Decouple `join-order.ts` from VS Code for testing purposes

extensions/ql-vscode/src/extension.ts

@@ -33,6 +33,7 @@ import {
   CliConfigListener,
   DistributionConfigListener,
   isCanary,
+  joinOrderWarningThreshold,
   MAX_QUERIES,
   QueryHistoryConfigListener,
   QueryServerConfigListener
@@ -518,7 +519,7 @@ async function activateWithInstalledDistribution(
   void logger.log('Initializing evaluation log scanners.');
   const logScannerService = new LogScannerService(qhm);
   ctx.subscriptions.push(logScannerService);
-  ctx.subscriptions.push(logScannerService.scanners.registerLogScannerProvider(new JoinOrderScannerProvider()));
+  ctx.subscriptions.push(logScannerService.scanners.registerLogScannerProvider(new JoinOrderScannerProvider(() => joinOrderWarningThreshold())));
 
   void logger.log('Reading query history');
   await qhm.readQueryHistory();

extensions/ql-vscode/src/log-insights/join-order.ts

@@ -1,5 +1,4 @@
 import * as I from 'immutable';
-import { joinOrderWarningThreshold } from '../config';
 import { EvaluationLogProblemReporter, EvaluationLogScanner, EvaluationLogScannerProvider } from './log-scanner';
 import { InLayer, ComputeRecursive, SummaryEvent, PipelineRun, ComputeSimple } from './log-summary';
 
@@ -453,8 +452,11 @@ class JoinOrderScanner implements EvaluationLogScanner {
 }
 
 export class JoinOrderScannerProvider implements EvaluationLogScannerProvider {
+  constructor(private readonly getThreshdold: () => number) {
+  }
+
   public createScanner(problemReporter: EvaluationLogProblemReporter): EvaluationLogScanner {
-    const threshold = joinOrderWarningThreshold();
+    const threshold = this.getThreshdold();
     return new JoinOrderScanner(problemReporter, threshold);
   }
 }

extensions/ql-vscode/test/pure-tests/log-scanner.test.ts

@@ -31,7 +31,7 @@ class TestProblemReporter implements EvaluationLogProblemReporter {
 describe('log scanners', function() {
   it('should detect bad join orders', async function() {
     const scanners = new EvaluationLogScannerSet();
-    scanners.registerLogScannerProvider(new JoinOrderScannerProvider());
+    scanners.registerLogScannerProvider(new JoinOrderScannerProvider(() => 50));
     const summaryPath = path.join(__dirname, 'evaluator-log-summaries/bad-join-order.jsonl');
     const problemReporter = new TestProblemReporter();
     await scanners.scanLog(summaryPath, problemReporter);