test_runner: fix typescript coverage

Author: MoLow

lib/internal/test_runner/coverage.js

@@ -313,7 +313,7 @@ function mapRangeToLines(range, lines) {
     mid = MathFloor((start + end) / 2);
     let line = lines[mid];
 
-    if (startOffset >= line.startOffset && startOffset <= line.endOffset) {
+    if (startOffset >= line?.startOffset && startOffset <= line?.endOffset) {
       while (endOffset > line?.startOffset) {
         // If the range is not covered, and the range covers the entire line,
         // then mark that line as not covered.
@@ -333,7 +333,7 @@ function mapRangeToLines(range, lines) {
       }
 
       break;
-    } else if (startOffset >= line.endOffset) {
+    } else if (startOffset >= line?.endOffset) {
       start = mid + 1;
     } else {
       end = mid - 1;

lib/internal/test_runner/test.js

@@ -737,6 +737,7 @@ class Test extends AsyncResource {
       this.reported = true;
       reporter.plan(nesting, loc, harness.counters.topLevel);
 
+      const coverage = harness.coverage(); // Call this before printing diagnostics, since failure to collect coverage is a diagnostic.
       for (let i = 0; i < diagnostics.length; i++) {
         reporter.diagnostic(nesting, loc, diagnostics[i]);
       }
@@ -750,8 +751,6 @@ class Test extends AsyncResource {
       reporter.diagnostic(nesting, loc, `todo ${harness.counters.todo}`);
       reporter.diagnostic(nesting, loc, `duration_ms ${this.duration()}`);
 
-      const coverage = harness.coverage();
-
       if (coverage) {
         reporter.coverage(nesting, loc, coverage);
       }