code: function (entry) {
      const re = /(%\d)/g;
      const [key, translation] = entry;
      const enMatch = en[key].match(re);
      const tMatch = translation.match(re);
      const enCount = enMatch ? enMatch.length : 0;
      const tCount = tMatch ? tMatch.length : 0;
      assert.strictEqual(tCount, enCount, `${key}:${en[key]} - "${translation}" placeholder mismatch`);
      if (enCount > 0) {
  
        assert.notStrictEqual(tMatch, null, `${key} is missing a placeholder: ${translation}`);
        assert.strictEqual(
            tMatch.sort().toString(),
            enMatch.sort().toString(),
            `${key} is missing or has duplicate placeholders: ${translation}`
        );
      }
      assert.strictEqual(translation.match(/[\n]/), null, `${key} contains a newline character ${translation}`);
  }
docs: Check that translation is valid: entry: array [key, translation]  corresponding to a single string from <locale>.json - messages with placeholders have the same number of placeholders - messages must not have newlines embedded