--- title: "Non-Retrying Assertions | Grafana k6 documentation" description: "Synchronous assertions that evaluate immediately" --- > For a curated documentation index, see [llms.txt](/llms.txt). For the complete documentation index, see [llms-full.txt](/llms-full.txt). # Non-Retrying Assertions Non-retrying assertions are synchronous assertions that allow to test any conditions, but do not auto-retry. They are ideal for testing static values, API responses, and any scenario where the expected condition should be true at the moment of evaluation. Non-retrying assertions differ from [retrying assertions](https://grafana.com/docs/k6/v2.3.x/javascript-api/jslib/testing/retrying-assertions/) in that they: - **Evaluate immediately** - They check the condition once and return the result - **Are synchronous** - They don’t need to be awaited and return results immediately - **Have no timeout behavior** - They either pass or fail instantly - **Are ideal for static content** - Perfect for testing values that don’t change over time JavaScript ![Copy code to clipboard](https://grafana.com/media/images/icons/icon-copy-small-2.svg) Copy ```javascript import http from 'k6/http'; import { expect } from 'https://jslib.k6.io/k6-testing/0.6.1/index.js'; export default function () { const response = http.get('https://quickpizza.grafana.com/'); // Immediate assertions expect(response.status).toBe(200); expect(response.body).toBeDefined(); expect(response.body).toBeTruthy(); expect(typeof response.body).toBe('string'); expect(response.body).toContain('Pizza'); } ``` ## When to Use Non-Retrying Assertions Non-retrying assertions are best suited for: - **API response testing** - Checking status codes, response data, headers - **Static values** - Testing constants, configuration values, or computed results - **Data validation** - Verifying object properties, array contents, or data types - **Known state verification** - Checking values that should be immediately available ## Non-retrying assertions methods ### Equality Assertions Expand table | Method | Description | |---------------------------------------------------------------------------------------------------------------|----------------------------------| | [toBe()](https://grafana.com/docs/k6/v2.3.x/javascript-api/jslib/testing/non-retrying-assertions/tobe/) | Exact equality using Object.is() | | [toEqual()](https://grafana.com/docs/k6/v2.3.x/javascript-api/jslib/testing/non-retrying-assertions/toequal/) | Deep equality comparison | ### Truthiness Assertions Expand table | Method | Description | |---------------------------------------------------------------------------------------------------------------------------|------------------------| | [toBeTruthy()](https://grafana.com/docs/k6/v2.3.x/javascript-api/jslib/testing/non-retrying-assertions/tobetruthy/) | Value is truthy | | [toBeFalsy()](https://grafana.com/docs/k6/v2.3.x/javascript-api/jslib/testing/non-retrying-assertions/tobefalsy/) | Value is falsy | | [toBeDefined()](https://grafana.com/docs/k6/v2.3.x/javascript-api/jslib/testing/non-retrying-assertions/tobedefined/) | Value is not undefined | | [toBeUndefined()](https://grafana.com/docs/k6/v2.3.x/javascript-api/jslib/testing/non-retrying-assertions/tobeundefined/) | Value is undefined | | [toBeNull()](https://grafana.com/docs/k6/v2.3.x/javascript-api/jslib/testing/non-retrying-assertions/tobenull/) | Value is null | ### Comparison Assertions Expand table | Method | Description | |---------------------------------------------------------------------------------------------------------------------------------------------|-------------------------------| | [toBeGreaterThan()](https://grafana.com/docs/k6/v2.3.x/javascript-api/jslib/testing/non-retrying-assertions/tobegreaterthan/) | Numeric greater than | | [toBeGreaterThanOrEqual()](https://grafana.com/docs/k6/v2.3.x/javascript-api/jslib/testing/non-retrying-assertions/tobegreaterthanorequal/) | Numeric greater than or equal | | [toBeLessThan()](https://grafana.com/docs/k6/v2.3.x/javascript-api/jslib/testing/non-retrying-assertions/tobelessthan/) | Numeric less than | | [toBeLessThanOrEqual()](https://grafana.com/docs/k6/v2.3.x/javascript-api/jslib/testing/non-retrying-assertions/tobelessthanorequal/) | Numeric less than or equal | | [toBeCloseTo()](https://grafana.com/docs/k6/v2.3.x/javascript-api/jslib/testing/non-retrying-assertions/tobecloseto/) | Floating point comparison | ### Collection Assertions Expand table | Method | Description | |-----------------------------------------------------------------------------------------------------------------------------|---------------------------------------------| | [toContain()](https://grafana.com/docs/k6/v2.3.x/javascript-api/jslib/testing/non-retrying-assertions/tocontain/) | Array/string contains value | | [toContainEqual()](https://grafana.com/docs/k6/v2.3.x/javascript-api/jslib/testing/non-retrying-assertions/tocontainequal/) | Array contains object with matching content | | [toHaveLength()](https://grafana.com/docs/k6/v2.3.x/javascript-api/jslib/testing/non-retrying-assertions/tohavelength/) | Array/string has specific length | ### Property Assertions Expand table | Method | Description | |-----------------------------------------------------------------------------------------------------------------------------|------------------------------| | [toHaveProperty()](https://grafana.com/docs/k6/v2.3.x/javascript-api/jslib/testing/non-retrying-assertions/tohaveproperty/) | Object has specific property | ### Type Assertions Expand table | Method | Description | |-----------------------------------------------------------------------------------------------------------------------------|----------------------------| | [toBeInstanceOf()](https://grafana.com/docs/k6/v2.3.x/javascript-api/jslib/testing/non-retrying-assertions/tobeinstanceof/) | Value is instance of class | ## Common Patterns ### API Response Validation JavaScript ![Copy code to clipboard](https://grafana.com/media/images/icons/icon-copy-small-2.svg) Copy ```javascript export default function () { const response = http.get('https://quickpizza.grafana.com/'); // Response status and headers expect(response.status).toBe(200); expect(response.headers['content-type']).toContain('text/html'); // Response data structure expect(response.body).toBeDefined(); expect(response.body).toBeTruthy(); expect(response.body).toContain('pizza'); expect(response.body).toContain('Pizza'); // Data types expect(typeof response.body).toBe('string'); expect(response.body.length).toBeGreaterThan(0); } ``` ### Data Validation JavaScript ![Copy code to clipboard](https://grafana.com/media/images/icons/icon-copy-small-2.svg) Copy ```javascript export default function () { const userData = { name: 'John Doe', email: 'john@example.com', age: 30, hobbies: ['reading', 'gaming'], address: { city: 'New York', country: 'USA', }, }; // Object structure validation expect(userData).toHaveProperty('name'); expect(userData).toHaveProperty('address.city'); expect(userData.hobbies).toHaveLength(2); // Value validation expect(userData.name).toBeDefined(); expect(userData.email).toContain('@'); expect(userData.age).toBeGreaterThan(0); expect(userData.hobbies).toContain('reading'); } ``` ### Configuration Testing JavaScript ![Copy code to clipboard](https://grafana.com/media/images/icons/icon-copy-small-2.svg) Copy ```javascript export default function () { const config = { apiUrl: __ENV.API_URL || 'https://api.example.com', timeout: parseInt(__ENV.TIMEOUT || '5000'), retries: parseInt(__ENV.RETRIES || '3'), features: (__ENV.FEATURES || 'feature1,feature2').split(','), }; // Configuration validation expect(config.apiUrl).toContain('http'); expect(config.timeout).toBeGreaterThan(0); expect(config.retries).toBeGreaterThanOrEqual(0); expect(config.features).toContain('feature1'); expect(config.features).toHaveLength(2); } ``` ## Error Handling Patterns ### Graceful Error Handling JavaScript ![Copy code to clipboard](https://grafana.com/media/images/icons/icon-copy-small-2.svg) Copy ```javascript export default function () { const response = http.get('https://quickpizza.grafana.com/'); // Check response status first if (response.status === 200) { expect(response.body).toBeDefined(); expect(response.body).toBeTruthy(); expect(response.body).toContain('Pizza'); } else { // Handle error response expect(response.status).toBeGreaterThanOrEqual(400); expect(response.body).toContain('error'); } } ``` - [toBe()](https://grafana.com/docs/k6/v2.3.x/javascript-api/jslib/testing/non-retrying-assertions/tobe/) - [toEqual()](https://grafana.com/docs/k6/v2.3.x/javascript-api/jslib/testing/non-retrying-assertions/toequal/) - [toContain()](https://grafana.com/docs/k6/v2.3.x/javascript-api/jslib/testing/non-retrying-assertions/tocontain/) - [toBeTruthy()](https://grafana.com/docs/k6/v2.3.x/javascript-api/jslib/testing/non-retrying-assertions/tobetruthy/) - [toBeFalsy()](https://grafana.com/docs/k6/v2.3.x/javascript-api/jslib/testing/non-retrying-assertions/tobefalsy/) - [toBeDefined()](https://grafana.com/docs/k6/v2.3.x/javascript-api/jslib/testing/non-retrying-assertions/tobedefined/) - [toBeGreaterThan()](https://grafana.com/docs/k6/v2.3.x/javascript-api/jslib/testing/non-retrying-assertions/tobegreaterthan/) - [toBeCloseTo()](https://grafana.com/docs/k6/v2.3.x/javascript-api/jslib/testing/non-retrying-assertions/tobecloseto/) - [toHaveLength()](https://grafana.com/docs/k6/v2.3.x/javascript-api/jslib/testing/non-retrying-assertions/tohavelength/) - [toHaveProperty()](https://grafana.com/docs/k6/v2.3.x/javascript-api/jslib/testing/non-retrying-assertions/tohaveproperty/) - [toBeGreaterThanOrEqual()](https://grafana.com/docs/k6/v2.3.x/javascript-api/jslib/testing/non-retrying-assertions/tobegreaterthanorequal/) - [toBeLessThan()](https://grafana.com/docs/k6/v2.3.x/javascript-api/jslib/testing/non-retrying-assertions/tobelessthan/) - [toBeNull()](https://grafana.com/docs/k6/v2.3.x/javascript-api/jslib/testing/non-retrying-assertions/tobenull/) - [toBeUndefined()](https://grafana.com/docs/k6/v2.3.x/javascript-api/jslib/testing/non-retrying-assertions/tobeundefined/) - [toContainEqual()](https://grafana.com/docs/k6/v2.3.x/javascript-api/jslib/testing/non-retrying-assertions/tocontainequal/) - [toBeLessThanOrEqual()](https://grafana.com/docs/k6/v2.3.x/javascript-api/jslib/testing/non-retrying-assertions/tobelessthanorequal/) - [toBeInstanceOf()](https://grafana.com/docs/k6/v2.3.x/javascript-api/jslib/testing/non-retrying-assertions/tobeinstanceof/) - [toBeNaN()](https://grafana.com/docs/k6/v2.3.x/javascript-api/jslib/testing/non-retrying-assertions/tobenan/)