ProjNET v3: modernized engine with expanded projection/transformation coverage and a built-in EPSG catalog

.editorconfig

@@ -9,4 +9,31 @@ dotnet_style_predefined_type_for_locals_parameters_members = true:error
 dotnet_style_predefined_type_for_member_access = true:error
 csharp_style_var_for_built_in_types = false:error
 csharp_style_var_when_type_is_apparent = true:error
-csharp_style_var_elsewhere = true:error
+csharp_style_var_elsewhere = false:error
+csharp_using_directive_placement = inside_namespace:error
+csharp_style_namespace_declarations = file_scoped:error
+dotnet_diagnostic.IDE0041.severity = error
+
+dotnet_style_qualification_for_event = true:error
+dotnet_style_qualification_for_field = true:error
+dotnet_style_qualification_for_method = true:error
+dotnet_style_qualification_for_property = true:error
+dotnet_diagnostic.SA1633.severity = none
+dotnet_diagnostic.SA1634.severity = none
+dotnet_diagnostic.SA1635.severity = none
+dotnet_diagnostic.SA1636.severity = none
+dotnet_diagnostic.SA1637.severity = none
+dotnet_diagnostic.SA1638.severity = none
+
+[{test/ProjNet.Tests/*.cs,test/ProjNet.Tests/**/*.cs}]
+dotnet_diagnostic.SA1611.severity = none
+dotnet_diagnostic.CA1707.severity = none
+dotnet_diagnostic.CS1591.severity = none
+
+[src/ProjNet/CoordinateSystems/Projections/AiroceanProjection.cs]
+dotnet_diagnostic.SA1117.severity = none
+dotnet_diagnostic.SA1201.severity = none
+
+[{src/ProjNet.Benchmark/*.cs,src/ProjNet.Benchmark/**/*.cs}]
+dotnet_diagnostic.CA1822.severity = none
+dotnet_diagnostic.CS1591.severity = none

.gitattributes

@@ -1,2 +1,27 @@
+# Auto-detect text files and normalize line endings
 * text=auto
-*.cs text=auto diff=csharp
+
+# Source code
+*.cs text diff=csharp
+*.csproj text diff=xml
+*.props text diff=xml
+*.targets text diff=xml
+*.sln text eol=crlf
+
+# Generated catalog — collapse in GitHub PRs
+*.g.cs linguist-generated=true
+
+# Scripts and config
+*.py text diff=python
+*.ps1 text
+*.json text
+*.xml text diff=xml
+*.md text diff=markdown
+*.txt text
+*.yml text
+*.yaml text
+*.editorconfig text
+
+# Archives
+*.zip binary
+*.nupkg binary

.github/copilot-instructions.md

@@ -0,0 +1,14 @@
+# Copilot instructions
+
+## Repository context
+
+- Build and test from the repository root.
+- Build with `dotnet build .\ProjNet4GeoAPI.sln -c Release --tl:off -v minimal`.
+- Test with `dotnet test --project .\test\ProjNet.Tests\ProjNET.Tests.csproj`.
+- The main CI workflow is `.github/workflows/full-ci.yml`; benchmark monitoring lives in `.github/workflows/benchmarks.yml`; CodeQL uses `.github/workflows/codeql.yml`; mutation testing uses `.github/workflows/mutation-tests.yml`.
+- Coverage generation mirrors CI after a Release build: run `dotnet tool restore`, then `dotnet build .\ProjNet4GeoAPI.sln -c Release --tl:off -v minimal`, then `dotnet dotnet-coverage collect --output .\coverage-out\coverage.cobertura.xml --output-format cobertura -- dotnet test --project .\test\ProjNet.Tests\ProjNET.Tests.csproj -c Release --no-build`.
+- Curated benchmark runs mirror CI after a Release build: use `.\.github\scripts\Invoke-CuratedBenchmarks.ps1 -Mode Smoke -NoBuild` or `.\.github\scripts\Invoke-CuratedBenchmarks.ps1 -Mode Full -NoBuild`; keep `Get-CuratedBenchmarkConfiguration.ps1` as the single source of truth and validate converted datasets with `Convert-BenchmarkReports.ps1` plus `Assert-CuratedBenchmarkDataset.ps1`.
+- The library ships `netstandard2.0`, `netstandard2.1`, and `net8.0`.
+- Public API changes must update `src/ProjNet/PublicAPI.Shipped.txt` intentionally.
+- In touched C# code, prefer `is null` / `is not null` checks and avoid broad warning suppressions.
+

.github/dependabot.yml

@@ -0,0 +1,26 @@
+version: 2
+
+updates:
+  - package-ecosystem: nuget
+    directory: /
+    schedule:
+      interval: weekly
+    labels:
+      - dependencies
+      - nuget
+    commit-message:
+      prefix: 'deps(nuget):'
+      include: scope
+    ignore:
+      - dependency-name: StyleCop.Analyzers
+
+  - package-ecosystem: github-actions
+    directory: /
+    schedule:
+      interval: weekly
+    labels:
+      - dependencies
+      - github-actions
+    commit-message:
+      prefix: 'deps(actions):'
+      include: scope

.github/instructions/csharp.instructions.md

@@ -0,0 +1,14 @@
+# C# specific copilot instructions
+
+## Mandatory quality gates
+
+### Code analysis and code style
+
+- Null checks must use pattern syntax: use `is null` and `is not null` instead of `== null` and `!= null`.
+
+### Code Warnings and StyleCop warnings
+
+- StyleCop warnings are blocking: fix them before task completion.
+- Keep exceptions narrow and only for clearly generated code (for example `*.g.cs` files or files with a standard `<auto-generated>` header).
+- Do not add broad suppressions (global, project-wide, or blanket pragmas). Any suppression change must be explicitly approved and scoped to a specific diagnostic.
+- Any suppression must be accompanied by a justification comment that explains why the suppression is necessary and what the intended fix is (if applicable). The justification should be clear and concise, providing enough context for reviewers to understand the reasoning behind the suppression.

.github/problem-matchers/dotnet.json

@@ -0,0 +1,18 @@
+{
+  "problemMatcher": [
+    {
+      "owner": "dotnet-msbuild",
+      "pattern": [
+        {
+          "regexp": "^(.*)\\((\\d+),(\\d+)\\):\\s+(warning|error)(?:\\s+([A-Za-z]+\\d+))?:\\s+(.*?)(?:\\s+\\[(.*)\\])?$",
+          "file": 1,
+          "line": 2,
+          "column": 3,
+          "severity": 4,
+          "code": 5,
+          "message": 6
+        }
+      ]
+    }
+  ]
+}

.github/scripts/Assert-CuratedBenchmarkDataset.ps1

@@ -0,0 +1,72 @@
+[CmdletBinding()]
+param(
+    [Parameter(Mandatory = $true)]
+    [string]$DatasetPath
+)
+
+. "$PSScriptRoot/Get-CuratedBenchmarkConfiguration.ps1"
+
+$doubleStyles = [System.Globalization.NumberStyles]::Float -bor [System.Globalization.NumberStyles]::AllowThousands
+$culture = [System.Globalization.CultureInfo]::InvariantCulture
+
+[object[]]$entries = Get-Content -Path $DatasetPath -Raw | ConvertFrom-Json
+$entryNames = @($entries | ForEach-Object { $_.name } | Sort-Object)
+$configuration = Get-CuratedBenchmarkConfiguration
+$expectedNames = @($configuration.RequiredDatasetPatterns | Sort-Object)
+
+if ($entryNames.Count -ne $expectedNames.Count)
+{
+    throw "Curated benchmark dataset contains $($entryNames.Count) entries but expected $($expectedNames.Count)."
+}
+
+$missingEntries = $expectedNames | Where-Object { $_ -notin $entryNames }
+if ($missingEntries.Count -gt 0)
+{
+    throw "Curated benchmark dataset is missing expected entries: $($missingEntries -join ', ')."
+}
+
+$unexpectedEntries = $entryNames | Where-Object { $_ -notin $expectedNames }
+if ($unexpectedEntries.Count -gt 0)
+{
+    throw "Curated benchmark dataset contains unexpected entries: $($unexpectedEntries -join ', ')."
+}
+
+foreach ($entry in $entries)
+{
+    if ([string]::IsNullOrWhiteSpace($entry.name))
+    {
+        throw 'Curated benchmark dataset contains an entry without a valid name.'
+    }
+
+    if ($entry.unit -ne 'ns')
+    {
+        throw "Curated benchmark dataset entry '$($entry.name)' does not use the expected 'ns' unit."
+    }
+
+    $value = 0d
+    if ($null -eq $entry.value -or -not [double]::TryParse([string]$entry.value, $doubleStyles, $culture, [ref]$value))
+    {
+        throw "Curated benchmark dataset entry '$($entry.name)' does not contain a valid numeric value."
+    }
+
+    if ([double]::IsNaN($value) -or [double]::IsInfinity($value) -or $value -lt 0)
+    {
+        throw "Curated benchmark dataset entry '$($entry.name)' does not contain a finite non-negative numeric value."
+    }
+
+    $range = 0d
+    if ($null -eq $entry.range -or -not [double]::TryParse([string]$entry.range, $doubleStyles, $culture, [ref]$range))
+    {
+        throw "Curated benchmark dataset entry '$($entry.name)' does not contain a valid numeric range."
+    }
+
+    if ([double]::IsNaN($range) -or [double]::IsInfinity($range) -or $range -lt 0)
+    {
+        throw "Curated benchmark dataset entry '$($entry.name)' does not contain a finite non-negative numeric range."
+    }
+
+    if ($entry.extra -isnot [string] -or [string]::IsNullOrWhiteSpace($entry.extra))
+    {
+        throw "Curated benchmark dataset entry '$($entry.name)' does not contain explanatory extra metadata."
+    }
+}

.github/scripts/Convert-BenchmarkReports.ps1

@@ -0,0 +1,63 @@
+param(
+    [Parameter(Mandatory = $true)]
+    [string]$InputDirectory,
+
+    [Parameter(Mandatory = $true)]
+    [string]$OutputFile
+)
+
+$reportFiles = Get-ChildItem -Path $InputDirectory -Filter '*-report-full-compressed.json' -File | Sort-Object Name
+if ($reportFiles.Count -eq 0)
+{
+    throw "No BenchmarkDotNet JSON reports were found in '$InputDirectory'."
+}
+
+$entries = foreach ($reportFile in $reportFiles)
+{
+    $report = Get-Content -Path $reportFile.FullName -Raw | ConvertFrom-Json
+    foreach ($benchmark in @($report.Benchmarks))
+    {
+        if ($null -eq $benchmark.Statistics)
+        {
+            throw "Benchmark '$($benchmark.FullName)' did not produce statistics."
+        }
+
+        $allocatedMetric = @($benchmark.Metrics) |
+            Where-Object { $_.Descriptor.Id -eq 'Allocated Memory' } |
+            Select-Object -First 1
+
+        $extraLines = @(
+            "Type: $($benchmark.Type)",
+            "Runtime: $($report.HostEnvironmentInfo.RuntimeVersion)",
+            "Mean: $([double]$benchmark.Statistics.Mean) ns",
+            "StdDev: $([double]$benchmark.Statistics.StandardDeviation) ns"
+        )
+
+        if ($null -ne $allocatedMetric)
+        {
+            $extraLines += "Allocated: $([double]$allocatedMetric.Value) B/op"
+        }
+
+        [pscustomobject]@{
+            name = $benchmark.FullName
+            unit = 'ns'
+            value = [double]$benchmark.Statistics.Mean
+            range = [string]([math]::Round([double]$benchmark.Statistics.StandardDeviation, 4))
+            extra = $extraLines -join [Environment]::NewLine
+        }
+    }
+}
+
+$outputDirectory = Split-Path -Parent $OutputFile
+if (-not [string]::IsNullOrWhiteSpace($outputDirectory) -and -not (Test-Path $outputDirectory))
+{
+    New-Item -ItemType Directory -Path $outputDirectory -Force | Out-Null
+}
+
+$sortedEntries = @($entries | Sort-Object name)
+
+$sortedEntries |
+    ConvertTo-Json -Depth 5 -AsArray |
+    Set-Content -Path $OutputFile -Encoding utf8NoBOM
+
+Write-Host "Wrote $($sortedEntries.Count) benchmark entries to '$OutputFile'."

.github/scripts/Get-CuratedBenchmarkConfiguration.ps1

@@ -0,0 +1,74 @@
+function Get-CuratedBenchmarkConfiguration
+{
+    $catalogFirstBenchmarks = @(
+        'ProjNet.Benchmark.CatalogFirstTransformationLookupBenchmarks.FirstCreateTransformation4326To3857'
+    )
+
+    $wktParsingBenchmarks = @(
+        'ProjNet.Benchmark.WktParsingBenchmarks.ParseSimpleGeographicCs',
+        'ProjNet.Benchmark.WktParsingBenchmarks.ParseProjectedCs',
+        'ProjNet.Benchmark.WktParsingBenchmarks.ParseCompoundCs',
+        'ProjNet.Benchmark.WktParsingBenchmarks.ParseGeodeticWkt2',
+        'ProjNet.Benchmark.WktParsingBenchmarks.ParseProjectedWkt2',
+        'ProjNet.Benchmark.WktParsingBenchmarks.ParseBoundWkt2'
+    )
+
+    $projectionTransformBenchmarks = @(
+        'ProjNet.Benchmark.ProjectionTransformBenchmarks.TransformBatchMercator',
+        'ProjNet.Benchmark.ProjectionTransformBenchmarks.TransformBatchUtm32N',
+        'ProjNet.Benchmark.ProjectionTransformBenchmarks.TransformBatchLambert93'
+    )
+
+    $projParityBenchmarks = @(
+        'ProjNet.Benchmark.ProjParityBenchmarks.Wgs84ToWebMercatorBatched(PointCount: 10000)',
+        'ProjNet.Benchmark.ProjParityBenchmarks.Wgs84ToWebMercatorOneByOne(PointCount: 10000)',
+        'ProjNet.Benchmark.ProjParityBenchmarks.Wgs84ToUtm32NBatched(PointCount: 10000)',
+        'ProjNet.Benchmark.ProjParityBenchmarks.Wgs84ToUtm31NBatched(PointCount: 10000)',
+        'ProjNet.Benchmark.ProjParityBenchmarks.Utm31NToWgs84Batched(PointCount: 10000)',
+        'ProjNet.Benchmark.ProjParityBenchmarks.Wgs84ToLambert93Batched(PointCount: 10000)',
+        'ProjNet.Benchmark.ProjParityBenchmarks.Lambert93ToWgs84Batched(PointCount: 10000)',
+        'ProjNet.Benchmark.ProjParityBenchmarks.WebMercatorToWgs84Batched(PointCount: 10000)',
+        'ProjNet.Benchmark.ProjParityBenchmarks.Wgs84ToWebMercatorBatchedWithNoise(PointCount: 10000)'
+    )
+
+    $transformationFactoryBenchmarks = @(
+        'ProjNet.Benchmark.TransformationFactoryBenchmarks.CreateTransformWgs84ToMercator',
+        'ProjNet.Benchmark.TransformationFactoryBenchmarks.CreateTransformWgs84ToUtm32N',
+        'ProjNet.Benchmark.TransformationFactoryBenchmarks.CreateTransformUtm32NToLambert93'
+    )
+
+    $allCuratedBenchmarks =
+        $catalogFirstBenchmarks +
+        $wktParsingBenchmarks +
+        $projectionTransformBenchmarks +
+        $projParityBenchmarks +
+        $transformationFactoryBenchmarks
+
+    return @{
+        FullRuns = @(
+            @{
+                Filters = $catalogFirstBenchmarks + $wktParsingBenchmarks
+                Overrides = @()
+            },
+            @{
+                Filters = $projectionTransformBenchmarks + $projParityBenchmarks + $transformationFactoryBenchmarks
+                Overrides = @('--launchCount', '1', '--warmupCount', '1', '--iterationCount', '3')
+            }
+        )
+        SmokeRuns = @(
+            @{
+                Filters = $catalogFirstBenchmarks
+                Overrides = @('--launchCount', '1', '--warmupCount', '0', '--iterationCount', '1')
+            },
+            @{
+                Filters = $wktParsingBenchmarks
+                Overrides = @('--launchCount', '1', '--warmupCount', '1', '--iterationCount', '1')
+            },
+            @{
+                Filters = $projectionTransformBenchmarks + $projParityBenchmarks + $transformationFactoryBenchmarks
+                Overrides = @('--launchCount', '1', '--warmupCount', '1', '--iterationCount', '1')
+            }
+        )
+        RequiredDatasetPatterns = $allCuratedBenchmarks
+    }
+}