public async Task <UrlAppearanceCount> CountAppearances([FromBody] UrlAppearanceQuery query)
{
int count;
var tokenSource = new CancellationTokenSource();
tokenSource.CancelAfter(CancelAfterMilliSecond);
if (!_memoryCache.TryGetValue((query.Keywords, query.Url), out count))
{
try
{
count = await _scraper.SearchKeywordsAndCountUrlAppearances(query.Keywords, query.Url, tokenSource.Token);
_memoryCache.Set((query.Keywords, query.Url), count, DefaultMemoryCacheEntryOptions);
}
catch (InvalidOperationException ex)
{
_logger.LogError(ex, "Scraper failed, did search engine change its layout?");
return(GetUrlApperanceCount(query, ""));
}
}
return(GetUrlApperanceCount(query, count.ToString()));
}
private UrlAppearanceCount GetUrlApperanceCount(UrlAppearanceQuery query, string count)
{
return(new UrlAppearanceCount
{
Keywords = query.Keywords,
Url = query.Url,
Count = count
});
}
public async Task CountAppearances_UsesCache_WhenCacheHasEntryAndNotExpired()
{
// Arrange
var query = new UrlAppearanceQuery
{
Keywords = "abc",
Url = "def"
};
var expected = 1;
var _memoryCacheWithHit = MockMemoryCacheService.GetMemoryCache(expected, true);
var controller = new UrlAppearanceController(_options.Object, _memoryCacheWithHit, _scraper.Object, _logger.Object);
// Act
var result = await controller.CountAppearances(query);
// Assert
_scraper.Verify(s => s.SearchKeywordsAndCountUrlAppearances(It.IsAny <string>(), It.IsAny <string>(), It.IsAny <CancellationToken>()), Times.Never);
Assert.Equal("abc", result.Keywords);
Assert.Equal("def", result.Url);
Assert.Equal("1", result.Count);
}
public async Task CountAppearances_DoesNotUsesCache_WhenNoCacheEntry()
{
// Arrange
var query = new UrlAppearanceQuery
{
Keywords = "abc",
Url = "def"
};
var _memoryCacheWithMiss = MockMemoryCacheService.GetMemoryCache(null, false);
_scraper.Setup(s => s.SearchKeywordsAndCountUrlAppearances(It.IsAny <string>(), It.IsAny <string>(), It.IsAny <CancellationToken>())).ReturnsAsync(2);
var controller = new UrlAppearanceController(_options.Object, _memoryCacheWithMiss, _scraper.Object, _logger.Object);
// Act
var result = await controller.CountAppearances(query);
// Assert
_scraper.Verify(s => s.SearchKeywordsAndCountUrlAppearances(It.IsAny <string>(), It.IsAny <string>(), It.IsAny <CancellationToken>()), Times.Once);
Assert.Equal("abc", result.Keywords);
Assert.Equal("def", result.Url);
Assert.Equal("2", result.Count);
}
