern.test(randomIP)).toBe(true);
+    expect(randomIPV4Pattern.test(randomIPV4)).toBe(true);
+    expect(randomIPV6Pattern.test(randomIPV6)).toBe(true);
+    expect(randomBooleanPattern.test(randomBoolean)).toBe(true);
+  });;
+
+  it('should leave mock variables unchanged if no corresponding function exists', () => {
+    const inputString = 'Random number: {{$nonExistentMock}}';
+
+    const result = interpolate(inputString, {});
+
+    expect(result).toBe('Random number: {{$nonExistentMock}}');
+  });
+
+  it('should escape special characters in mock variable values and produce valid JSON when escapeJSONStrings is true', () => {
+    const inputString = '{"escapedValue": "{{$randomLoremParagraphs}}"}';
+  
+    expect(() => {
+      const result = interpolate(inputString, {}, { escapeJSONStrings: true });
+      JSON.parse(result); // This should not throw an error
+    }).not.toThrow();
+  });
+
+  it('should not produce valid JSON when escapeJSONStrings is false', () => {
+    const inputString = '{"escapedValue": "{{$randomLoremParagraphs}}"}';
+  
+    expect(() => {
+      const result = interpolate(inputString, {}, { escapeJSONStrings: false });
+      JSON.parse(result); // This should throw an error
+    }).toThrow();
+  });
+
+  it('should throw an error when producing invalid JSON regardless of escapeJSONStrings option', () => {
+    const inputString = '{"escapedValue": "{{$randomLoremParagraphs}}"}';
+  
+    // Test without providing the options argument
+    expect(() => {
+      const result = interpolate(inputString, {});
+      JSON.parse(result); // This should throw an error
+    }).toThrow();
+  
+    // Test with escapeJSONStrings explicitly set to false
+    expect(() => {
+      const result = interpolate(inputString, {}, { escapeJSONStrings: false });
+      JSON.parse(result); // This should throw an error
+    }).toThrow();
+  });
+});