@mojaloop/central-services-shared/test/unit/healthCheck/HealthCheck.test.js

Shared code for mojaloop central services

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'use strict'

const Test = require('tapes')(require('tape'))
const Sinon = require('sinon')
const Joi = require('joi')
const Metrics = require('@mojaloop/central-services-metrics')

const HealthCheck = require('../../../src/healthCheck').HealthCheck

Test('HealthCheck test', healthCheckTest => {
  let sandbox

  healthCheckTest.beforeEach(t => {
    sandbox = Sinon.createSandbox()
    t.end()
  })

  healthCheckTest.afterEach(t => {
    sandbox.restore()
    t.end()
  })

  healthCheckTest.test('getHealth', getHealthTest => {
    getHealthTest.test('gets the health with empty serviceChecks', async test => {
      // Arrange
      const healthCheck = new HealthCheck({ version: '1.0.0' }, [])
      const schema = Joi.compile({
        status: Joi.string().valid('OK').required(),
        uptime: Joi.number().required(),
        startTime: Joi.date().iso().required(),
        versionNumber: Joi.string().required(),
        services: Joi.array().required()
      })
      const expectedServices = []

      // Act
      const response = await healthCheck.getHealth()

      // Assert
      const validationResult = Joi.attempt(response, schema) // We use Joi to validate the results as they rely on timestamps that are variable
      test.equal(validationResult.error, undefined, 'The response matches the validation schema')
      test.deepEqual(response.services, expectedServices, 'The sub-services are correct')
      test.end()
    })

    getHealthTest.test('gets the health with two sub-services', async test => {
      // Arrange
      const healthCheck = new HealthCheck({ version: '1.0.0' }, [
        async () => ({ name: 'datastore', status: 'OK' }),
        async () => ({ name: 'broker', status: 'OK' })
      ])
      const schema = Joi.compile({
        status: Joi.string().valid('OK').required(),
        uptime: Joi.number().required(),
        startTime: Joi.date().iso().required(),
        versionNumber: Joi.string().required(),
        services: Joi.array().required()
      })
      const expectedServices = [
        { name: 'datastore', status: 'OK' },
        { name: 'broker', status: 'OK' }
      ]

      // Act
      const response = await healthCheck.getHealth()

      // Assert
      const validationResult = Joi.attempt(response, schema) // We use Joi to validate the results as they rely on timestamps that are variable
      test.equal(validationResult.error, undefined, 'The response matches the validation schema')
      test.deepEqual(response.services, expectedServices, 'The sub-services are correct')
      test.end()
    })

    getHealthTest.test('is down if a sub-service check throws', async test => {
      // Arrange
      const healthCheck = new HealthCheck({ version: '1.0.0' }, [
        async () => { throw new Error('Get health failed') },
        async () => ({ name: 'broker', status: 'OK' })
      ])
      const schema = Joi.compile({
        status: Joi.string().valid('DOWN').required(),
        uptime: Joi.number().required(),
        startTime: Joi.date().iso().required(),
        versionNumber: Joi.string().required()
      })

      // Act
      const response = await healthCheck.getHealth()

      // Assert
      const validationResult = Joi.attempt(response, schema) // We use Joi to validate the results as they rely on timestamps that are variable
      test.equal(validationResult.error, undefined, 'The response matches the validation schema')
      test.end()
    })

    getHealthTest.end()
  })

  healthCheckTest.test('evaluateServiceHealth', evaluateServiceHealthTest => {
    evaluateServiceHealthTest.test('passes if there are no services', async test => {
      // Arrange
      const services = []
      const expected = true

      // Act
      const result = HealthCheck.evaluateServiceHealth(services)

      // Assert
      test.equal(result, expected, 'Service should be healthy')
      test.end()
    })

    evaluateServiceHealthTest.test('passes if nothing is down', async test => {
      // Arrange
      const services = [
        { name: 'datastore', status: 'OK' },
        { name: 'broker', status: 'OK' }
      ]
      const expected = true

      // Act
      const result = HealthCheck.evaluateServiceHealth(services)

      // Assert
      test.equal(result, expected, 'Service should be healthy')
      test.end()
    })

    evaluateServiceHealthTest.test('fails if anything is down', async test => {
      // Arrange
      const services = [
        { name: 'broker', status: 'DOWN' },
        { name: 'datastore', status: 'OK' }
      ]
      const expected = false

      // Act
      const result = HealthCheck.evaluateServiceHealth(services)

      // Assert
      test.equal(result, expected, 'Service should be unhealthy')
      test.end()
    })

    evaluateServiceHealthTest.end()
  })

  healthCheckTest.test('getHealth metrics', metricsTest => {
    let metricsMock

    metricsTest.beforeEach(t => {
      metricsMock = {
        getCounter: Sinon.stub().returns({ inc: Sinon.spy() })
      }
      // Mock Metrics
      sandbox.stub(Metrics, 'getCounter').callsFake(metricsMock.getCounter)
      t.end()
    })

    metricsTest.afterEach(t => {
      sandbox.restore()
      t.end()
    })

    metricsTest.test('increments counter when unhealthy', async test => {
      // Arrange
      const healthCheck = new HealthCheck({ version: '1.0.0' }, [
        async () => ({ status: 'DOWN', name: 'datastore' })
      ])
      // Act
      await healthCheck.getHealth()
      // Assert
      test.ok(metricsMock.getCounter.calledWith('app_critical_total'), 'getCounter called')
      // Subservice counter should be incremented
      test.deepEqual(metricsMock.getCounter().inc.firstCall.args, [{ service: 'datastore' }], 'counter incremented for datastore service')
      // General counter should be incremented
      test.deepEqual(metricsMock.getCounter().inc.secondCall.args, [{ service: 'general' }], 'counter incremented for general service')
      test.end()
    })

    metricsTest.test('increments counter for multiple sub-services with mixed health', async test => {
      // Arrange
      const healthCheck = new HealthCheck({ version: '1.0.0' }, [
        async () => ({ status: 'OK', name: 'datastore' }),
        async () => ({ status: 'DOWN', name: 'broker' }),
        async () => ({ status: 'OK', name: 'cache' })
      ])
      // Act
      await healthCheck.getHealth()
      // Assert
      // Subservice counter incremented for DOWN service
      test.deepEqual(metricsMock.getCounter().inc.firstCall.args, [{ service: 'broker' }], 'counter incremented for broker')
      // General counter incremented
      test.deepEqual(metricsMock.getCounter().inc.secondCall.args, [{ service: 'general' }], 'counter incremented for general service')
      test.equal(metricsMock.getCounter().inc.callCount, 2, 'getCounter.inc called for each DOWN service and general')
      test.end()
    })

    metricsTest.test('handles errors thrown in setGeneralMetrics gracefully', async test => {
      // Arrange
      const healthCheck = new HealthCheck({ version: '1.0.0' }, [
        async () => ({ status: 'OK', name: 'datastore' })
      ])
      // Patch setGeneralMetrics to throw
      const origSetGeneralMetrics = healthCheck.setGeneralMetrics
      healthCheck.setGeneralMetrics = () => { throw new Error('General metrics error') }
      // Act & Assert
      try {
        await healthCheck.getHealth()
        test.pass('No error thrown when setGeneralMetrics throws')
      } catch (err) {
        test.fail('Should not throw when setGeneralMetrics throws')
      }
      // Restore
      healthCheck.setGeneralMetrics = origSetGeneralMetrics
      test.end()
    })

    metricsTest.test('does not call getCounter if no subservice is DOWN', async test => {
      // Arrange
      const healthCheck = new HealthCheck({ version: '1.0.0' }, [
        async () => ({ status: 'OK', name: 'datastore' }),
        async () => ({ status: 'OK', name: 'broker' })
      ])
      // Act
      await healthCheck.getHealth()
      // Assert
      test.equal(metricsMock.getCounter().inc.callCount, 0, 'getCounter.inc not called when all services are healthy')
      test.end()
    })

    metricsTest.test('calls getCounter only for DOWN subservices', async test => {
      // Arrange
      const healthCheck = new HealthCheck({ version: '1.0.0' }, [
        async () => ({ status: 'DOWN', name: 'datastore' }),
        async () => ({ status: 'OK', name: 'broker' }),
        async () => ({ status: 'DOWN', name: 'cache' })
      ])
      // Act
      await healthCheck.getHealth()
      // Assert
      test.deepEqual(metricsMock.getCounter().inc.getCall(0).args, [{ service: 'datastore' }], 'counter incremented for datastore')
      test.deepEqual(metricsMock.getCounter().inc.getCall(1).args, [{ service: 'cache' }], 'counter incremented for cache')
      test.deepEqual(metricsMock.getCounter().inc.getCall(2).args, [{ service: 'general' }], 'counter incremented for general')
      test.equal(metricsMock.getCounter().inc.callCount, 3, 'getCounter.inc called for each DOWN service and general')
      test.end()
    })

    metricsTest.test('handles errors thrown in setSubServiceMetrics gracefully', async test => {
      // Arrange
      const healthCheck = new HealthCheck({ version: '1.0.0' }, [
        async () => ({ status: 'DOWN', name: 'datastore' })
      ])
      // Stub Metrics.getCounter to throw when called
      sandbox.restore() // Remove previous stubs
      const getCounterStub = sandbox.stub(Metrics, 'getCounter').throws(new Error('Subservice metrics error'))
      // Stub Logger.error to spy on error logging
      const loggerErrorStub = sandbox.stub(require('@mojaloop/central-services-logger'), 'error')
      // Act
      await healthCheck.getHealth()
      // Assert
      test.ok(getCounterStub.called, 'getCounter called and throws')
      test.ok(loggerErrorStub.called, 'Logger.error called when setSubServiceMetrics throws')
      test.ok(loggerErrorStub.firstCall.args[0].includes('Failed to set subservice metrics'), 'Correct error message logged')
      loggerErrorStub.restore()
      test.end()
    })
    metricsTest.end()
  })
  healthCheckTest.end()
})