Merge pull request #486: [EXP] Use Git with builtin FS Monitor

This also adjusts the true/false part of the CI builds to correspond to the FS Monitor builtin instead of Watchman.

Author: derrickstolee

.github/workflows/continuous-integration.yml

@@ -15,7 +15,7 @@ jobs:
       fail-fast: false
       matrix:
         os: [ubuntu-16.04, ubuntu-18.04, ubuntu-20.04, windows-2019, macos-10.15]
-        watchman: [false, true]
+        experimental: [false, true]
 
     env:
       BUILD_FRAGMENT: bin/Release/netcoreapp3.1
@@ -45,20 +45,20 @@ jobs:
       if: runner.os == 'Linux'
       run: |
         echo "BUILD_PLATFORM=${{ runner.os }}" >>$GITHUB_ENV
-        echo "TRACE2_BASENAME=Trace2.${{ github.run_id }}__${{ github.run_number }}__${{ matrix.os }}__${{ matrix.watchman }}" >>$GITHUB_ENV
+        echo "TRACE2_BASENAME=Trace2.${{ github.run_id }}__${{ github.run_number }}__${{ matrix.os }}__${{ matrix.experimental }}" >>$GITHUB_ENV
 
     - name: Setup platform (Mac)
       if: runner.os == 'macOS'
       run: |
         echo 'BUILD_PLATFORM=Mac' >>$GITHUB_ENV
-        echo "TRACE2_BASENAME=Trace2.${{ github.run_id }}__${{ github.run_number }}__${{ matrix.os }}__${{ matrix.watchman }}" >>$GITHUB_ENV
+        echo "TRACE2_BASENAME=Trace2.${{ github.run_id }}__${{ github.run_number }}__${{ matrix.os }}__${{ matrix.experimental }}" >>$GITHUB_ENV
 
     - name: Setup platform (Windows)
       if: runner.os == 'Windows'
       run: |
         echo "BUILD_PLATFORM=${{ runner.os }}" >>$env:GITHUB_ENV
         echo 'BUILD_FILE_EXT=.exe' >>$env:GITHUB_ENV
-        echo "TRACE2_BASENAME=Trace2.${{ github.run_id }}__${{ github.run_number }}__${{ matrix.os }}__${{ matrix.watchman }}" >>$env:GITHUB_ENV
+        echo "TRACE2_BASENAME=Trace2.${{ github.run_id }}__${{ github.run_number }}__${{ matrix.os }}__${{ matrix.experimental }}" >>$env:GITHUB_ENV
 
     - name: Setup Git installer
       shell: bash
@@ -98,39 +98,9 @@ jobs:
         Wait-Process $files[0].Basename
         Get-ItemProperty -Path 'Registry::HKEY_LOCAL_MACHINE\SOFTWARE\GitForWindows'
 
-    - name: Install Watchman (Linux)
-      if: runner.os == 'Linux' && matrix.watchman
-      run: |
-        cd ..
-        git clone https://github.com/facebook/watchman.git -b v4.9.0 --depth 1
-        cd watchman
-        ./autogen.sh
-        GCC_VERSION=$(gcc -dumpversion | cut -d. -f1)
-        if [ "$GCC_VERSION" -ge 7 ]; then CPPFLAGS="-Wno-error=format-truncation"; fi
-        if [ "$GCC_VERSION" -ge 8 ]; then CPPFLAGS="$CPPFLAGS -Wno-error=class-memaccess"; fi
-        export CPPFLAGS
-        ./configure --without-python
-        make
-        sudo make install
-
-    - name: Install Watchman (Mac)
-      if: runner.os == 'macOS' && matrix.watchman
-      run: brew install watchman
-
-    - name: Install Watchman (Windows)
-      if: runner.os == 'Windows' && matrix.watchman
-      run: |
-        Write-Host 'Downloading Watchman ...'
-        $Uri = (Select-Xml -Path Directory.Build.props -XPath /Project/PropertyGroup/WatchmanPackageUrl).Node.'#text'
-        Set-Location -Path ..
-        Invoke-WebRequest -Uri $Uri -OutFile watchman.zip
-        Expand-Archive watchman.zip
-        Write-Host 'Installing Watchman ...'
-        New-Item -Path 'C:\Program Files' -Name Watchman -ItemType Directory | Out-Null
-        Copy-Item -Path 'watchman\watchman-*-windows\bin\*' -Destination 'C:\Program Files\Watchman'
-        $ENV:PATH="$ENV:PATH;C:\Program Files\Watchman"
-        & watchman --version
-        echo "PATH=$ENV:PATH" >>$env:GITHUB_ENV
+    - name: Configure Experimental
+      if: matrix.experimental
+      run: git config --global feature.scalar experimental
 
     - id: functional_test
       name: Functional test
@@ -140,6 +110,7 @@ jobs:
         export GIT_TRACE2_PERF="$PWD/$TRACE2_BASENAME/Perf"
         export GIT_TRACE2_EVENT_BRIEF=true
         export GIT_TRACE2_PERF_BRIEF=true
+        export SCALAR_FUNCTIONAL_TEST_EXPERIMENTAL=${{ matrix.experimental }}
         mkdir -p "$TRACE2_BASENAME"
         mkdir -p "$TRACE2_BASENAME/Event"
         mkdir -p "$TRACE2_BASENAME/Perf"

Directory.Build.props

@@ -43,7 +43,7 @@
        VFS for Git (which is less flexible). Only update that version if we rely upon a
        new command-line interface in Git or if there is a truly broken interaction.
     -->
-    <GitPackageVersion>2.20210114.2</GitPackageVersion>
+    <GitPackageVersion>2.20210208.1-exp</GitPackageVersion>
     <MinimumGitVersion>v2.25.0.vfs.1.1</MinimumGitVersion>
 
     <WatchmanPackageUrl>https://github.com/facebook/watchman/releases/download/v2020.08.03.00/watchman-v2020.08.03.00-windows.zip</WatchmanPackageUrl>

Scalar.Common/Git/GitVersion.cs

@@ -49,7 +49,7 @@ public GitFeatureFlags GetFeatures()
                 flags |= GitFeatureFlags.MaintenanceBuiltin;
             }
 
-            if (this.Features.Contains("fsmonitor--daemon"))
+            if (this.Extra?.Equals("exp") == true)
             {
                 flags |= GitFeatureFlags.BuiltinFSMonitor;
             }

Scalar.Common/Maintenance/ConfigStep.cs

@@ -219,6 +219,16 @@ public bool TrySetConfig(out string error)
             );
             GitFeatureFlags flags = GitVersion.GetAvailableGitFeatures(this.Context.Tracer);
             config.TryParseAsString(out string scalar, out error, defaultValue: "true");
+            this.Context.Tracer.RelatedInfo($"feature.scalar={scalar}");
+
+            string envVar = Environment.GetEnvironmentVariable("SCALAR_FUNCTIONAL_TEST_EXPERIMENTAL");
+
+            if (bool.TryParse(envVar, out bool result) && result)
+            {
+                scalar = "experimental";
+            }
+
+            this.Context.Tracer.RelatedInfo($"feature.scalar={scalar}, SCALAR_FUNCTIONAL_TEST_EXPERIMENTAL={envVar}");
 
             if (StringComparer.OrdinalIgnoreCase.Equals(scalar, "false"))
             {
@@ -231,7 +241,9 @@ public bool TrySetConfig(out string error)
             }
             else if (StringComparer.OrdinalIgnoreCase.Equals(scalar, "experimental")
                      // Make sure Git supports builtin FS Monitor
-                     && flags.HasFlag(GitFeatureFlags.BuiltinFSMonitor))
+                     && flags.HasFlag(GitFeatureFlags.BuiltinFSMonitor)
+                     // but not on Linux yet
+                      && !RuntimeInformation.IsOSPlatform(OSPlatform.Linux))
             {
                 // ":internal:" is a custom value to specify the builtin
                 // FS Monitor feature.

Scalar.FunctionalTests/Tools/ScalarFunctionalTestEnlistment.cs

@@ -157,17 +157,11 @@ public string GetPackRoot(FileSystemRunner fileSystem)
 
         public void DeleteEnlistment()
         {
-            string watchmanLocation = ProcessHelper.GetProgramLocation("watchman");
-            if (!string.IsNullOrEmpty(watchmanLocation))
+            string envVar = Environment.GetEnvironmentVariable("SCALAR_FUNCTIONAL_TEST_EXPERIMENTAL");
+
+            if (bool.TryParse(envVar, out bool result) && result)
             {
-                try
-                {
-                    ProcessHelper.Run(Path.Combine(watchmanLocation, "watchman"), $"watch-del {this.RepoRoot}");
-                }
-                catch (Exception ex)
-                {
-                    Console.WriteLine($"Failed to delete watch on {this.RepoRoot}. {ex.ToString()}");
-                }
+                GitProcess.InvokeProcess(this.RepoRoot, "fsmonitor--daemon --stop");
             }
 
             TestResultsHelper.OutputScalarLogs(this);

Scalar.UnitTests/Common/GitVersionTests.cs

@@ -70,17 +70,29 @@ public void GetFeatureFlags_MaintenanceBuiltin()
         [TestCase]
         public void GetFeatureFlags_BuiltinFSMonitor()
         {
-            GitVersion version = new GitVersion(2, 30, 0, "vfs", 0, 0);
-            GitFeatureFlags gitFeatures = version.GetFeatures();
-            gitFeatures.HasFlag(GitFeatureFlags.BuiltinFSMonitor).ShouldBeFalse($"Incorrect for version {version}");
+            var notSupportedVerisons = new List<GitVersion>
+            {
+                new GitVersion(2, 31, 0),
+                new GitVersion(2, 29, 0, "windows"),
+                new GitVersion(2, 30, 0, "vfs", 0, 1),
+            };
+
+            foreach (GitVersion version in notSupportedVerisons)
+            {
+                GitFeatureFlags gitGitFeatures = version.GetFeatures();
+                gitGitFeatures.HasFlag(GitFeatureFlags.BuiltinFSMonitor).ShouldBeFalse($"Incorrect for version {version}");
+            }
 
-            version.Features.Add("bogus");
-            gitFeatures = version.GetFeatures();
-            gitFeatures.HasFlag(GitFeatureFlags.BuiltinFSMonitor).ShouldBeFalse($"Incorrect for version {version}");
+            var supportedVerisons = new List<GitVersion>
+            {
+                new GitVersion(2, 30, 0, "vfs", 0, 0, extra: "exp"),
+            };
 
-            version.Features.Add("fsmonitor--daemon");
-            gitFeatures = version.GetFeatures();
-            gitFeatures.HasFlag(GitFeatureFlags.BuiltinFSMonitor).ShouldBeTrue($"Incorrect for version {version}");
+            foreach (GitVersion version in supportedVerisons)
+            {
+                GitFeatureFlags gitGitFeatures = version.GetFeatures();
+                gitGitFeatures.HasFlag(GitFeatureFlags.BuiltinFSMonitor).ShouldBeTrue($"Incorrect for version {version}");
+            }
         }
 
         [TestCase]