Apply structured assertion messages (RFC 012) to Assert.HasCount / IsEmpty / IsNotEmpty by Evangelink · Pull Request #8262 · microsoft/testfx

Evangelink · 2026-05-15T14:07:57Z

Continues the rollout of RFC 012 — Structured Assertion Messages by migrating Assert.HasCount / Assert.IsEmpty / Assert.IsNotEmpty (including their interpolated-string-handler overloads) to the structured-message format. Follows the patterns established by previously merged work (#8170, #8187, #8210, #8214) and the in-flight series (#8258, #8259, #8260).

Output format

Assert.HasCount(3, collection) (collection has 1 element):

Assertion failed. Expected collection to contain a specific number of elements.

expected count: 3
actual count:   1

Assert.HasCount(3, collection)

Assert.IsEmpty(collection) (collection has 1 element):

Assertion failed. Expected collection to be empty.

expected count: 0
actual count:   1

Assert.IsEmpty(collection)

Assert.IsNotEmpty(Array.Empty<int>()):

Assertion failed. Expected collection to not be empty.

actual count: 0

Assert.IsNotEmpty(Array.Empty<int>())

Notes

Adds HasCountFailedSummary / IsEmptyFailedSummary / IsNotEmptyFailedSummary resource entries (XLF files regenerated via UpdateXlf).
The interpolated-string-handler now passes the developer-built message directly to the structured report so the user-message line appears between the summary and the evidence block (consistent with the rest of RFC 012 migrations).
HasCount reconstructs the call-site as Assert.HasCount(<expected>, <collection>) so the literal expected count remains visible in the call-site line even though it is not captured by CallerArgumentExpression.
Updates the message-format tests in AssertTests.Items.cs to assert against the new layout.

Validation

dotnet build src/TestFramework/TestFramework/TestFramework.csproj -c Debug — clean.
dotnet test test/UnitTests/TestFramework.UnitTests/TestFramework.UnitTests.csproj -c Debug — 3535/3535 passed.

Co-authored-by: Copilot 223556219+Copilot@users.noreply.github.com

…Empty / IsNotEmpty Migrates Assert.HasCount, Assert.IsEmpty, and Assert.IsNotEmpty (and their interpolated-string-handler overloads) to the structured assertion message format defined in RFC 012. The HasCount/IsEmpty evidence block surfaces 'expected count:' and 'actual count:' so the size mismatch is visible at a glance; IsNotEmpty omits the expected line because the only actionable count is the actual zero. The interpolated-string-handler now passes the user-built message directly to the structured report and lets FormatCallSiteExpression reconstruct the call-site (e.g. Assert.HasCount(1, Array.Empty<int>())) so the literal expected count remains visible even on the interpolated path. Updates the affected message-format tests in AssertTests.Items.cs to assert against the new layout. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Copilot

Pull request overview

Migrates Assert.HasCount / Assert.IsEmpty / Assert.IsNotEmpty (including interpolated-string-handler overloads) to the RFC 012 structured assertion message format, updating both resources and unit-test expectations accordingly.

Changes:

Updated Assert.Count failure paths to build StructuredAssertionMessage instances with evidence blocks and call-site expressions.
Added new localized summary resource entries (HasCountFailedSummary, IsEmptyFailedSummary, IsNotEmptyFailedSummary) and regenerated XLFs.
Updated AssertTests.Items expectations to validate the new structured multiline message layout (including interpolated handler scenarios).

Show a summary per file

File	Description
test/UnitTests/TestFramework.UnitTests/Assertions/AssertTests.Items.cs	Updates message assertions to the new structured multiline format for count/empty assertions.
src/TestFramework/TestFramework/Assertions/Assert.Count.cs	Switches HasCount/IsEmpty/IsNotEmpty failure reporting to `StructuredAssertionMessage` with evidence + call-site.
src/TestFramework/TestFramework/Resources/FrameworkMessages.resx	Adds new summary resource strings for the migrated assertions.
src/TestFramework/TestFramework/Resources/xlf/FrameworkMessages.cs.xlf	Regenerated localization entries for new summary strings.
src/TestFramework/TestFramework/Resources/xlf/FrameworkMessages.de.xlf	Regenerated localization entries for new summary strings.
src/TestFramework/TestFramework/Resources/xlf/FrameworkMessages.es.xlf	Regenerated localization entries for new summary strings.
src/TestFramework/TestFramework/Resources/xlf/FrameworkMessages.fr.xlf	Regenerated localization entries for new summary strings.
src/TestFramework/TestFramework/Resources/xlf/FrameworkMessages.it.xlf	Regenerated localization entries for new summary strings.
src/TestFramework/TestFramework/Resources/xlf/FrameworkMessages.ja.xlf	Regenerated localization entries for new summary strings.
src/TestFramework/TestFramework/Resources/xlf/FrameworkMessages.ko.xlf	Regenerated localization entries for new summary strings.
src/TestFramework/TestFramework/Resources/xlf/FrameworkMessages.pl.xlf	Regenerated localization entries for new summary strings.
src/TestFramework/TestFramework/Resources/xlf/FrameworkMessages.pt-BR.xlf	Regenerated localization entries for new summary strings.
src/TestFramework/TestFramework/Resources/xlf/FrameworkMessages.ru.xlf	Regenerated localization entries for new summary strings.
src/TestFramework/TestFramework/Resources/xlf/FrameworkMessages.tr.xlf	Regenerated localization entries for new summary strings.
src/TestFramework/TestFramework/Resources/xlf/FrameworkMessages.zh-Hans.xlf	Regenerated localization entries for new summary strings.
src/TestFramework/TestFramework/Resources/xlf/FrameworkMessages.zh-Hant.xlf	Regenerated localization entries for new summary strings.

Copilot's findings

Files reviewed: 16/16 changed files
Comments generated: 2

Evangelink

Review: RFC 012 migration for `HasCount` / `IsEmpty` / `IsNotEmpty`

The change is correct, well-structured, and consistent with the RFC 012 series. All 21 review dimensions were applied; most are clean. Two minor points are flagged inline:

Findings

Severity	Area	Summary
MODERATE	Code structure	`ReportAssertCountFailed` dispatches on `assertionName == "IsEmpty"` (magic string, twice). Consider splitting into two reporters or using an enum.
NIT	Resources	`HasCountFailMsg` / `IsNotEmptyFailMsg` are now dead strings; still present in `.resx` + all 14 `.xlf` files.

Everything else is clean

Correctness: ReportAssertIsNotEmptyFailed hardcoding "0" is correct (only called when the collection is empty).
HasCount call-site reconstruction: using expectedText (the captured integer value) as expression1 in FormatCallSiteExpression is intentional and correct — the literal expected count is always visible even without a CallerArgumentExpression for it.
XLF files: regenerated via UpdateXlf as stated; not hand-edited. Consistent with localization guidelines.
FrameworkMessages.Designer.cs duplicate hunk in the diff: the file is auto-generated and not tracked in git — the duplicate is a diff artifact, not an actual duplicate in the file.
Test quality: the HEAD of AssertTests.Items.cs uses "Assertion failed." prefix with raw string literals (platform-neutral). No \r\n or fragile assertions.
API surface: no new public API; BuildUserMessageForCollectionExpression cleanly removed. No PublicAPI.Unshipped.txt entry needed.
No threading, security, performance, cross-TFM, or flakiness concerns.

Generated by Expert Code Review (on open) for issue #8262 · ● 17.1M

Use invariant formatting for HasCount call-site arguments while keeping evidence culture-aware, and replace magic assertion-name strings with nameof usage. Add a regression test covering culture-specific negative-sign formatting for the displayed call site. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Evangelink · 2026-05-16T10:55:23Z

@copilot resolve the merge conflicts in this pull request

Co-authored-by: Evangelink <11340282+Evangelink@users.noreply.github.com>

Copilot · 2026-05-16T11:04:37Z

Review: RFC 012 migration for HasCount / IsEmpty / IsNotEmpty

The change is correct, well-structured, and consistent with the RFC 012 series. All 21 review dimensions were applied; most are ...

Addressed in 9ff9009: the dead HasCountFailMsg / IsNotEmptyFailMsg resource entries were removed from FrameworkMessages.resx, the XLFs were regenerated, and the now-unused helper methods in Assert.cs were dropped as part of the same cleanup.

@copilot resolve the merge conflicts in this pull request

Resolved in 9ff9009. I merged origin/main, fixed the conflicts in Assert.Count.cs and FrameworkMessages.resx, regenerated the XLFs, and finalized the merge commit.

Copilot

Copilot's findings

Files reviewed: 17/17 changed files
Comments generated: 2

Evangelink · 2026-05-16T14:30:50Z

+        EvidenceBlock evidence = EvidenceBlock.Create()
+            .AddLine("actual count:", "0");


Done — the evidence value is now formatted via 0.ToString(CultureInfo.CurrentCulture) and reused for the new WithExpectedAndActual(...) call so the evidence respects non-Latin digit cultures, matching the other count-based assertions.

Evangelink · 2026-05-16T14:30:51Z

+
+        StructuredAssertionMessage structured = new(FrameworkMessages.IsNotEmptyFailedSummary);
+        structured.WithUserMessage(userMessage);
+        structured.WithEvidence(evidence);


Done — added structured.WithExpectedAndActual("> 0", actualText) so ExpectedText/ActualText (and the assert.expected/assert.actual data entries) are populated for IsNotEmpty failures, matching the other count-based assertions.

…for IsNotEmpty Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Copilot AI review requested due to automatic review settings May 15, 2026 14:07

Copilot started reviewing on behalf of Evangelink May 15, 2026 14:10 View session

Copilot AI reviewed May 15, 2026

View reviewed changes

Comment thread src/TestFramework/TestFramework/Assertions/Assert.Count.cs Outdated

Comment thread src/TestFramework/TestFramework/Assertions/Assert.Count.cs Outdated

Evangelink commented May 15, 2026

View reviewed changes

Evangelink mentioned this pull request May 15, 2026

Apply structured assertion messages (RFC 012) to Assert.Contains family #8265

Merged

Copilot started work on behalf of Evangelink May 16, 2026 10:55 View session

Merge origin/main into dev/amauryleve/assert-count-rfc012

9ff9009

Co-authored-by: Evangelink <11340282+Evangelink@users.noreply.github.com>

Copilot AI review requested due to automatic review settings May 16, 2026 11:04

Evangelink review requested due to automatic review settings May 16, 2026 11:04

Copilot finished work on behalf of Evangelink May 16, 2026 11:06

Evangelink commented May 16, 2026

View reviewed changes

Comment thread test/UnitTests/TestFramework.UnitTests/Assertions/AssertTests.Items.cs Outdated

Apply suggestion from @Evangelink

201784a

Copilot AI review requested due to automatic review settings May 16, 2026 11:48

Copilot started reviewing on behalf of Evangelink May 16, 2026 11:49 View session

Copilot AI reviewed May 16, 2026

View reviewed changes

Address review: culture-aware actual count and WithExpectedAndActual …

ef50f91

…for IsNotEmpty Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Evangelink mentioned this pull request May 16, 2026

Fix TelemetryTests flake from parallel dotnet test races #8292

Open

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

Apply structured assertion messages (RFC 012) to Assert.HasCount / IsEmpty / IsNotEmpty#8262

Apply structured assertion messages (RFC 012) to Assert.HasCount / IsEmpty / IsNotEmpty#8262
Evangelink wants to merge 5 commits into
mainfrom
dev/amauryleve/assert-count-rfc012

Evangelink commented May 15, 2026

Uh oh!

Copilot AI left a comment

Uh oh!

Uh oh!

Uh oh!

Evangelink left a comment

Uh oh!

Evangelink commented May 16, 2026

Uh oh!

Copilot AI commented May 16, 2026 •

edited

Loading

Review: RFC 012 migration for `HasCount` / `IsEmpty` / `IsNotEmpty`

Uh oh!

Uh oh!

Copilot AI left a comment

Uh oh!

Evangelink May 16, 2026

Uh oh!

Evangelink May 16, 2026

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

4 participants

		EvidenceBlock evidence = EvidenceBlock.Create()
		.AddLine("actual count:", "0");

Conversation

Evangelink commented May 15, 2026

Output format

Notes

Validation

Uh oh!

Copilot AI left a comment

Choose a reason for hiding this comment

Pull request overview

Copilot's findings

Uh oh!

Uh oh!

Uh oh!

Evangelink left a comment

Choose a reason for hiding this comment

Review: RFC 012 migration for HasCount / IsEmpty / IsNotEmpty

Findings

Everything else is clean

Uh oh!

Evangelink commented May 16, 2026

Uh oh!

Copilot AI commented May 16, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Review: RFC 012 migration for HasCount / IsEmpty / IsNotEmpty

Uh oh!

Uh oh!

Copilot AI left a comment

Choose a reason for hiding this comment

Copilot's findings

Uh oh!

Evangelink May 16, 2026

Choose a reason for hiding this comment

Uh oh!

Evangelink May 16, 2026

Choose a reason for hiding this comment

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

4 participants

Review: RFC 012 migration for `HasCount` / `IsEmpty` / `IsNotEmpty`

Copilot AI commented May 16, 2026 •

edited

Loading

Review: RFC 012 migration for `HasCount` / `IsEmpty` / `IsNotEmpty`