Skip env processing on matrix import step

eng/common-tests/matrix-generator/tests/job-matrix-functions.modification.tests.ps1

@@ -388,6 +388,23 @@ Describe "Platform Matrix Import" -Tag "import" {
         { GenerateMatrix $importConfig "sparse" } | Should -Throw
     }
 
+    It "Should process filters against env references in imported matrix in the correct order" {
+        $matrixJson = @'
+{
+    "matrix": {
+        "$IMPORT": "./matrix-generator/tests/test-import-matrix-env.json",
+        "BarEnv": "env:BAR"
+    }
+}
+'@
+
+        [System.Environment]::SetEnvironmentVariable("FOO", "Value1")
+        [System.Environment]::SetEnvironmentVariable("BAR", "Value2")
+        $importConfig = GetMatrixConfigFromJson $matrixJson
+        [array]$matrix = GenerateMatrix $importConfig "sparse" -filter @("FooEnv=.*FOO.*")
+
+        $matrix[0].name | Should -Be Value2_Value1
+    }
 }
 
 Describe "Platform Matrix Replace" -Tag "UnitTest", "replace" {

eng/common-tests/matrix-generator/tests/test-import-matrix-env.json

@@ -0,0 +1,5 @@
+{
+  "matrix": {
+    "FooEnv": "env:FOO"
+  }
+}

eng/common/scripts/job-matrix/job-matrix-functions.ps1

@@ -96,7 +96,8 @@ function GenerateMatrix(
     [String]$displayNameFilter = ".*",
     [Array]$filters = @(),
     [Array]$replace = @(),
-    [Array]$nonSparseParameters = @()
+    [Array]$nonSparseParameters = @(),
+    [Switch]$skipEnvironmentVariables
 ) {
     $matrixParameters, $importedMatrix, $combinedDisplayNameLookup = `
         ProcessImport $config.matrixParameters $selectFromMatrixType $nonSparseParameters $config.displayNamesLookup
@@ -124,7 +125,9 @@ function GenerateMatrix(
 
     $matrix = FilterMatrix $matrix $filters
     $matrix = ProcessReplace $matrix $replace $combinedDisplayNameLookup
-    $matrix = ProcessEnvironmentVariableReferences $matrix $combinedDisplayNameLookup
+    if (!$skipEnvironmentVariables) {
+        $matrix = ProcessEnvironmentVariableReferences $matrix $combinedDisplayNameLookup
+    }
     $matrix = FilterMatrixDisplayName $matrix $displayNameFilter
     return $matrix
 }
@@ -427,10 +430,14 @@ function ProcessImport([MatrixParameter[]]$matrix, [String]$selection, [Array]$n
         exit 1
     }
     $importedMatrixConfig = GetMatrixConfigFromFile (Get-Content -Raw $importPath)
+    # Add skipEnvironmentVariables so we don't process environment variables on import
+    # because we want top level filters to work against the the env key, not the value.
+    # The environment variables will get resolved after the import.
     $importedMatrix = GenerateMatrix `
         -config $importedMatrixConfig `
         -selectFromMatrixType $selection `
-        -nonSparseParameters $nonSparseParameters
+        -nonSparseParameters $nonSparseParameters `
+        -skipEnvironmentVariables
 
     $combinedDisplayNameLookup = $importedMatrixConfig.displayNamesLookup
     foreach ($lookup in $displayNamesLookup.GetEnumerator()) {