Verify a schema as a Mermaid diagram in markdown, svg or png

.gitattributes

@@ -3,6 +3,7 @@
 *.snk binary
 
 *.verified.* text eol=lf working-tree-encoding=UTF-8
+*.verified.png binary
 
 .editorconfig text eol=lf working-tree-encoding=UTF-8
 *.sln.DotSettings text eol=lf working-tree-encoding=UTF-8

readme.md

@@ -69,7 +69,7 @@ await Verify(connection)
     // include only tables and views
     .SchemaIncludes(DbObjects.Tables | DbObjects.Views);
 ```
-<sup><a href='/src/Tests/Tests.cs#L705-L711' title='Snippet source file'>snippet source</a> | <a href='#snippet-SchemaInclude' title='Start of snippet'>anchor</a></sup>
+<sup><a href='/src/Tests/Tests.cs#L753-L759' title='Snippet source file'>snippet source</a> | <a href='#snippet-SchemaInclude' title='Start of snippet'>anchor</a></sup>
 <!-- endSnippet -->
 
 Available values:
@@ -107,10 +107,95 @@ await Verify(connection)
         _ => _ is TableViewBase ||
              _.Name == "MyTrigger");
 ```
-<sup><a href='/src/Tests/Tests.cs#L730-L738' title='Snippet source file'>snippet source</a> | <a href='#snippet-SchemaFilter' title='Start of snippet'>anchor</a></sup>
+<sup><a href='/src/Tests/Tests.cs#L778-L786' title='Snippet source file'>snippet source</a> | <a href='#snippet-SchemaFilter' title='Start of snippet'>anchor</a></sup>
 <!-- endSnippet -->
 
 
+#### Diagram
+
+The tables of a schema can instead be verified as a [Mermaid ER diagram](https://mermaid.js.org/syntax/entityRelationshipDiagram.html), using [DbToMermaid](https://github.com/SimonCropp/DbToMermaid). Requires net10.0 or higher.
+
+<!-- snippet: SqlServerSchemaAsDiagram -->
+<a id='snippet-SqlServerSchemaAsDiagram'></a>
+```cs
+await Verify(connection)
+    .SchemaAsDiagram();
+```
+<sup><a href='/src/Tests/Tests.cs#L342-L347' title='Snippet source file'>snippet source</a> | <a href='#snippet-SqlServerSchemaAsDiagram' title='Start of snippet'>anchor</a></sup>
+<!-- endSnippet -->
+
+Result: [Tests.SchemaAsDiagram.verified.md](/src/Tests/Tests.SchemaAsDiagram.verified.md)
+
+The diagram can be verified as markdown, svg, png, or any combination. One file is verified for each format.
+
+<!-- snippet: SqlServerSchemaAsDiagramFormats -->
+<a id='snippet-SqlServerSchemaAsDiagramFormats'></a>
+```cs
+await Verify(connection)
+    .SchemaAsDiagram(
+        DiagramFormat.Markdown |
+        DiagramFormat.Svg |
+        DiagramFormat.Png);
+```
+<sup><a href='/src/Tests/Tests.cs#L356-L364' title='Snippet source file'>snippet source</a> | <a href='#snippet-SqlServerSchemaAsDiagramFormats' title='Start of snippet'>anchor</a></sup>
+<!-- endSnippet -->
+
+Result:
+
+ * [Tests.SchemaAsDiagramFormats.verified.md](/src/Tests/Tests.SchemaAsDiagramFormats.verified.md)
+ * [Tests.SchemaAsDiagramFormats.verified.svg](/src/Tests/Tests.SchemaAsDiagramFormats.verified.svg)
+ * [Tests.SchemaAsDiagramFormats.verified.png](/src/Tests/Tests.SchemaAsDiagramFormats.verified.png)
+
+<img src="/src/Tests/Tests.SchemaAsDiagramFormats.verified.png" alt="Tests.SchemaAsDiagramFormats.verified.png">
+
+Available values:
+
+<!-- snippet: DiagramFormat.cs -->
+<a id='snippet-DiagramFormat.cs'></a>
+```cs
+namespace VerifyTests.SqlServer;
+
+/// <summary>
+/// The files produced when a schema is verified as a diagram. Can be combined.
+/// </summary>
+[Flags]
+public enum DiagramFormat
+{
+    /// <summary>
+    /// A Mermaid ER diagram in a markdown code block. Uses the `md` extension.
+    /// </summary>
+    Markdown = 1,
+
+    /// <summary>
+    /// The diagram rendered to an image. Uses the `svg` extension.
+    /// </summary>
+    Svg = 2,
+
+    /// <summary>
+    /// The diagram rendered to an image. Uses the `png` extension.
+    /// </summary>
+    Png = 4,
+
+    All = Markdown | Svg | Png
+}
+```
+<sup><a href='/src/Verify.SqlServer/SchemaValidation/DiagramFormat.cs#L1-L25' title='Snippet source file'>snippet source</a> | <a href='#snippet-DiagramFormat.cs' title='Start of snippet'>anchor</a></sup>
+<!-- endSnippet -->
+
+`SchemaIncludes` and `SchemaFilter` do not apply to a diagram. All tables are included.
+
+A rendered png may not be pixel identical across machines, so compare using [ssim](https://github.com/VerifyTests/Verify/blob/main/docs/comparer.md):
+
+<!-- snippet: UseSsimForPng -->
+<a id='snippet-UseSsimForPng'></a>
+```cs
+VerifierSettings.UseSsimForPng();
+```
+<sup><a href='/src/Tests/ModuleInit.cs#L14-L18' title='Snippet source file'>snippet source</a> | <a href='#snippet-UseSsimForPng' title='Start of snippet'>anchor</a></sup>
+<!-- endSnippet -->
+
+The svg and png are rendered by [Naiad](https://github.com/Papyrine/Naiad). Its build check requires a sponsorship, or exemption, property to be set in the consuming project. The build error lists the options.
+
 
 ### Recording
 
@@ -129,7 +214,7 @@ command.CommandText = "select Value from MyTable";
 var value = await command.ExecuteScalarAsync();
 await Verify(value!);
 ```
-<sup><a href='/src/Tests/Tests.cs#L514-L524' title='Snippet source file'>snippet source</a> | <a href='#snippet-Recording' title='Start of snippet'>anchor</a></sup>
+<sup><a href='/src/Tests/Tests.cs#L562-L572' title='Snippet source file'>snippet source</a> | <a href='#snippet-Recording' title='Start of snippet'>anchor</a></sup>
 <!-- endSnippet -->
 
 Will result in the following verified file:
@@ -184,7 +269,7 @@ await Verify(
         sqlEntries = entries
     });
 ```
-<sup><a href='/src/Tests/Tests.cs#L591-L621' title='Snippet source file'>snippet source</a> | <a href='#snippet-RecordingSpecific' title='Start of snippet'>anchor</a></sup>
+<sup><a href='/src/Tests/Tests.cs#L639-L669' title='Snippet source file'>snippet source</a> | <a href='#snippet-RecordingSpecific' title='Start of snippet'>anchor</a></sup>
 <!-- endSnippet -->
 
 
@@ -212,7 +297,7 @@ var sqlErrorsViaType = entries
     .Select(_ => _.Data)
     .OfType<ErrorEntry>();
 ```
-<sup><a href='/src/Tests/Tests.cs#L647-L666' title='Snippet source file'>snippet source</a> | <a href='#snippet-RecordingReadingResults' title='Start of snippet'>anchor</a></sup>
+<sup><a href='/src/Tests/Tests.cs#L695-L714' title='Snippet source file'>snippet source</a> | <a href='#snippet-RecordingReadingResults' title='Start of snippet'>anchor</a></sup>
 <!-- endSnippet -->
 
 

src/Directory.Build.props

@@ -2,7 +2,7 @@
 <Project>
   <PropertyGroup>
     <NoWarn>CS1591;CS0649;CS8632;NU1608;NU1109</NoWarn>
-    <Version>12.2.0</Version>
+    <Version>12.3.0</Version>
     <LangVersion>preview</LangVersion>
     <AssemblyVersion>1.0.0</AssemblyVersion>
     <PackageTags>SqlServer, Verify</PackageTags>
@@ -13,5 +13,7 @@
     <SuppressNETCoreSdkPreviewMessage>true</SuppressNETCoreSdkPreviewMessage>
     <Verify_SponsorshipExemption>OpenSource</Verify_SponsorshipExemption>
     <Verify_SponsorshipExemptionUntil>2027-08</Verify_SponsorshipExemptionUntil>
+    <Papyrine_SponsorshipExemption>OpenSource</Papyrine_SponsorshipExemption>
+    <Papyrine_SponsorshipExemptionUntil>2027-08</Papyrine_SponsorshipExemptionUntil>
   </PropertyGroup>
 </Project>

src/Directory.Packages.props

@@ -12,6 +12,7 @@
     <PackageVersion Include="Microsoft.SqlServer.SqlManagementObjects" Version="181.37.1" />
     <PackageVersion Include="ProjectDefaults" Version="1.0.184" />
     <PackageVersion Include="Sbom" Version="0.3.1" />
+    <PackageVersion Include="SqlServerToMermaid" Version="2.2.0" />
     <PackageVersion Include="TUnit" Version="1.73.5" />
     <PackageVersion Include="System.Diagnostics.DiagnosticSource" Version="10.0.12" />
     <PackageVersion Include="Verify" Version="33.3.2-beta.1" />

src/Tests/ModuleInit.cs

@@ -9,6 +9,14 @@ public static void Init() =>
     #endregion
 
     [ModuleInitializer]
-    public static void InitOther() =>
+    public static void InitOther()
+    {
+        #region UseSsimForPng
+
+        VerifierSettings.UseSsimForPng();
+
+        #endregion
+
         VerifierSettings.InitializePlugins();
+    }
 }

src/Tests/Tests.SchemaAsDiagram.verified.md

@@ -0,0 +1,78 @@
+```mermaid
+erDiagram
+  TestSchema_SchemaTable["**TestSchema_SchemaTable**"] {
+    int Id pk
+    nvarchar(50) Name
+  }
+  ChildTable["**ChildTable**"] {
+    int Id pk
+    int ParentId
+    int Value
+  }
+  ColumnTypes["**ColumnTypes**"] {
+    int Id pk
+    nvarchar(100) Name
+    nvarchar(max)(nullable) Description
+    varchar(20)(nullable) Code
+    decimal(18,4) Amount
+    bit IsActive
+    datetime2 Created
+    timestamp RowVersion
+    money(nullable) Price
+    float(nullable) Ratio
+    smallint(nullable) SmallNum
+    tinyint(nullable) TinyNum
+    bigint(nullable) BigNum
+    uniqueidentifier(nullable) UniqueCode
+    text(nullable) Notes
+    varbinary(500)(nullable) BinaryData
+    varbinary(max)(nullable) MaxBinary
+    char(10)(nullable) FixedChar
+    binary(16)(nullable) FixedBinary
+    time(nullable) TimeOnly
+    date(nullable) DateOnly
+    ntext(nullable) NText
+    xml(nullable) Xml
+  }
+  CompositeKeyTable["**CompositeKeyTable**"] {
+    int Key1 pk
+    int Key2 pk
+    nvarchar(200)(nullable) Data
+  }
+  MultiIndexTable["**MultiIndexTable**"] {
+    int Id pk
+    nvarchar(100) Name
+    nvarchar(50) Category
+    int Status
+  }
+  MultiTriggerTable["**MultiTriggerTable**"] {
+    int Id pk
+    nvarchar(100)(nullable) Name
+  }
+  MyOtherTable["**MyOtherTable**"] {
+    int(nullable) Value
+  }
+  MyTable["**MyTable**"] {
+    int(nullable) Value
+  }
+  ParentTable["**ParentTable**"] {
+    int Id pk
+    nvarchar(100) Name
+  }
+  WithComputed["**WithComputed**"] {
+    int Id pk
+    nvarchar(50) FirstName
+    nvarchar(50) LastName
+    nvarchar(101) FullName "computed"
+    int Quantity
+    decimal(10,2) UnitPrice
+    decimal(21,2)(nullable) TotalPrice "computed"
+  }
+  WithDefaults["**WithDefaults**"] {
+    int Id pk
+    varchar(20) Status
+    datetime2 Created
+    int Score
+  }
+  ParentTable ||--o{ ChildTable : "FK_ChildTable_ParentTable"
+```

src/Tests/Tests.SchemaAsDiagramFormats.verified.md

@@ -0,0 +1,78 @@
+```mermaid
+erDiagram
+  TestSchema_SchemaTable["**TestSchema_SchemaTable**"] {
+    int Id pk
+    nvarchar(50) Name
+  }
+  ChildTable["**ChildTable**"] {
+    int Id pk
+    int ParentId
+    int Value
+  }
+  ColumnTypes["**ColumnTypes**"] {
+    int Id pk
+    nvarchar(100) Name
+    nvarchar(max)(nullable) Description
+    varchar(20)(nullable) Code
+    decimal(18,4) Amount
+    bit IsActive
+    datetime2 Created
+    timestamp RowVersion
+    money(nullable) Price
+    float(nullable) Ratio
+    smallint(nullable) SmallNum
+    tinyint(nullable) TinyNum
+    bigint(nullable) BigNum
+    uniqueidentifier(nullable) UniqueCode
+    text(nullable) Notes
+    varbinary(500)(nullable) BinaryData
+    varbinary(max)(nullable) MaxBinary
+    char(10)(nullable) FixedChar
+    binary(16)(nullable) FixedBinary
+    time(nullable) TimeOnly
+    date(nullable) DateOnly
+    ntext(nullable) NText
+    xml(nullable) Xml
+  }
+  CompositeKeyTable["**CompositeKeyTable**"] {
+    int Key1 pk
+    int Key2 pk
+    nvarchar(200)(nullable) Data
+  }
+  MultiIndexTable["**MultiIndexTable**"] {
+    int Id pk
+    nvarchar(100) Name
+    nvarchar(50) Category
+    int Status
+  }
+  MultiTriggerTable["**MultiTriggerTable**"] {
+    int Id pk
+    nvarchar(100)(nullable) Name
+  }
+  MyOtherTable["**MyOtherTable**"] {
+    int(nullable) Value
+  }
+  MyTable["**MyTable**"] {
+    int(nullable) Value
+  }
+  ParentTable["**ParentTable**"] {
+    int Id pk
+    nvarchar(100) Name
+  }
+  WithComputed["**WithComputed**"] {
+    int Id pk
+    nvarchar(50) FirstName
+    nvarchar(50) LastName
+    nvarchar(101) FullName "computed"
+    int Quantity
+    decimal(10,2) UnitPrice
+    decimal(21,2)(nullable) TotalPrice "computed"
+  }
+  WithDefaults["**WithDefaults**"] {
+    int Id pk
+    varchar(20) Status
+    datetime2 Created
+    int Score
+  }
+  ParentTable ||--o{ ChildTable : "FK_ChildTable_ParentTable"
+```