cannot parse csproj files with only one ItemGroup

[amlweems]

If you modify the sample.csproj file to use a single ItemGroup, parsing will fail. For example:

test/sample.csproj:

<Project Sdk="Microsoft.NET.Sdk.Web">
  <PropertyGroup>
    <TargetFramework>netcoreapp3.1</TargetFramework>
    <LangVersion>latest</LangVersion>
  </PropertyGroup>
  <ItemGroup>
    <PackageReference Include="Microsoft.AspNetCore.Mvc.NewtonsoftJson" Version="3.1.1" />
    <PackageReference Include="Microsoft.Bot.Builder.Dialogs" Version="4.8.0" />
    <PackageReference Include="Microsoft.Bot.Builder.Integration.AspNet.Core" Version="4.8.0" />
    <PackageReference Include="Microsoft.Bot.Builder.Adapters.Facebook" Version="4.8.0-rc2-preview" />
    <PackageReference Include="AdaptiveCards" Version="1.0.3" />
  </ItemGroup>
</Project>

$ npm test
...
 FAIL  ./utils.test.js (17.311s)
  ✓ SSRI test (5ms)
  ✓ finds license id from name (1ms)
  ✓ parse gradle dependencies (6ms)
  ✓ get py metadata (123ms)
  ✓ parseGopkgData (6576ms)
  ✓ get crates metadata (225ms)
  ✕ parse cs proj (18ms)
  ✓ get nget metadata (242ms)
  ✓ parsePomFile (22ms)
  ✓ parsePomMetadata (805ms)
  ✓ get repo license (657ms)
  ✓ get go pkg license (510ms)
  ✓ get licenses (2ms)
  ✓ parsePkgLock (11ms)
  ✓ parseNodeShrinkwrap (9ms)
  ✓ parseSetupPyFile (509ms)
  ✓ parsePnpmLock (137ms)
  ✓ parseYarnLock (357ms)
  ✓ parseComposerLock (5ms)
  ✓ parse requirements.txt with comments (1652ms)
  ✓ parse pipfile.lock with hashes (2693ms)
  ✓ parse scala sbt list (2ms)
...
Test Suites: 1 failed, 1 total
Tests:       1 failed, 21 passed, 22 total
Snapshots:   0 total
Time:        17.563s, estimated 24s
Ran all test suites.
npm ERR! Test failed.  See above for more details.