Fixes faulty LFS file check error

We need files to be restored from LFS before we can use them - otherwise they are empty!

The previous check I had could not distinguish between an empty file and file that had been modified.

I've now written a far more detailed script that should be able to handle new and modified files.

It also now skips running if it was run withing the last hour

AudioAnalysis.sln

@@ -7,6 +7,7 @@ Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "Solution Items", "Solution
 		.editorconfig = .editorconfig
 		tests\Acoustics.Test\.runsettings = tests\Acoustics.Test\.runsettings
 		src\AP.CopyFiles.targets = src\AP.CopyFiles.targets
+		src\AP.RequireLfsAssets.targets = src\AP.RequireLfsAssets.targets
 		src\AP.VersionBuild.targets = src\AP.VersionBuild.targets
 		src\AssemblyMetadata.cs.template = src\AssemblyMetadata.cs.template
 		src\AssemblyMetadata.Generated.targets = src\AssemblyMetadata.Generated.targets

src/.gitignore

@@ -1,2 +1,3 @@
 AssemblyMetadata.Generated.cs
-AssemblyMetadata.Generated.targets
+AssemblyMetadata.Generated.targets
+.lfs_check_last_check

src/AP.RequireLfsAssets.targets

@@ -4,12 +4,11 @@
 
   <!-- Register our task that as something to run before standard build target -->
   <Target Name="APRequireLfsAssets" BeforeTargets="PrepareForBuild">
-    <!-- <Message Text="[APVersionBeforeBuild] Debug: $(RuntimeIdentifier)" Importance="High" /> -->
-    <Exec Command="git lfs ls-files" ConsoleToMSBuild="True" EchoOff="false" StandardOutputImportance="low" WorkingDirectory="$(MSBuildThisFileDirectory)..">
-      <Output TaskParameter="ConsoleOutput" ItemName="FileStatus" />
+    <PropertyGroup>
+      <CheckLfsCommand>pwsh –NonInteractive -noprofile -File "$(MSBuildThisFileDirectory)lfs_check.ps1"</CheckLfsCommand>
+    </PropertyGroup>
+    <Exec Command="$(CheckLfsCommand)" EchoOff="false" StandardOutputImportance="High" WorkingDirectory="$(MSBuildThisFileDirectory)..">
     </Exec>
-    <!--<Error File="$([System.String]::new(%(FileStatus.Identity)).Substring(13).Trim())" Code="AP001" Text="Git LFS BLOB has not been restored and only contains a LFS pointer to the file." Condition="$([System.String]::new(%(FileStatus.Identity)).Contains(' - ')) And Exists('$(MSBuildThisFileDirectory)../$([System.String]::new(%(FileStatus.Identity)).Substring(13).Trim())')" ContinueOnError="ErrorAndContinue"/> -->
 
-    <!-- <Error Condition="'$(MSBuildLastTaskResult)'=='false'" Text="AP build cannot continue there are Git LFS assets that have not been restored. Please follow the instructions at https://github.com/QutEcoacoustics/audio-analysis/blob/master/CONTRIBUTING.md#AP001" /> -->
   </Target>
 </Project>

src/lfs_check.ps1

@@ -0,0 +1,48 @@
+#!/usr/bin/env pwsh
+$cache_file = "$PSScriptRoot\.lfs_check_last_check"
+if ([System.IO.File]::Exists($cache_file) -and [DateTime]::Now.Subtract([System.IO.File]::GetLastWriteTime($cache_file)).TotalSeconds -lt 3600) {
+    Write-Output "Skipping lfs check because .lfs_check_last_check exists"
+    exit 0
+}
+
+$solution_root = Resolve-Path "$PSScriptRoot/.."
+$slash = [System.IO.Path]::DirectorySeparatorChar
+
+if ($null -eq (Get-Command "git-lfs" -ErrorAction SilentlyContinue )) {
+    Write-Output "$solution_root${slash}src${slash}AP.RequireLfsAssets.targets`:git-lfs error AP0003: git-lfs must be installed and must be available on PATH."
+    exit;
+}
+
+Push-Location
+Set-Location $solution_root
+$errored = $false
+foreach($line in (git-lfs ls-files)) {
+    # format:
+    # 1da5b69f92 * tests/Fixtures/whip bird2.wav
+    $status = $line[11]
+    if ($status -eq '*') {
+        continue
+    }
+
+    if ($status -eq '-') {
+        $file = $line.SubString(13)
+        $status = git status --porcelain $file
+        $has_changed = ($null -ne $status)
+        if (-not $has_changed) {
+            Write-Output "$file`:git-lfs error AP0001: Git LFS BLOB has not been restored. The file is empty! It contains only a LFS pointer."
+            $errored = $true
+        }
+    }
+}
+
+if ($errored -eq $true) {
+    Write-Output "$solution_root${slash}src${slash}AP.RequireLfsAssets.targets`:git-lfs error AP0002: AP build cannot continue there are Git LFS assets that have not been restored. Please follow the instructions at https://github.com/QutEcoacoustics/audio-analysis/blob/master/CONTRIBUTING.md#AP001"
+}
+else  {
+    $null >> $cache_file
+}
+
+Pop-Location
+
+
+exit 0