fix: make runSuite proceed to completion when no checks are defined (#…

…205)

Fixes #204

packages/check-core/src/perf/perf-stats.ts

@@ -15,6 +15,15 @@ export class PerfStats {
   }
 
   toReport(): PerfReport {
+    if (this.times.length === 0) {
+      return {
+        minTime: 0,
+        maxTime: 0,
+        avgTime: 0,
+        allTimes: []
+      }
+    }
+
     // Get the absolute min and max times, just for informational
     // purposes (these will be thrown out before computing the average)
     const minTime = Math.min(...this.times)

packages/check-core/src/suite/suite-runner.spec.ts

@@ -7,10 +7,12 @@ import { outputVar } from '../check/_mocks/mock-check-dataset'
 import { inputVar } from '../check/_mocks/mock-check-scenario'
 import { createConfig } from '../config/config'
 import type { Config, ConfigOptions } from '../config/config-types'
+import type { SuiteReport } from './suite-report'
 import type { RunSuiteCallbacks } from './suite-runner'
 import { runSuite } from './suite-runner'
 
 interface MockConfigOptions {
+  emptyTests?: boolean
   invalidTests?: boolean
   throwInCurrentGetDatasets?: boolean
 }
@@ -56,7 +58,9 @@ function mockBundle(mockOptions: MockConfigOptions): Bundle {
 
 async function mockConfig(mockOptions: MockConfigOptions): Promise<Config> {
   let tests: string[]
-  if (mockOptions.invalidTests === true) {
+  if (mockOptions.emptyTests === true) {
+    tests = []
+  } else if (mockOptions.invalidTests === true) {
     tests = ['INVALID']
   } else {
     const test = `
@@ -111,6 +115,34 @@ describe('runSuite', () => {
     expect(progressPcts).toEqual([0, 0.5, 1])
   })
 
+  it('should notify progress and completion callbacks even when there are no tests', async () => {
+    const config = await mockConfig({ emptyTests: true })
+
+    const progressPcts: number[] = []
+    const report: SuiteReport = await new Promise((resolve, reject) => {
+      const callbacks: RunSuiteCallbacks = {
+        onProgress: pct => {
+          progressPcts.push(pct)
+        },
+        onComplete: suiteReport => {
+          resolve(suiteReport)
+        },
+        onError: () => {
+          reject(new Error('onError should not be called'))
+        }
+      }
+      runSuite(config, callbacks)
+    })
+
+    expect(report).toEqual({
+      checkReport: {
+        groups: []
+      },
+      compareReport: undefined
+    })
+    expect(progressPcts).toEqual([0, 1])
+  })
+
   it('should notify error callback if there was an error', async () => {
     const config = await mockConfig({ invalidTests: true })
 

packages/check-core/src/suite/suite-runner.ts

@@ -119,12 +119,35 @@ class SuiteRunner {
       }
     }
 
-    // Schedule the tasks.  The ref data tasks must be processed first so that
+    // Plan the data tasks.  The ref data tasks must be processed first so that
     // the reference data is available in memory when checks are performed.
     const refDataPlan = refDataPlanner.buildPlan()
     const dataPlan = dataPlanner.buildPlan()
     const dataRequests = [...refDataPlan.requests, ...dataPlan.requests]
     const taskCount = dataRequests.length
+    if (taskCount === 0) {
+      // There are no checks or comparison tests; notify completion callback
+      // with empty reports
+      let compareReport: CompareReport
+      if (this.config.compare) {
+        compareReport = {
+          datasetReports: [],
+          perfReportL: this.perfStatsL.toReport(),
+          perfReportR: this.perfStatsR.toReport()
+        }
+      }
+      this.cancel()
+      this.callbacks.onProgress?.(1)
+      this.callbacks.onComplete?.({
+        checkReport: {
+          groups: []
+        },
+        compareReport
+      })
+      return
+    }
+
+    // Schedule a task for each data request
     let tasksCompleted = 0
     let dataTaskId = 1
     for (const dataRequest of dataRequests) {