Align VersionVariablesJsonModel to git version variables

Fix cache tests
Update documentation

Author: phatcher

docs/input/docs/reference/configuration.md

@@ -591,6 +591,13 @@ details on the syntax. Default set to `Enabled`; set to `Disabled` to disable.
 
 Sets the format which will be used to format the `CommitDate` output variable.
 
+### custom-version-format
+
+Specifies the format of `CustomVersion`, allowing for a user-specific output variable
+that can be used, for example, as the NuGet package vesion.
+Default set to `{SemVer}`. 
+Follows the same formatting semantics as `assembly-file-versioning-format`.
+
 ### ignore
 
 The header property for the `ignore` configuration.

src/GitVersion.Core.Tests/Core/GitVersionExecutorTests.cs

@@ -117,6 +117,7 @@ public void CacheFileExistsOnDisk()
           "AssemblySemVer": "4.10.3.0",
           "AssemblySemFileVer": "4.10.3.0",
           "FullSemVer": "4.10.3-test.19",
+          "CustomVersion": "4.10.3.0",
           "InformationalVersion": "4.10.3-test.19+Branch.feature/test.Sha.dd2a29aff0c948e1bdf3dabbe13e1576e70d5f9f",
           "BranchName": "feature/test",
           "EscapedBranchName": "feature-test",
@@ -180,6 +181,7 @@ public void CacheFileExistsOnDiskWhenOverrideConfigIsSpecifiedVersionShouldBeDyn
           "AssemblySemVer": "4.10.3.0",
           "AssemblySemFileVer": "4.10.3.0",
           "FullSemVer": "4.10.3-test.19",
+          "CustomVersion": "4.10.3.0",
           "InformationalVersion": "4.10.3-test.19+Branch.feature/test.Sha.dd2a29aff0c948e1bdf3dabbe13e1576e70d5f9f",
           "BranchName": "feature/test",
           "EscapedBranchName": "feature-test",
@@ -271,6 +273,7 @@ public void ConfigChangeInvalidatesCache(string configFileName)
           "AssemblySemVer": "4.10.3.0",
           "AssemblySemFileVer": "4.10.3.0",
           "FullSemVer": "4.10.3-test.19",
+          "CustomVersion": "4.10.3.0",
           "InformationalVersion": "4.10.3-test.19+Branch.feature/test.Sha.dd2a29aff0c948e1bdf3dabbe13e1576e70d5f9f",
           "BranchName": "feature/test",
           "EscapedBranchName": "feature-test",
@@ -333,6 +336,7 @@ public void NoCacheBypassesCache()
           "AssemblySemVer": "4.10.3.0",
           "AssemblySemFileVer": "4.10.3.0",
           "FullSemVer": "4.10.3-test.19",
+          "CustomVersion": "4.10.3.0",
           "InformationalVersion": "4.10.3-test.19+Branch.feature/test.Sha.dd2a29aff0c948e1bdf3dabbe13e1576e70d5f9f",
           "BranchName": "feature/test",
           "EscapedBranchName": "feature-test",

src/GitVersion.Output/Serializer/VersionVariablesJsonModel.cs

@@ -34,6 +34,9 @@ internal class VersionVariablesJsonModel
     [JsonPropertyDescription("Suitable for .NET AssemblyInformationalVersion. Defaults to FullSemVer suffixed by FullBuildMetaData.")]
     public string? InformationalVersion { get; set; }
 
+    [JsonPropertyDescription("A custom version, suitable for package managers, e.g. NuGet, with appropriate formatting. Defaults to SemVer.")]
+    public string? CustomVersion { get; set; }
+
     [JsonPropertyDescription("The major version. Should be incremented on breaking changes.")]
     public int? Major { get; set; }