Test Explorer: every run reports "No result reported" — discovered ids carry xUnit's unique-ID suffix

[MelbourneDeveloper]

Summary

Running any test from the Test Explorer against FluentValidation fails every test with

No result reported for FluentValidation.Tests.AbstractValidatorTester.When_the_validators_fail_then_the_errors_Should_be_accessible_via_the_errors_property (filter matched no test)

0/35 — nothing executed. The tree also renders every test with a 40-hex suffix in its label:

Can_replace_default_errorcode_resolver (15cf31e476658caedccc20a4b3fef02631fa4692)
CanValidateInstancesOfType_returns_false_when_comparing_against_some_other_type (2258dba774d9e515c4b…)
Default_error_code_should_be_class_name (fefa0728fbd9239435494fa7c4c1bbb801282c96)

Those two symptoms are the same defect. Run, Debug and Run-with-Coverage are all unusable on any project whose VSTest adapter emits this shape.

Root cause (confirmed on disk)

dotnet vstest … --ListFullyQualifiedTests does not always write a bare TestCase.FullyQualifiedName. With xunit.runner.visualstudio 2.2.0 (the version FluentValidation.Tests pins) it appends the test case's unique ID:

$ dotnet vstest bin/Debug/net8.0/FluentValidation.Tests.dll \
    --ListFullyQualifiedTests --ListTestsTargetPath:fqn.txt

$ head -3 fqn.txt
FluentValidation.Tests.AbstractValidatorTester.When_the_Validators_pass_then_the_validatorRunner_should_return_true (2bd9e5a56e8ea7c7114cb93b1c19bd50a55b7bf4)
FluentValidation.Tests.AbstractValidatorTester.When_the_validators_fail_then_validatorrunner_should_return_false (3695ae1728b33597f39bc187619010fc9c8b9fd1)
FluentValidation.Tests.AbstractValidatorTester.When_the_validators_fail_then_the_errors_Should_be_accessible_via_the_errors_property (4159b661adc378e56bd9b129de348febd7bf97e3)

813 of 816 listed names carry the suffix. parseFullyQualifiedTestList takes every line verbatim (src/editors/vscode/src/test-discovery.ts:135-138) — deliberately, because F# backtick names contain spaces and no shape filter is admissible — so the suffix becomes part of the test id.

From there the whole run path is poisoned:

Stage	Value	Result
makeTestItem (testing.ts:347)	label = last dotted segment	Method (4159b661…) in the tree
filterClause (test-filter.ts:32)	FullyQualifiedName=…Method \(4159b661…\)	parens escaped per [TEST-FILTER-ESCAPE]; no test has that name
parseTrxReport (test-trx.ts:146-153)	keys on TestMethod/@className + . + @name	bare FQN, never the suffixed one
reportMissing (test-reporting.ts:82)	id absent from the TRX map	No result reported for … (filter matched no test)

So the filter can never match, and even if it did the TRX key would not line up with the id.

The repo's own fixtures use xunit.runner.visualstudio 2.8.2, which emits bare FQNs — which is why the whole [TEST-DISCOVERY-FQN] e2e suite is green while a real-world project is completely broken.

Reproduction

1. Open src/fixtures/real-world/fluentvalidation (or any project on xunit.runner.visualstudio 2.2.0).
2. Open the Testing view and refresh.
3. Observe the (40-hex) suffix on every test label.
4. Press ▶ on the root. Every test errors with No result reported for ….

Expected

• Test ids are the bare Namespace.Class.Method FQN, whatever the adapter appended.
• Labels show the method name alone.
• --filter matches and TRX outcomes attribute per test.

Notes for the fix

The suffix must be distinguished from names that legitimately end in parentheses — [TEST-DISCOVERY-FQN] requires Cs.Nunit.Fixtures.CalculatorTests.Adds_Case(2,2,4) to round-trip unchanged. The two differ: the adapter suffix is preceded by a space and its content is hex only.

Collapsing several xUnit theory rows onto one bare FQN is correct and already the documented behaviour ("xUnit [Theory] … no row data"); parseFullyQualifiedTestList already de-duplicates.

Environment

• Windows 11, .NET SDK 10.0.303
• SharpLsp branch fixloading
• FluentValidation.Tests: <TargetFrameworks>net8.0;net9.0</TargetFrameworks>, xunit 2.2.0, xunit.runner.visualstudio 2.2.0, Microsoft.NET.Test.Sdk 16.0.1

[MelbourneDeveloper]

Fixed on fixloading (not yet merged).

Fix — src/editors/vscode/src/test-names.ts, a new module owning the name listings VSTest writes. parseFullyQualifiedTestList now strips an adapter-appended unique ID before the name becomes an id, and de-duplicates after stripping so a theory's rows collapse onto the one name they share instead of surviving as one leaf per row.

The match is deliberately narrow — a SPACE, then exactly 40 hex digits in parentheses, at the end of the name — so the NUnit [TestCase] shape Ns.Class.Adds_Case(2,2,4) (no space, not hex) round-trips untouched as [TEST-DISCOVERY-FQN] requires. Scanned rather than regex-matched, per escapeFilterValue.

test-discovery.ts shed the listing readers to make room and stayed under the 500-line ceiling; HEX_DIGITS is now declared once and shared.

Verified against the real listing — all 816 names from FluentValidation.Tests parse bare:

raw lines:       816
parsed ids:      816
still decorated: 0
  FluentValidation.Tests.AbstractValidatorTester.When_the_Validators_pass_then_the_validatorRunner_should_return_true
  FluentValidation.Tests.AbstractValidatorTester.When_the_validators_fail_then_validatorrunner_should_return_false
NUnit shape preserved: ["Cs.Nunit.Fixtures.CalculatorTests.Adds_Case(2,2,4)"]

Regression test — src/test/suite/test-explorer-adapter-ids.test.ts, a new e2e suite building a real project pinned to xunit.runner.visualstudio 2.2.0 (XUNIT_LEGACY_PACKAGES, pinned deliberately). It opens with a vacuity guard that re-runs the listing pass and asserts the adapter really does decorate every name it reports — without that, the suite would go green on a modern adapter while proving nothing.

Before the fix it failed exactly as this issue describes:

- "Adds_Theory (3469d742507a3127c4abd52c8484750152378eda)"
- "Adds_Theory (56a6d05610a4a652c0342ea85dba5d76ddb65721)"
- "Adds_TwoNumbers (e4e85098ea57f4896cc7913c4aba301b45b43066)"
+ "Adds_Theory"
+ "Adds_TwoNumbers"

▶ reports a REAL outcome per test — never "No result reported":
  Cs.XunitLegacy.Fixtures.CalculatorTests.Adds_TwoNumbers must be in the tree before it can be run

Note the theory rows: the suffix was also splitting one [Theory] into a leaf per row.

After:

✔ the adapter really does decorate its names, so this suite cannot pass vacuously
✔ discovered ids are the BARE fully-qualified names, with no adapter suffix
✔ the tree shows the METHOD name, not a hex blob
✔ ▶ reports a REAL outcome per test — never "No result reported"

The last one is the whole complaint: it runs the tests for real and asserts passed / failed / skipped are each attributed from the TRX report.

[TEST-DISCOVERY-FQN] updated to specify the decoration and the NUnit shape it must not touch.