test: compare the collection shadows with FSharp.Core in property tests

.github/copilot-instructions.md

@@ -29,6 +29,8 @@
 │   └── ValueCollections.fs – `Seq`, `List` and `Array` functions that return `voption` and struct tuples
 ├── tests/Cosmos.Tests/  – MSTest integration test project
 ├── tests/Cosmos.Tests.Infrastructure/ – shared test fixtures, emulator settings and assertion helpers
+├── tests/Hedgehog.MSTest/ – Hedgehog MSTest adapter for [<Property>] test methods (from hedgehogqa/fsharp-hedgehog)
+├── tests/Hedgehog.MSTest.Tests/ – the adapter's own test suite
 ├── build/               – FAKE build scripts
 └── docsSrc/             – FSharp.Formatting documentation source
 ```
@@ -40,6 +42,7 @@
 * [`FSharp.Control.Reactive`](https://github.com/fsprojects/FSharp.Reactive) – Rx extensions for F#
 * [`FsToolkit.ErrorHandling`](https://github.com/demystifyfp/FsToolkit.ErrorHandling) – `taskResult`, `Result`, `voption` CEs
 * [`Unquote`](https://github.com/SwensenSoftware/unquote) – test assertions
+* [`Hedgehog`](https://github.com/hedgehogqa/fsharp-hedgehog) – property-based testing through the `tests/Hedgehog.MSTest` adapter
 * [`MSTest`](https://github.com/microsoft/testfx) – test framework
 
 Use GitHub MCP tools for code search in these repositories when needed.
@@ -238,7 +241,9 @@ module MyTypeExtensions =
 * `COSMOS_EMULATOR_PARTITION_COUNT` is the number of partitions the emulator offers (default `25`, the Windows emulator's default `/PartitionCount`); the fixtures keep at most that many test containers at a time, one partition each.
 * `COSMOS_TEST_LEFTOVER_AGE_MINUTES` is how many minutes a `fsac-test-` database must stay unmodified before the leftover sweep of `[<AssemblyInitialize>]` and `[<AssemblyCleanup>]` deletes it (default `60`), so that the live databases of another test process on the same emulator are kept; `0` deletes every test database and is safe only while no other test process uses the emulator.
 * `COSMOS_REWRITE_BASELINES` set to `1` or `true` makes a test that compares SQL with its golden baseline (`Baseline.assertMatches`, files under `Baselines/<suite>/` of the test project) write what it produced into the baseline instead of comparing; the test then reports itself inconclusive, the rewritten files are reviewed in the diff, and CI refuses to rewrite.
-* Every test project under `tests/` references `tests/Cosmos.Tests.Infrastructure` through `tests/Directory.Build.props`; a new test project gets it without a `ProjectReference` of its own.
+* Every test project under `tests/` references `tests/Cosmos.Tests.Infrastructure` through `tests/Directory.Build.props`; a new test project gets it without a `ProjectReference` of its own. The Hedgehog MSTest adapter and its suite are the exception: they stay free of the Cosmos projects, and the suite references the adapter alone.
+* Property tests are methods of `[<TestClass>]` types marked `[<Property>]` (from `tests/Hedgehog.MSTest`), whose parameters Hedgehog generates; never call `Property.check` inside a `[<TestMethod>]`. A test project with property tests references the adapter project and the `Hedgehog` package, as `tests/Cosmos.Tests` does. A property is an instance method that returns `unit`, `Task` or `ValueTask` and fails by throwing: MSTest 4 rejects static methods and other return types, and one such method fails the discovery of the whole assembly, which `--list-tests` shows before a run. MSTest creates the test class and runs `[<TestInitialize>]` and `[<TestCleanup>]` for every generated case and every shrink step. A failed property reports a `[<Recheck("…")>]` to add next to its `Property` attribute, which then replays the counterexample. A parameter of type `DateOnly` or `TimeOnly`, or of a type that holds one, is generated like any other, and `[<DateOnly>]` and `[<TimeOnly>]` bound its value: Hedgehog 2.0.4 has no generator of the two types, so the adapter registers the ones that [hedgehogqa/fsharp-hedgehog#488](https://github.com/hedgehogqa/fsharp-hedgehog/pull/488) adds to Hedgehog, until a release has them. `Gen.auto` outside a property does not know the two types before that release.
+* `tests/Hedgehog.MSTest` and `tests/Hedgehog.MSTest.Tests` are ported from hedgehogqa/fsharp-hedgehog and proposed there too ([hedgehogqa/fsharp-hedgehog#487](https://github.com/hedgehogqa/fsharp-hedgehog/pull/487)). Their code follows the rules of this file, formatting with Fantomas and nullness checking included; the copy in the upstream pull request keeps upstream's style, so a change of behaviour goes into both. Copied files keep their Apache-2.0 header, which records every change made to them, and `THIRD-PARTY-NOTICES.md` lists them.
 * `CollectionAssert` cannot work with F# lists – use F# array syntax (`[| ... |]`) instead.
 * `StringAssert` has overloads with `StringComparison`.
 * Use `Assert.Contains` instead of `Assert.IsTrue (str.Contains ..., "message")`, and do not put the actual value into the message.

Directory.Packages.props

@@ -24,6 +24,7 @@
     <PackageVersion Include="Fake.DotNet.Paket" Version="6.2.0" />
     <PackageVersion Include="Fake.IO.FileSystem" Version="6.2.0" />
     <PackageVersion Include="Fake.Tools.Git" Version="6.2.0" />
+    <PackageVersion Include="Hedgehog" Version="2.0.4" />
     <PackageVersion Include="Microsoft.NET.Test.Sdk" Version="18.5.1" />
     <PackageVersion Include="Microsoft.SourceLink.GitHub" Version="10.0.401" />
     <PackageVersion Include="MSTest" Version="4.2.3" />

FSharp.Azure.Cosmos.slnf

@@ -4,7 +4,9 @@
     "projects": [
       "src\\Cosmos\\FSharp.Azure.Cosmos.fsproj",
       "tests\\Cosmos.Tests.Infrastructure\\FSharp.Azure.Cosmos.Tests.Infrastructure.fsproj",
-      "tests\\Cosmos.Tests\\FSharp.Azure.Cosmos.Tests.fsproj"
+      "tests\\Cosmos.Tests\\FSharp.Azure.Cosmos.Tests.fsproj",
+      "tests\\Hedgehog.MSTest\\Hedgehog.MSTest.fsproj",
+      "tests\\Hedgehog.MSTest.Tests\\Hedgehog.MSTest.Tests.fsproj"
     ]
   }
 }

FSharp.Azure.Cosmos.slnx

@@ -8,9 +8,12 @@
     <File Path="Directory.Packages.props" />
     <File Path="global.json" />
     <File Path="README.md" />
+    <File Path="THIRD-PARTY-NOTICES.md" />
   </Folder>
   <Project Path="build/build.fsproj" />
   <Project Path="src/Cosmos/FSharp.Azure.Cosmos.fsproj" />
   <Project Path="tests/Cosmos.Tests.Infrastructure/FSharp.Azure.Cosmos.Tests.Infrastructure.fsproj" />
   <Project Path="tests/Cosmos.Tests/FSharp.Azure.Cosmos.Tests.fsproj" />
+  <Project Path="tests/Hedgehog.MSTest/Hedgehog.MSTest.fsproj" />
+  <Project Path="tests/Hedgehog.MSTest.Tests/Hedgehog.MSTest.Tests.fsproj" />
 </Solution>

THIRD-PARTY-NOTICES.md

@@ -0,0 +1,35 @@
+# Third-party notices
+
+This repository contains code copied from the projects below. Each copied file names its origin and the changes made
+to it in a header comment. The rest of the repository is covered by [LICENSE](LICENSE).
+
+## fsharp-hedgehog
+
+* Source: <https://github.com/hedgehogqa/fsharp-hedgehog>, release commit
+  [`a46977278db9a60542e3df3fe0fcd74b90f38ee3`](https://github.com/hedgehogqa/fsharp-hedgehog/tree/a46977278db9a60542e3df3fe0fcd74b90f38ee3)
+  (Hedgehog 2.0.4; the repository has no tag for this release)
+* Copied into: `tests/Hedgehog.MSTest` (the Hedgehog MSTest adapter), from `src/Hedgehog.NUnit`: `Prelude.fs`,
+  `ReflectionHelpers.fs`, `AutoGenConfig.fs`, `IPropertyAttribute.fs`, `RecheckAttribute.fs`, `GenAttribute.fs`,
+  `GenAttribute.Prelude.fs`, `PropertyContext.fs`, `InternalLogic.fs`, `PropertiesAttribute.fs` and, adapted from
+  NUnit to MSTest, `PropertyAttribute.fs`
+* Ported into: `tests/Hedgehog.MSTest.Tests` (the adapter's suite), rewritten for MSTest, from
+  `tests/Hedgehog.Xunit.Tests.FSharp/PropertyTests.fs`, `tests/Hedgehog.NUnit.Tests.FSharp/PropertyTests.fs` and
+  `tests/Hedgehog.NUnit.Tests.FSharp/GenAttributePreludeTests.fs`: `Common.fs`, `PropertyTests.fs` and
+  `GenAttributePreludeTests.fs`
+* License: Apache License, Version 2.0
+
+```text
+Copyright (c) 2016 Jacob Stanley, Nikos Baxevanis
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+```

build/build.fs

@@ -354,32 +354,46 @@ let fsharpAnalyzers _ =
         dotnet.fsharpAnalyzer id args
     )
 
-let dotnetTest ctx =
-    // Create test results directory if it doesn't exist
-    Directory.create testResultsDir
-
+/// <summary>
+/// Runs <c>dotnet test</c> with the Microsoft.Testing.Platform runner for every test application, without building, in
+/// the configuration of the executing targets and with the options that <paramref name="configure"/> changes.
+/// </summary>
+let dotnetTestApplications ctx (configure : DotNet.MTPTestOptions -> DotNet.MTPTestOptions) =
     let dotnetConfiguration = configuration (ctx.Context.AllExecutingTargets)
 
     !!testsGlob
     |> Seq.iter (fun testProject ->
         DotNet.testMTP
-            (fun options -> {
-                options with
-                    NoBuild = true
-                    Configuration = Some dotnetConfiguration
-                    ResultsDirectory = if enableCodeCoverage then Some testResultsDir else None
-                    CodeCoverage =
-                        if enableCodeCoverage then
-                            Some {
-                                DotNet.MTPCodeCoverageOptions.Create () with
-                                    OutputFormat = Some DotNet.MTPCoverageFormat.Cobertura
-                            }
-                        else
-                            None
-            })
+            (fun options -> configure { options with NoBuild = true; Configuration = Some dotnetConfiguration })
             (DotNet.MTPTestTarget.Project testProject)
     )
 
+let dotnetTest ctx =
+    // Create test results directory if it doesn't exist
+    Directory.create testResultsDir
+
+    dotnetTestApplications
+        ctx
+        (fun options -> {
+            options with
+                ResultsDirectory = if enableCodeCoverage then Some testResultsDir else None
+                CodeCoverage =
+                    if enableCodeCoverage then
+                        Some {
+                            DotNet.MTPCodeCoverageOptions.Create () with
+                                OutputFormat = Some DotNet.MTPCoverageFormat.Cobertura
+                        }
+                    else
+                        None
+        })
+
+/// <summary>
+/// Lists the tests of every test application without running them. MSTest 4 fails the discovery of a whole assembly
+/// when one test method has a signature that it cannot run, such as a property method that returns a value, and the F#
+/// build gives no warning for it; listing reports that before the run, which needs the emulator, starts.
+/// </summary>
+let dotnetListTests ctx = dotnetTestApplications ctx (fun options -> { options with ListTests = true })
+
 let generateCoverageReport _ =
 
     let coverageFiles =
@@ -393,8 +407,8 @@ let generateCoverageReport _ =
         sprintf "-targetdir:\"%s\"" coverageReportDir
         // Add source dir
         sprintf "-sourcedirs:\"%s\"" sourceDirs
-        // Ignore test assemblies and the helper libraries they share
-        sprintf "-assemblyfilters:\"%s\"" "-*.Tests;-*.Tests.Infrastructure"
+        // Ignore test assemblies, the helper libraries they share, the Hedgehog MSTest adapter and Hedgehog itself
+        sprintf "-assemblyfilters:\"%s\"" "-*.Tests;-*.Tests.Infrastructure;-Hedgehog;-Hedgehog.MSTest"
         // Generate HTML and Cobertura reports
         sprintf "-reporttypes:%s" "Html;Cobertura"
     ]
@@ -640,6 +654,7 @@ let initTargets (ctx : Context.FakeExecutionContext) =
     Target.createFinal "DeleteChangelogBackupFile" deleteChangelogBackupFile // Do NOT put this in the dependency chain
     Target.create "DotnetBuild" dotnetBuild
     Target.create "FSharpAnalyzers" fsharpAnalyzers
+    Target.create "DotnetListTests" dotnetListTests
     Target.create "DotnetTest" dotnetTest
     Target.create "GenerateCoverageReport" generateCoverageReport
     Target.create "ShowCoverageReport" showCoverageReport
@@ -701,6 +716,7 @@ let initTargets (ctx : Context.FakeExecutionContext) =
 
     "DotnetRestore" =?> ("CheckFormatCode", isCI.Value)
     ==> "DotnetBuild"
+    ==> "DotnetListTests"
     ==> "DotnetTest"
     ==> "DotnetPack"
     ==> "PublishToNuGet"
@@ -711,6 +727,7 @@ let initTargets (ctx : Context.FakeExecutionContext) =
     =?> ("CheckFormatCode", isCI.Value)
     =?> ("GenerateAssemblyInfo", isPublishToGitHub)
     ==> "DotnetBuild"
+    ==> "DotnetListTests"
     ==> "DotnetTest"
     ==> "DotnetPack"
     ==>! "PublishToGitHub"

tests/Cosmos.Tests/FSharp.Azure.Cosmos.Tests.fsproj

@@ -42,6 +42,7 @@
   </ItemGroup>
 
   <ItemGroup>
+    <PackageReference Include="Hedgehog" />
     <!-- Referenced directly although the library references it too: the probe tests use IcedTasks themselves and gate which of its builders library code may use, so they must not depend on what the library happens to reference. -->
     <PackageReference Include="IcedTasks" />
     <PackageReference Include="MSTest" />
@@ -50,6 +51,8 @@
 
   <ItemGroup>
     <ProjectReference Include="..\..\src\Cosmos\FSharp.Azure.Cosmos.fsproj" />
+    <!-- The Hedgehog MSTest adapter: the [<Property>] attribute that marks the property tests of this project. -->
+    <ProjectReference Include="..\Hedgehog.MSTest\Hedgehog.MSTest.fsproj" />
   </ItemGroup>
 
 </Project>