message: test(): fixes for ava 0.19
diff: -import test, { ContextualTestContext } from 'ava';
  +import test, { TestContext } from 'ava';
  import * as chalk from 'chalk';
  import * as diff from 'diff';
  @@ -18,7 +18,7 @@ function normalize(input: string): string {
  .replace(/ => /g, '=>');
  }
  -function textDiff(t: ContextualTestContext, actual: string, expected: string): void {
  +function textDiff(t: TestContext, actual: string, expected: string): void {
  if (diff.diffChars(normalize(expected), normalize(actual)).length > 1) {
  const differences = diff.diffChars(expected, actual);
  const result = differences
  @@ -28,10 +28,12 @@ function textDiff(t: ContextualTestContext, actual: string, expected: string): v
  })
  .join('');
  t.fail(`\n${result}`);
  + } else {
  + t.pass();
  }
  }
  -function compare(t: ContextualTestContext, moduleName: string|null, file1: string, file2: string,
  +function compare(t: TestContext, moduleName: string|null, file1: string, file2: string,
  opts: react2dts.IOptions = {}, reactImport = 'react'): void {
  textDiff(
  t,
  