# Converters
Converters are used to split a target into its component parts, then verify each of those parts.
When a target is split the result is:
* An info file (containing the metadata of the target) serialized as json. File name: `{TestType}.{TestMethod}.info.verified.txt`
* Zero or more documents of a specified extension. File name: `{TestType}.{TestMethod}.{Index}.verified.{Extension}`
## Usage scenarios
* tiff => png per page
* spreadsheet => csv per sheet
* pdf => png per page
## Example
Both the following examples take an input tiff and convert it to:
The info file:
```txt
{
PixelFormat: Format8bppIndexed,
Size: 473, 355
}
```
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Multiple png files:
### Typed converter
This sample uses a typed approach. So the converter acts on an in memory instance matching based on type.
```cs
VerifierSettings.RegisterFileConverter(
canConvert: (target, context) => Equals(target.RawFormat, ImageFormat.Tiff),
conversion: (image, settings) =>
{
var pages = image.GetFrameCount(FrameDimension.Page);
var targets = new List();
for (var index = 0; index < pages; index++)
{
image.SelectActiveFrame(FrameDimension.Page, index);
var page = new MemoryStream();
image.Save(page, ImageFormat.Png);
targets.Add(new("png", page));
}
return new(
info: new
{
image.PixelFormat,
image.Size
},
targets);
});
```
snippet source | anchor
```cs
using var stream = File.OpenRead("sample.tif");
await Verify(Image.FromStream(stream));
```
snippet source | anchor
Note that this sample also uses the optional `canConvert` to ensure that only `Image`s that are tiffs are converted.
```cs
canConvert: (target, context) => Equals(target.RawFormat, ImageFormat.Tiff),
```
snippet source | anchor
### Stream Conversion
This sample uses a extension approach. So the converter acts on a file or stream based on the extension (configured or detected).
```cs
VerifierSettings.RegisterStreamConverter(
extension: "tif",
conversion: (name, stream, settings) =>
{
using var image = Image.FromStream(stream);
var pages = image.GetFrameCount(FrameDimension.Page);
var targets = new List();
for (var index = 0; index < pages; index++)
{
image.SelectActiveFrame(FrameDimension.Page, index);
var page = new MemoryStream();
image.Save(page, ImageFormat.Png);
targets.Add(new("png", page));
}
return new(
info: new
{
image.PixelFormat,
image.Size
},
targets);
});
```
snippet source | anchor
```cs
await VerifyFile("sample.tif");
```
snippet source | anchor
### Cleanup
If cleanup needs to occur after verification a callback can be passes to `ConversionResult`:
```cs
return new(
info: null,
"bin",
stream: File.OpenRead(withStreamRequiringCleanupPath),
cleanup: () =>
{
File.Delete(withStreamRequiringCleanupPath);
return Task.CompletedTask;
});
```
snippet source | anchor
## Shipping
Converters can be shipped as NuGet packages:
* [Verify.Aspose](https://github.com/VerifyTests/VerifyTests.Aspose): Verification of documents (pdf, docx, xlsx, and pptx) via Aspose.
* [Verify.EntityFramework](https://github.com/VerifyTests/Verify.EntityFramework): Verification of EntityFramework bits.
* [Verify.ImageMagick](https://github.com/VerifyTests/Verify.ImageMagick): Verification and comparison of images via [Magick.NET](https://github.com/dlemstra/Magick.NET).
* [Verify.ImageSharp](https://github.com/VerifyTests/Verify.ImageSharp): Verification of images via [ImageSharp](https://github.com/SixLabors/ImageSharp).
* [Verify.NServiceBus](https://github.com/NServiceBusExtensions/Verify.NServiceBus): Verify NServiceBus Test Contexts.
* [Verify.RavenDb](https://github.com/VerifyTests/Verify.RavenDb): Verification of [RavenDb](https://ravendb.net) bits.
* [Verify.SqlServer](https://github.com/VerifyTests/Verify.SqlServer): Verification of SqlServer bits.
* [Verify.Syncfusion](https://github.com/VerifyTests/Verify.Syncfusion): Converts documents (pdf, docx, xlsx, and pptx) to png/csv/text for verification.
* [Verify.Web](https://github.com/VerifyTests/Verify.Web): Verification of web bits.
* [Verify.WinForms](https://github.com/VerifyTests/Verify.WinForms): Verification of WinForms UIs.
* [Verify.Xaml](https://github.com/VerifyTests/Verify.Xaml): Verification of Xaml UIs.