Rationalize behavior of TestItemsWithUnexpandableMetadata

[KirillOsenkov]

Reenable the test TestItemsWithUnexpandableMetadata

msbuild/src/Build.UnitTests/ConsoleLogger_Tests.cs

Line 324 in 46b723b

public void TestItemsWithUnexpandableMetadata()

Build this project:

<Project DefaultTargets="Build">

  <ItemDefinitionGroup>
    <F>
      <MetadataFileName>a\b\%(Filename).c</MetadataFileName>
    </F>
  </ItemDefinitionGroup>

  <ItemGroup>
    <F Include="-in &quot;x\y\z&quot;" />
  </ItemGroup>

 <Target Name="Build" />

</Project>

The diag console logger currently prints:

Initial Items:
F
    -in "x\y\z"
        MetadataFileName = Cannot expand metadata in expression "a\b\%(Filename).c". The item metadata "%(Filename)" ca
nnot be applied to the path "-in "x\y\z"". Illegal characters in path.

The logger in unit-test TestItemsWithUnexpandableMetadata currently prints:

Initial Items:
F
    -in "x\y\z"
        MetadataFileName = a\b\%(Filename).c

And I don't know why, nor do I know which behavior is better.

[KirillOsenkov]

On main branch, here's how it gets to an invalid file char exception:

Path.CheckInvalidPathChars Line 1394
Path.IsPathRooted Line 1190
FileUtilities.ItemSpecModifiers.IsRootDirectory Line 617
FileUtilities.ItemSpecModifiers.GetItemSpecModifier Line 426
BuiltInMetadata.GetMetadataValueEscaped Line 83
ProjectItemInstance.TaskItem.GetBuiltInMetadataEscaped Line 1843
ProjectItemInstance.TaskItem.BuiltInMetadataTable.GetEscapedValue Line 2178
ProjectItemInstance.TaskItem.BuiltInMetadataTable.GetEscapedValueIfPresent Line 2204
ProjectItemInstance.TaskItem.BuiltInMetadataTable.GetEscapedValue Line 2189
Expander`2.MetadataExpander.MetadataMatchEvaluator.ExpandSingleMetadata Line 1003
RegexReplacement.Replace
Regex.Replace
Regex.Replace
Expander`2.MetadataExpander.ExpandMetadataLeaveEscaped Line 870
Expander`2.ExpandIntoStringLeaveEscaped Line 414
ProjectItemInstance.TaskItem.GetMetadataEscaped Line 1336
ProjectItemInstance.TaskItem.GetMetadata Line 1305
BaseConsoleLogger.OutputItems Line 666
BaseConsoleLogger.WriteItems Line 604
SerialConsoleLogger.ProjectStartedHandler Line 273
EventSourceSink.RaiseProjectStartedEvent Line 548

[KirillOsenkov]

Then the exception bubbles up to here:

msbuild/src/Build/Logging/BaseConsoleLogger.cs

Line 668 in 206d7ae

catch (InvalidProjectFileException e)

[KirillOsenkov]

On ProjectStartedEventArgs, the item in Items is of type ProjectItemInstance.TaskItem, which implements ITaskItem, so calling GetMetadata and catching the exception works here. This doesn't hold for Items on ProjectEvaluationFinished, which have ProjectItem instead of ProjectItemInstance.TaskItem.