[msbuild] Fix multiple resource prefixes support. Fixes #20968 by rolfbjarne · Pull Request #26020 · dotnet/macios

rolfbjarne · 2026-07-09T16:57:30Z

This PR adds support for multiple semicolon-separated values in AppBundleResourcePrefix (and the legacy IPhoneResourcePrefix/XamMacResourcePrefix properties).

Previously, setting e.g. <AppBundleResourcePrefix>Resources;PlatformResources</AppBundleResourcePrefix> didn't work correctly because the $(_ResourcePrefix)\**\* glob pattern in DefaultItems.props treated the semicolons as MSBuild item separators — only the last path got the glob suffix, while earlier paths were treated as literal file includes.

Fix

Convert _ResourcePrefix into an intermediate item list (_ResourcePrefixItem) and use MSBuild item transforms (@(_ResourcePrefixItem->'%(Identity)\**\*')) to generate correct glob patterns for each prefix path. The same approach is applied to all Exclude patterns.

The C# task layer (BundleResource.SplitResourcePrefixes) already handled multiple prefixes correctly, so no changes were needed there.

Tests

Unit tests verifying property propagation with multiple prefixes
Unit tests verifying BundleResource item inclusion from multiple prefix directories
E2E test project (AppWithMultipleResourcePrefixes) that builds an app with two resource prefix directories and validates the app bundle contains resources from both

Fixes #20968

🤖 Pull request created by Copilot

Add unit tests and an E2E test to verify that semicolon-separated multiple prefixes in AppBundleResourcePrefix (and the legacy IPhoneResourcePrefix/XamMacResourcePrefix) work correctly. Unit tests (in ResourcePrefixTest.cs): - Property value propagation with multiple prefixes - AppBundleResourcePrefix with multiple prefixes - BundleResource item inclusion from single/multiple prefix directories - BundleResource items when only the second prefix has files - BundleResource items in subdirectories of multiple prefixes - Three or more semicolon-separated prefixes E2E test (AppWithMultipleResourcePrefixes): - On-disk project with AppBundleResourcePrefix set to 'Resources;PlatformResources' - Resource files in both directories (including subdirectories) - Builds for all platforms and validates the app bundle contains resources from both prefix directories These tests exercise the behavior described in issue #20968, where the $(_ResourcePrefix)\\**\\* glob pattern in the BundleResource Include may not expand correctly for multiple semicolon-separated values. Fixes #20968 Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>

The BundleResource Include pattern used $(_ResourcePrefix)\\**\\* which doesn't work when _ResourcePrefix contains multiple semicolon-separated paths (e.g. 'Resources;PlatformResources'). MSBuild treats the semicolons as item separators, so only the last path would get the glob suffix applied, and the first paths would be treated as literal file includes. Fix this by converting the _ResourcePrefix property into an item list (_ResourcePrefixItem) and using MSBuild item transforms (@(_ResourcePrefixItem->'%(Identity)\\**\\*')) to generate the correct glob pattern for each prefix path. The same approach is applied to all the Exclude patterns. The C# task layer (BundleResource.SplitResourcePrefixes) already handles multiple prefixes correctly, so no changes are needed there. Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>

Item transforms (@(Item->'transform')) don't expand globs in MSBuild - the resulting strings are treated as literal file paths. Instead, use $(_ResourcePrefix.Replace(';','\**\*;'))\**\* which produces a property expansion that MSBuild properly evaluates as glob patterns. Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>

Copilot

Pull request overview

This PR fixes MSBuild default BundleResource globbing so that _ResourcePrefix can contain multiple semicolon-separated resource prefix paths (from AppBundleResourcePrefix and legacy prefix properties), and adds unit/E2E coverage to prevent regressions.

Changes:

Update Microsoft.Sdk.DefaultItems.template.props to correctly apply \**\* (and exclusion patterns) to each semicolon-separated prefix entry.
Add unit tests validating multi-prefix property propagation and BundleResource item inclusion across multiple prefix directories.
Add a new end-to-end test project (AppWithMultipleResourcePrefixes) with resources split across two prefixes and validated in the built app bundle.

Reviewed changes

Copilot reviewed 26 out of 26 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
tests/dotnet/UnitTests/ResourcePrefixTest.cs	Adds unit tests + E2E validation for multiple resource prefixes and bundle contents.
dotnet/targets/Microsoft.Sdk.DefaultItems.template.props	Fixes `BundleResource` Include/Exclude patterns to work with semicolon-separated resource prefixes.
tests/dotnet/AppWithMultipleResourcePrefixes/AppDelegate.cs	Minimal app entrypoint for the E2E build test project.
tests/dotnet/AppWithMultipleResourcePrefixes/shared.csproj	Shared test project settings, including `AppBundleResourcePrefix=Resources;PlatformResources`.
tests/dotnet/AppWithMultipleResourcePrefixes/shared.mk	Shared make include for running the E2E test project via existing dotnet test infrastructure.
tests/dotnet/AppWithMultipleResourcePrefixes/shared.plist	Shared (minimal) partial app manifest for the E2E test project.
tests/dotnet/AppWithMultipleResourcePrefixes/iOS/AppWithMultipleResourcePrefixes.csproj	iOS project wrapper importing shared settings.
tests/dotnet/AppWithMultipleResourcePrefixes/iOS/Makefile	iOS test project make include.
tests/dotnet/AppWithMultipleResourcePrefixes/iOS/Resources/SharedResource.txt	Resource file from the first prefix for iOS.
tests/dotnet/AppWithMultipleResourcePrefixes/iOS/PlatformResources/PlatformResource.txt	Resource file from the second prefix for iOS.
tests/dotnet/AppWithMultipleResourcePrefixes/iOS/PlatformResources/SubDir/SubDirResource.txt	Subdirectory resource under the second prefix for iOS.
tests/dotnet/AppWithMultipleResourcePrefixes/tvOS/AppWithMultipleResourcePrefixes.csproj	tvOS project wrapper importing shared settings.
tests/dotnet/AppWithMultipleResourcePrefixes/tvOS/Makefile	tvOS test project make include.
tests/dotnet/AppWithMultipleResourcePrefixes/tvOS/Resources/SharedResource.txt	Resource file from the first prefix for tvOS.
tests/dotnet/AppWithMultipleResourcePrefixes/tvOS/PlatformResources/PlatformResource.txt	Resource file from the second prefix for tvOS.
tests/dotnet/AppWithMultipleResourcePrefixes/tvOS/PlatformResources/SubDir/SubDirResource.txt	Subdirectory resource under the second prefix for tvOS.
tests/dotnet/AppWithMultipleResourcePrefixes/MacCatalyst/AppWithMultipleResourcePrefixes.csproj	Mac Catalyst project wrapper importing shared settings.
tests/dotnet/AppWithMultipleResourcePrefixes/MacCatalyst/Makefile	Mac Catalyst test project make include.
tests/dotnet/AppWithMultipleResourcePrefixes/MacCatalyst/Resources/SharedResource.txt	Resource file from the first prefix for Mac Catalyst.
tests/dotnet/AppWithMultipleResourcePrefixes/MacCatalyst/PlatformResources/PlatformResource.txt	Resource file from the second prefix for Mac Catalyst.
tests/dotnet/AppWithMultipleResourcePrefixes/MacCatalyst/PlatformResources/SubDir/SubDirResource.txt	Subdirectory resource under the second prefix for Mac Catalyst.
tests/dotnet/AppWithMultipleResourcePrefixes/macOS/AppWithMultipleResourcePrefixes.csproj	macOS project wrapper importing shared settings.
tests/dotnet/AppWithMultipleResourcePrefixes/macOS/Makefile	macOS test project make include.
tests/dotnet/AppWithMultipleResourcePrefixes/macOS/Resources/SharedResource.txt	Resource file from the first prefix for macOS.
tests/dotnet/AppWithMultipleResourcePrefixes/macOS/PlatformResources/PlatformResource.txt	Resource file from the second prefix for macOS.
tests/dotnet/AppWithMultipleResourcePrefixes/macOS/PlatformResources/SubDir/SubDirResource.txt	Subdirectory resource under the second prefix for macOS.

MSBuild glob expansion only works for literal strings and simple property expansions in Include attributes. Item transforms and property functions both produce strings that are treated as literal identities without glob expansion or semicolon splitting. Fix multi-prefix by: - In DefaultItems.props: keep the original glob for single-prefix only (via Contains(';') condition), and populate a _ResourcePrefixItem list for multi-prefix. - In Xamarin.Shared.targets: add _ExpandMultipleResourcePrefixes target that uses batched glob expansion (%(_ResourcePrefixItem.Identity)) inside a Target ItemGroup, which correctly expands globs per prefix. Also update unit tests to pass the target name to -getItem: so that target-created items are visible in the query results. Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>

Using %() metadata references in Exclude attributes within target ItemGroups can cause MSB5029 parsing errors in some MSBuild versions. Switch to Include followed by separate Remove entries, which achieves the same result without the parsing issue. Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>

When using %(_ResourcePrefixItem.Identity) batching for the Include, %(FullPath) in the Link metadata resolves to the _ResourcePrefixItem's FullPath (the directory) instead of the newly included BundleResource item's FullPath. This caused Link to be set to just 'Resources' instead of 'Resources/SharedResource.txt', breaking the logical name computation in CollectBundleResources. Remove Link entirely — the CollectBundleResources task computes the logical name correctly from the item's Identity (which is already relative to the project directory) combined with the ResourcePrefix property. Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>

rolfbjarne · 2026-07-22T13:02:13Z

/review

github-actions · 2026-07-22T13:02:57Z

❌ .NET for Apple Platforms PR Reviewer failed. Please review the logs for details.

rolfbjarne

❌ Reject — 1 error.

The multi-prefix expansion is well covered across platforms, and CI is green. However, the exclusion pass currently mutates the complete BundleResource item group, so projects using multiple prefixes can lose explicitly declared resources. Please scope the removals to an intermediate set of newly globbed default items before adding that set to BundleResource.

…iphoneresourceprefix-maybe-supports-mult-7b2bb4

- Use intermediate _DefaultBundleResourceCandidate item for exclusions so that Remove operations don't affect explicitly declared BundleResource items (fixes scoping issue). - Use -arm64 instead of -x64 in E2E test cases. - Remove null-forgiving operator in GetBundleResourceIdentities. Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>

Instead of expanding multi-prefix resources in a target (which prevents items from showing up in the IDE without building), use Split(';')[N] property functions to extract each prefix individually in the DefaultItems.props file. This way, all BundleResource items are available at evaluation time. Up to 3 semicolon-separated resource prefix paths are supported. An error is raised at build time if more than 3 are specified. Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com> Copilot-Session: 23a9f378-955d-436d-8d29-4c754cac5f88

rolfbjarne · 2026-08-03T11:36:20Z

Addressed the review comment in adaac25: moved multi-prefix expansion out of the target and into the .props file using Split(';')[N] property functions. Each prefix gets its own BundleResource Include/Exclude entry at evaluation time, so items show up in the IDE without building. Limited to 3 prefixes with a build-time error if exceeded.

Define _ResourcePrefix_1, _ResourcePrefix_2, _ResourcePrefix_3 properties in Xamarin.Shared.props, and use those simple property references in DefaultItems.template.props instead of repeating the verbose $([System.String]::new('$(_ResourcePrefixPadded)').Split(';')[N]) expression everywhere. Much cleaner and easier to read. Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com> Copilot-Session: 23a9f378-955d-436d-8d29-4c754cac5f88

Use '$(_ResourcePrefix_N)' != '' conditions instead of checking _ResourcePrefixCount. This handles edge cases like 'prefix;;' where empty entries between semicolons should be ignored. Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com> Copilot-Session: 23a9f378-955d-436d-8d29-4c754cac5f88

…ybe-supports-mult-7b2bb4

vs-mobiletools-engineering-service2 · 2026-08-03T17:30:31Z

✅ API diff for current PR / commit

NET (empty diffs)

iOS: vsdrops gist ( No breaking changes )
tvOS: vsdrops gist ( No breaking changes )
MacCatalyst: vsdrops gist ( No breaking changes )
macOS: vsdrops gist ( No breaking changes )

✅ API diff vs stable

NET (empty diffs)

iOS: vsdrops gist ( No breaking changes )
tvOS: vsdrops gist ( No breaking changes )
MacCatalyst: vsdrops gist ( No breaking changes )
macOS: vsdrops gist ( No breaking changes )

ℹ️ Generator diff

Generator Diff: vsdrops (html) vsdrops (raw diff) gist (raw diff) - Please review changes)

Pipeline on Agent
Hash: 785a1126609e72451a6bcc48fb0686d2cee6a3ee [PR build]

vs-mobiletools-engineering-service2 · 2026-08-03T19:36:44Z

🚀 [CI Build #785a112] Test results 🚀

Test results

✅ All tests passed on VSTS: test results.

🎉 All 203 tests passed 🎉

Tests counts

✅ assembly-processing: All 1 tests passed. Html Report (VSDrops) Download
✅ cecil: All 1 tests passed. Html Report (VSDrops) Download
✅ dotnettests (iOS): All 1 tests passed. Html Report (VSDrops) Download
✅ dotnettests (MacCatalyst): All 1 tests passed. Html Report (VSDrops) Download
✅ dotnettests (macOS): All 1 tests passed. Html Report (VSDrops) Download
✅ dotnettests (Multiple platforms): All 1 tests passed. Html Report (VSDrops) Download
✅ dotnettests (tvOS): All 1 tests passed. Html Report (VSDrops) Download
✅ framework: All 2 tests passed. Html Report (VSDrops) Download
✅ fsharp: All 4 tests passed. Html Report (VSDrops) Download
✅ generator: All 5 tests passed. Html Report (VSDrops) Download
✅ interdependent-binding-projects: All 4 tests passed. Html Report (VSDrops) Download
✅ introspection: All 4 tests passed. Html Report (VSDrops) Download
✅ linker (iOS): All 15 tests passed. Html Report (VSDrops) Download
✅ linker (MacCatalyst): All 15 tests passed. Html Report (VSDrops) Download
✅ linker (macOS): All 21 tests passed. Html Report (VSDrops) Download
✅ linker (tvOS): All 15 tests passed. Html Report (VSDrops) Download
✅ monotouch (iOS): All 19 tests passed. Html Report (VSDrops) Download
✅ monotouch (MacCatalyst): All 18 tests passed. Html Report (VSDrops) Download
✅ monotouch (macOS): All 19 tests passed. Html Report (VSDrops) Download
✅ monotouch (tvOS): All 19 tests passed. Html Report (VSDrops) Download
✅ msbuild: All 2 tests passed. Html Report (VSDrops) Download
✅ sharpie: All 1 tests passed. Html Report (VSDrops) Download
✅ windows: All 3 tests passed. Html Report (VSDrops) Download
✅ xcframework: All 4 tests passed. Html Report (VSDrops) Download
✅ xtro: All 1 tests passed. Html Report (VSDrops) Download

macOS tests

✅ Tests on macOS Monterey (12): All 5 tests passed. Html Report (VSDrops) Download
✅ Tests on macOS Ventura (13): All 5 tests passed. Html Report (VSDrops) Download
✅ Tests on macOS Sonoma (14): All 5 tests passed. Html Report (VSDrops) Download
✅ Tests on macOS Sequoia (15): All 5 tests passed. Html Report (VSDrops) Download
✅ Tests on macOS Tahoe (26): All 5 tests passed. Html Report (VSDrops) Download

Linux Build Verification

✅ Linux build succeeded

Pipeline on Agent
Hash: 785a1126609e72451a6bcc48fb0686d2cee6a3ee [PR build]

rolfbjarne added the copilot label Jul 9, 2026

This comment has been minimized.

Sign in to view

rolfbjarne requested a review from Copilot July 15, 2026 12:09

Copilot started reviewing on behalf of rolfbjarne July 15, 2026 12:09 View session

Copilot AI reviewed Jul 15, 2026

View reviewed changes

Comment thread tests/dotnet/UnitTests/ResourcePrefixTest.cs

Comment thread tests/dotnet/UnitTests/ResourcePrefixTest.cs Outdated

This comment has been minimized.

Sign in to view

rolfbjarne commented Jul 22, 2026

View reviewed changes

Comment thread tests/dotnet/UnitTests/ResourcePrefixTest.cs Outdated

rolfbjarne commented Jul 22, 2026

View reviewed changes

Comment thread msbuild/Xamarin.Shared/Xamarin.Shared.targets Outdated

rolfbjarne and others added 2 commits July 22, 2026 15:46

Merge remote-tracking branch 'origin/main' into dev/rolf/issue-20968-…

81be669

…iphoneresourceprefix-maybe-supports-mult-7b2bb4

This comment has been minimized.

Sign in to view

rolfbjarne requested a review from mauroa as a code owner July 27, 2026 18:12

This comment has been minimized.

Sign in to view

rolfbjarne requested a review from dalexsoto as a code owner August 3, 2026 11:36

rolfbjarne commented Aug 3, 2026

View reviewed changes

Comment thread msbuild/Xamarin.Shared/Xamarin.Shared.targets Outdated

rolfbjarne commented Aug 3, 2026

View reviewed changes

Comment thread msbuild/Xamarin.Shared/Xamarin.Shared.props Outdated

This comment has been minimized.

Sign in to view

Merge branch 'main' into dev/rolf/issue-20968-iphoneresourceprefix-ma…

785a112

…ybe-supports-mult-7b2bb4

rolfbjarne added the ready-to-review This PR is ready to review/merge. label Aug 3, 2026

dalexsoto approved these changes Aug 3, 2026

View reviewed changes

Uh oh!

Conversation

rolfbjarne commented Jul 9, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Fix

Tests

Uh oh!

This comment has been minimized.

This comment has been minimized.

This comment has been minimized.

This comment has been minimized.

This comment has been minimized.

Copilot AI left a comment

Choose a reason for hiding this comment

Pull request overview

Reviewed changes

Uh oh!

Uh oh!

Uh oh!

This comment has been minimized.

This comment has been minimized.

This comment has been minimized.

This comment has been minimized.

This comment has been minimized.

This comment has been minimized.

This comment has been minimized.

This comment has been minimized.

Uh oh!

rolfbjarne commented Jul 22, 2026

Uh oh!

github-actions Bot commented Jul 22, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

rolfbjarne left a comment

Choose a reason for hiding this comment

Uh oh!

Uh oh!

This comment has been minimized.

This comment has been minimized.

This comment has been minimized.

rolfbjarne commented Aug 3, 2026

Uh oh!

Uh oh!

Uh oh!

This comment has been minimized.

This comment has been minimized.

This comment has been minimized.

This comment has been minimized.

This comment has been minimized.

This comment has been minimized.

This comment has been minimized.

This comment has been minimized.

This comment has been minimized.

This comment has been minimized.

This comment has been minimized.

This comment has been minimized.

This comment has been minimized.

This comment has been minimized.

This comment has been minimized.

vs-mobiletools-engineering-service2 commented Aug 3, 2026

✅ API diff for current PR / commit

✅ API diff vs stable

ℹ️ Generator diff

Uh oh!

vs-mobiletools-engineering-service2 commented Aug 3, 2026

🚀 [CI Build #785a112] Test results 🚀

Test results

Tests counts

macOS tests

Linux Build Verification

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

4 participants

rolfbjarne commented Jul 9, 2026 •

edited

Loading

github-actions Bot commented Jul 22, 2026 •

edited

Loading