deno: `deno test --coverage` doesn't seem accurate

I have the following report for coverage for a function:

      40         407 : export function parseInfo(s: string): DeliveryInfo {
      41         501 :   const tokens = s.split(".");
      42           0 :   if (tokens.length !== 9 && tokens[0] !== "$JS" && tokens[1] !== "ACK") {
      43           0 :     throw new Error(`not js message`);
      44           0 :   }
      45             :   // "$JS.ACK.<stream>.<consumer>.<redeliveryCount><streamSeq><deliverySequence>.<timestamp>.<pending>"
      46         501 :   const di = {} as DeliveryInfo;
      47         501 :   di.stream = tokens[2];
      48         501 :   di.consumer = tokens[3];
      49         501 :   di.redeliveryCount = parseInt(tokens[4], 10);
      50         501 :   di.streamSequence = parseInt(tokens[5], 10);
      51         501 :   di.deliverySequence = parseInt(tokens[6], 10);
      52         501 :   di.timestampNanos = parseInt(tokens[7], 10);
      53         112 :   di.pending = parseInt(tokens[8], 10);
      54         507 :   return di;
      55         413 : }

Notice how lines 42:44 report zero coverage.

But elsewhere:

Deno.test("jsmsg - parse rejects subject is not 9 tokens", () => {
  const fn = (s: string, ok: boolean) => {
    try {
      console.dir(s)
      parseInfo(s);
      if (!ok) {
        fail(`${s} should have failed to parse`);
      }
    } catch (err) {
      if (ok) {
        fail(`${s} shouldn't have failed to parse: ${err.message}`);
      }
    }
  };

  const chunks = `$JS.ACK.stream.consumer.1.2.3.4.5`.split(".");
  for (let i = 1; i <= chunks.length; i++) {
    fn(chunks.slice(0, i).join("."), i === 9);
  }
});

Clearly, the code is executed, so it should leave some sort of trace.

I wonder if there’s some sort of mismatch - my tests live in a tests directory, while the module is elsewhere. Is it possible it is getting skewed by imports?