add Watchman-enabled functional tests to GitHub Actions CI

.github/workflows/continuous-integration.yml

@@ -15,6 +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]
 
     env:
       BUILD_FRAGMENT: bin/Release/netcoreapp3.1
@@ -92,6 +93,40 @@ 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 "::add-path::C:\Program Files\Watchman"
+
     - name: Functional test
       shell: bash
       run: |

Scalar.FunctionalTests/FileSystemRunners/SystemIORunner.cs

@@ -18,7 +18,20 @@ public override bool FileExists(string path)
 
         public override string MoveFile(string sourcePath, string targetPath)
         {
-            File.Move(sourcePath, targetPath);
+            if (RuntimeInformation.IsOSPlatform(OSPlatform.Windows))
+            {
+                File.Move(sourcePath, targetPath);
+            }
+            else
+            {
+                // Use rename(2) on POSIX instead of separate link(2)/unlink(2)
+                // calls, which File.Move() uses to avoid overwriting the
+                // target file should it exist.  However, using link(2)
+                // results in unexpected missed event notifications from
+                // Watchman to Git's fsmonitor hook on some macOS versions,
+                // which in turn results in test failures for Scalar.
+                Rename(sourcePath, targetPath);
+            }
             return string.Empty;
         }
 

Scalar.FunctionalTests/Tools/GitHelpers.cs

@@ -74,8 +74,8 @@ public static void ValidateGitCommand(
             ProcessResult expectedResult = GitProcess.InvokeProcess(controlRepoRoot, command, environmentVariables);
             ProcessResult actualResult = GitHelpers.InvokeGitAgainstScalarRepo(scalarRepoRoot, command, environmentVariables);
 
-            LinesShouldMatch(command + " Errors Lines", actualResult.Errors, expectedResult.Errors);
-            LinesShouldMatch(command + " Output Lines", actualResult.Output, expectedResult.Output);
+            LinesShouldMatch(command + " Errors Lines", expectedResult.Errors, actualResult.Errors);
+            LinesShouldMatch(command + " Output Lines", expectedResult.Output, actualResult.Output);
 
             if (command != "status")
             {

Scalar/CommandLine/CloneVerb.cs

@@ -672,7 +672,7 @@ private Result TryInitRepo()
             GitProcess.Result initResult = GitProcess.Init(this.enlistment);
             if (initResult.ExitCodeIsFailure)
             {
-                string error = string.Format("Could not init repo at to {0}: {1}", repoPath, initResult.Errors);
+                string error = string.Format("Could not init repo at {0}: {1}", repoPath, initResult.Errors);
                 this.tracer.RelatedError(error);
                 return new Result(error);
             }
@@ -694,7 +694,7 @@ private Result TryInitRepo()
                 GitProcess.Result sparseCheckoutResult = GitProcess.SparseCheckoutInit(this.enlistment);
                 if (sparseCheckoutResult.ExitCodeIsFailure)
                 {
-                    string error = string.Format("Could not init sparse-checkout at to {0}: {1}", repoPath, sparseCheckoutResult.Errors);
+                    string error = string.Format("Could not init sparse-checkout at {0}: {1}", repoPath, sparseCheckoutResult.Errors);
                     this.tracer.RelatedError(error);
                     return new Result(error);
                 }

Scripts/Mac/RunFunctionalTests.sh

@@ -7,7 +7,20 @@ if [ -z $CONFIGURATION ]; then
   CONFIGURATION=Debug
 fi
 
-TESTS_EXEC=$SCALAR_OUTPUTDIR/Scalar.FunctionalTests/bin/$CONFIGURATION/netcoreapp3.1/osx-x64/publish/Scalar.FunctionalTests
+PUBLISH_FRAGMENT="bin/$CONFIGURATION/netcoreapp3.1/osx-x64/publish"
+FUNCTIONAL_TESTS_DIR="$SCALAR_OUTPUTDIR/Scalar.FunctionalTests/$PUBLISH_FRAGMENT"
+
+if [ "$2" = "--test-scalar-on-path" ]; then
+  echo "PATH:"
+  echo "$PATH"
+  echo "Scalar location:"
+  where scalar
+else
+  # Copy most recently build Scalar binaries
+  rsync -r "$SCALAR_OUTPUTDIR/Scalar/$PUBLISH_FRAGMENT/" "$FUNCTIONAL_TESTS_DIR"
+fi
+
+TESTS_EXEC="$FUNCTIONAL_TESTS_DIR/Scalar.FunctionalTests"
 
 mkdir ~/Scalar.FT