runTest = file => {
      const T = {
        is: (e, r, text) => t.is(e, r, file + ' - ' + text),
      };
      try {
        return harness(path.resolve(__dirname, '../../syntax', file))(T).catch(
          e => {
            // eslint-disable-next-line
            console.error(
              `  Runtime failure for syntax test at ${file}\n\n  ${e.message}`
            );
            throw e;
          }
        );
      } catch (e) {
        // eslint-disable-next-line
        console.error(
          `  Failed syntax test compilation at ${file} ${e.message}`
        );
        return Promise.reject(new Error(`Failed at ${file}`));
      }
    }
The bootstrap logic for testing all of the syntax features
of the compiler.