dotnet test Failed (Exit Code 1) - Read Failing Tests in CI

One or more tests failed, so dotnet test returns a non-zero exit code and fails the job. The summary line tells you how many failed; the per-test output tells you why.

What this error means

dotnet test ends with a Failed! summary and exit code 1, listing failed tests with their assertion or exception messages. The build compiled fine; the tests themselves did not pass.

dotnet test output

Failed!  - Failed:     2, Passed:   148, Skipped:     0, Total:   150
  Failed Orders.Tests.CheckoutTests.AppliesDiscount [12 ms]
  Error Message:
   Assert.Equal() Failure: Expected: 90, Actual: 100

Common causes

A genuine assertion failure or thrown exception

A test asserted a value that did not match, or the code under test threw. This is a real defect surfaced by the test, not a CI quirk.

Environment difference between local and CI

Tests that depend on time zone, culture, file paths, or environment variables can pass locally and fail on a differently-configured runner.

How to fix it

Reproduce the exact failing test

Run just the failing test with a filter and detailed logging.

Terminal

dotnet test --filter "FullyQualifiedName~CheckoutTests.AppliesDiscount" \
  --logger "console;verbosity=detailed"

Publish results to read failures clearly

Emit a TRX so CI surfaces each failing test and message.

.github/workflows/ci.yml

dotnet test --logger "trx;LogFileName=test-results.trx" \
  --results-directory ./TestResults

Remove environment dependence

Pin culture/time zone in tests that are sensitive to them.
Avoid hard-coded absolute paths; use temp directories.
Inject configuration so tests don’t read host environment variables directly.

How to prevent it

Run the full test suite locally before pushing.
Make tests deterministic and independent of host culture/time/paths.
Publish TRX/JUnit results so failures are easy to triage in CI.