diff --git a/.github/workflows/pull-request.yml b/.github/workflows/pull-request.yml
index 041d95b..94ae9e5 100644
--- a/.github/workflows/pull-request.yml
+++ b/.github/workflows/pull-request.yml
@@ -1,5 +1,12 @@
 name: Pull request
-on: pull_request
+
+on:
+  pull_request:
+    types: [opened, reopened, synchronize, ready_for_review]  
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
 
 env:
   XCODE_VERSION: "16.3"
@@ -92,6 +99,7 @@ jobs:
     - name: Build (SPM)
       if: ${{ matrix.platform == 'macos' }}
       run: swift build
+
     - name: Build (Xcode)
       if: ${{ matrix.platform != 'macos' }}
       run: |
@@ -105,7 +113,13 @@ jobs:
       if: ${{ matrix.platform == 'macos' }}
       run: |
         set -o pipefail
-        swift test | xcbeautify --renderer github-actions
+        swift test --enable-code-coverage | xcbeautify --renderer github-actions
+        TEST_BUNDLE=$(find .build/debug/ -name "*.xctest" | head -n 1)
+        TEST_EXECUTABLE="$TEST_BUNDLE/Contents/MacOS/$(basename "$TEST_BUNDLE" .xctest)"
+        xcrun llvm-cov export -format="lcov" \
+          -instr-profile .build/debug/codecov/default.profdata \
+          "$TEST_EXECUTABLE" > info.lcov
+
     - name: Test (Xcode)
       if: ${{ matrix.platform != 'macos' }}
       run: |
@@ -114,3 +128,9 @@ jobs:
           -scheme ${{ needs.prepare.outputs.scheme }} \
           -destination "${{ steps.destination.outputs.destination }}" | \
           xcbeautify --renderer github-actions
+
+    - name: Check coverage (SPM)
+      if: ${{ matrix.platform == 'macos' }}
+      uses: codecov/codecov-action@v5
+      with:
+        fail_ci_if_error: true
\ No newline at end of file
diff --git a/.github/workflows/release.yml b/.github/workflows/release.yml
index bce3182..d109093 100644
--- a/.github/workflows/release.yml
+++ b/.github/workflows/release.yml
@@ -1,4 +1,5 @@
 name: Release
+
 on:
   push:
     tags:
diff --git a/.spi.yml b/.spi.yml
new file mode 100644
index 0000000..775dd8a
--- /dev/null
+++ b/.spi.yml
@@ -0,0 +1,7 @@
+version: 1
+builder:
+  configs:
+    - documentation_targets:
+      - Principle
+      - PrincipleConcurrency
+      - PrincipleCollections
diff --git a/README.md b/README.md
index 45d1775..d8dc9d4 100644
--- a/README.md
+++ b/README.md
@@ -1,6 +1,7 @@
 # Principle
 
 ![Swift](https://img.shields.io/badge/Swift-6.0-EF5239?logo=swift&labelColor=white)
+[![Codecov](https://codecov.io/gh/NSFatalError/Principle/graph/badge.svg?token=ITK16CK7NL)](https://codecov.io/gh/NSFatalError/Principle)
 
 Essential tools that extend the capabilities of Swift Standard Library.
 
diff --git a/Tests/PrincipleConcurrencyTests/SingleUseTransferTests.swift b/Tests/PrincipleConcurrencyTests/SingleUseTransferTests.swift
new file mode 100644
index 0000000..214d5ef
--- /dev/null
+++ b/Tests/PrincipleConcurrencyTests/SingleUseTransferTests.swift
@@ -0,0 +1,44 @@
+//
+//  SingleUseTransferTests.swift
+//  Principle
+//
+//  Created by Kamil Strzelecki on 28/04/2025.
+//  Copyright © 2025 Kamil Strzelecki. All rights reserved.
+//
+
+@testable import PrincipleConcurrency
+import Synchronization
+import Testing
+
+internal struct SingleUseTransferTests {
+
+    @Test
+    func testFinalize() {
+        let mutex = Mutex(NonSendable())
+        let instance = NonSendable()
+        var transfer = SingleUseTransfer(instance)
+
+        mutex.withLock { protected in
+            protected = transfer.finalize()
+        }
+    }
+
+    @Test
+    func testTake() async {
+        let instance = NonSendable()
+        var transfer = SingleUseTransfer(instance)
+
+        await withTaskGroup { group in
+            var transfer = transfer.take()
+            group.addTask {
+                _ = transfer.finalize()
+            }
+            await group.waitForAll()
+        }
+    }
+}
+
+extension SingleUseTransferTests {
+
+    private final class NonSendable {}
+}