fix: match CI to Swift 6.4 and the Xcode 27 runner

.github/workflows/ci.yml

@@ -1,45 +1,39 @@
 name: ci
 
-# macos-latest is the macOS 26 image. It does not install Xcode 16.4, and the
-# simulator-discovery script previously used here failed on that image
-# (https://github.com/fulldecent/FDWaveformView/actions/runs/25414955912).
-# This job pins the macOS 15 image, whose default Xcode is 16.4 and which
-# lists an iPhone 16 simulator on iOS 18.5:
-# https://github.com/actions/runner-images/blob/main/images/macos/macos-15-arm64-Readme.md
+# GitHub-hosted Xcode 27. macos-26 stops at Xcode 26, which cannot load
+# swift-tools-version 6.4.
+# https://github.blog/changelog/2026-07-16-xcode-27-runner-image-now-in-public-preview/
+# https://github.com/actions/runner-images/blob/main/images/macos/xcode-27-arm64-Readme.md
+#
+# swift6-module-template runs `xcrun swift test` on this runner. This package
+# imports UIKit and its platforms are iOS and visionOS, so that command builds
+# for macOS and cannot compile. The destination below is the iPhone 17
+# simulator on iOS 27.0, which the Xcode 27.0 image lists.
+#
+# release.yml calls this workflow. It reads $.jobs.build-test.
 
 on:
+  workflow_call:
   push:
-    branches:
-      - main
   pull_request:
 
 concurrency:
   group: ci-${{ github.workflow }}-${{ github.ref }}
   cancel-in-progress: true
 
 jobs:
-  test:
-    name: Build and Test
-    runs-on: macos-15
-
+  build-test:
+    name: Build and test
+    runs-on: xcode-27
     steps:
-      - name: Check out repository
-        uses: actions/checkout@v4
-
-      - name: Select Xcode
-        run: sudo xcode-select -s /Applications/Xcode_16.4.app
+      - name: Check out this commit
+        uses: actions/checkout@v7
 
       - name: Show build environment
         run: |
           xcodebuild -version
           xcrun swift --version
 
-      - name: Build
-        run: |
-          xcodebuild build \
-            -scheme FDWaveformView \
-            -destination 'platform=iOS Simulator,name=iPhone 16,OS=18.5'
-
       - name: Check formatting
         run: |
           swift format format --in-place --recursive Sources/ Tests/
@@ -49,4 +43,4 @@ jobs:
         run: |
           xcodebuild test \
             -scheme FDWaveformView \
-            -destination 'platform=iOS Simulator,name=iPhone 16,OS=18.5'
+            -destination 'platform=iOS Simulator,name=iPhone 17,OS=27.0'

.github/workflows/release.yml

@@ -0,0 +1,122 @@
+# Release
+#
+# Open or update the release pull request, test the package, and publish the
+# GitHub Release.
+#
+# Adapted from swift6-module-template release 16.5.0:
+# https://github.com/fulldecent/swift6-module-template/blob/v16.5.0/.github/workflows/release.yml
+# That workflow attests a Linux static library from `swift build -c release`.
+# This package imports UIKit, so there is no Linux library to publish. Swift
+# Package Manager installs from the git tag. The published release is the tag
+# and the generated notes.
+#
+# Tags stay `5.1.1`, without a `v` prefix, because that is the shape of the
+# existing tags. release-please-config.json sets include-v-in-tag to false.
+#
+# One-time setup
+#   1. GitHub repo > Settings > General > Releases > Enable release immutability.
+#   2. GitHub repo > Settings > Actions > General > Workflow permissions: Read and write permissions.
+#   3. Under Workflow permissions, check "Allow GitHub Actions to create and approve pull requests".
+
+name: Release
+
+on:
+  push:
+    branches: ["main"]
+  workflow_dispatch:
+    inputs:
+      tag:
+        description: Tag to publish, for example 5.1.2. Leave empty to open or update the release pull request only.
+        required: false
+        type: string
+
+permissions:
+  contents: write
+  issues: write
+  pull-requests: write
+
+jobs:
+  propose:
+    name: Open or update the release pull request
+    if: github.event_name == 'push' || inputs.tag == ''
+    runs-on: ubuntu-latest
+    outputs:
+      pr: ${{ steps.merged.outputs.pr }}
+      tag_name: ${{ steps.merged.outputs.tag_name }}
+    steps:
+      - name: Open the release pull request
+        uses: googleapis/release-please-action@v5
+        with:
+          config-file: release-please-config.json
+          manifest-file: .release-please-manifest.json
+          skip-github-release: true
+
+      - name: Find a merged release pull request
+        id: merged
+        if: github.event_name == 'push'
+        env:
+          GH_TOKEN: ${{ github.token }}
+        run: |
+          found=$(gh api "repos/$GITHUB_REPOSITORY/commits/$GITHUB_SHA/pulls" --jq '
+            .[] | select(.merged_at != null and any(.labels[]; .name == "autorelease: pending"))
+            | "\(.number) \(.title | capture("release (?<v>[0-9]+[.][0-9]+[.][0-9]+)").v)"' | head -n 1)
+          if [ -n "$found" ]; then
+            read -r pr tag <<< "$found"
+            echo "pr=$pr" >> "$GITHUB_OUTPUT"
+            echo "tag_name=$tag" >> "$GITHUB_OUTPUT"
+          fi
+
+  build-test:
+    name: Build and test
+    needs: propose
+    if: |
+      always() &&
+      (needs.propose.result == 'success' || needs.propose.result == 'skipped') &&
+      (needs.propose.outputs.tag_name != '' ||
+       (github.event_name == 'workflow_dispatch' && inputs.tag != ''))
+    uses: ./.github/workflows/ci.yml
+
+  publish:
+    name: Publish release
+    needs: [propose, build-test]
+    if: |
+      always() &&
+      needs.build-test.result == 'success' &&
+      (needs.propose.outputs.tag_name != '' ||
+       (github.event_name == 'workflow_dispatch' && inputs.tag != ''))
+    runs-on: ubuntu-latest
+    permissions:
+      contents: write
+      pull-requests: write
+    steps:
+      - name: Resolve the tag
+        id: tag
+        env:
+          TAG: ${{ inputs.tag || needs.propose.outputs.tag_name }}
+        run: |
+          case "$TAG" in
+            [0-9]*.[0-9]*.[0-9]*) ;;
+            *) echo "tag must look like 5.1.2" >&2; exit 1 ;;
+          esac
+          echo "tag=$TAG" >> "$GITHUB_OUTPUT"
+
+      - name: Publish
+        env:
+          GH_TOKEN: ${{ github.token }}
+          TAG: ${{ steps.tag.outputs.tag }}
+        run: |
+          gh release create "$TAG" \
+            --repo "$GITHUB_REPOSITORY" \
+            --target "$GITHUB_SHA" \
+            --title "$TAG" \
+            --generate-notes \
+            --latest
+
+      - name: Mark the release pull request tagged
+        if: needs.propose.outputs.pr != ''
+        env:
+          GH_TOKEN: ${{ github.token }}
+          PR: ${{ needs.propose.outputs.pr }}
+        run: |
+          gh api -X DELETE "repos/$GITHUB_REPOSITORY/issues/$PR/labels/autorelease:%20pending"
+          gh api "repos/$GITHUB_REPOSITORY/issues/$PR/labels" -f "labels[]=autorelease: tagged"

.release-please-manifest.json

@@ -0,0 +1,3 @@
+{
+  ".": "5.1.1"
+}

CHANGELOG.md

@@ -9,9 +9,10 @@ All notable changes to this project will be documented in this file.
 
 ### Changed
 
-- Pin GitHub Actions to the macOS 15 image, Xcode 16.4, and an iPhone 16 simulator on iOS 18.5. The workflow on `macos-latest` failed before the package compiled.
+- Require Swift tools 6.4 and enable Approachable Concurrency. Xcode 26 cannot load that tools version.
+- Test on the GitHub-hosted Xcode 27 runner, using an iPhone 17 simulator on iOS 27.0.
+- Hand releases to Release Please. Commit messages use `fix:`, `feat:` or `BREAKING CHANGE:`. Tags stay unprefixed, matching `5.1.1`.
 - Inline `.gitignore` from the current Swift and Xcode ignore files, plus the macOS and secret rules from project-template.
-- Describe the release steps in terms of `CHANGELOG.md` and a GitHub tag.
 
 ---
 

CONTRIBUTING.md

@@ -1,27 +1,16 @@
 # Contributing
 
-All contributors are welcome. Please use issues and pull requests to contribute to the project. And update [CHANGELOG.md](CHANGELOG.md) when committing.
+All contributors are welcome. Please use issues and pull requests to contribute to the project. Commit messages use `fix:`, `feat:` or `BREAKING CHANGE:`. Release Please writes [CHANGELOG.md](CHANGELOG.md) from those messages.
 
 ## Release process
 
-1. Confirm the build is [passing in GitHub Actions](https://github.com/fulldecent/FDWaveformView/actions)
-2. Push a release commit
-   1. Create a new Main section at the top of [CHANGELOG.md](CHANGELOG.md)
-   2. Rename the old Main section like:
+Merging the release pull request tags the release and publishes the GitHub Release. The settings that pull request needs are in [Releases](README.md#releases). Confirm the build is [passing in GitHub Actions](https://github.com/fulldecent/FDWaveformView/actions) before merging it.
 
-      ```markdown
-      ## [5.1.1](https://github.com/fulldecent/FDWaveformView/releases/tag/5.1.1)
-
-      Released on 2025-12-06.
-      ```
-
-3. Create a GitHub release
-   1. Tag the release (like `5.1.1`)
-   2. Paste notes from [CHANGELOG.md](CHANGELOG.md)
+Tags stay `5.1.1`, without a `v` prefix. That matches the tags already on this repository. [release-please-config.json](release-please-config.json) sets `include-v-in-tag` to false so Release Please finds tag `5.1.1`.
 
 ## Maintenance
 
 Do this every quarter or so.
 
-1. Review the Xcode pin in [.github/workflows/ci.yml](.github/workflows/ci.yml). The job uses the `macos-15` runner and `/Applications/Xcode_16.4.app`, then tests on an iPhone 16 simulator running iOS 18.5. Those are the versions listed for that image in the [macOS 15 runner readme](https://github.com/actions/runner-images/blob/main/images/macos/macos-15-arm64-Readme.md). `macos-latest` is the macOS 26 image and does not install Xcode 16.4, so a workflow that selects `macos-latest` and then looks up a simulator will fail before it compiles this package.
-2. Review [actions/checkout](https://github.com/actions/checkout) and move the `uses:` pin forward when a new major version is safe. The workflow currently uses `actions/checkout@v4`.
+1. Review the Swift tools version in [Package.swift](Package.swift) and the runner in [.github/workflows/ci.yml](.github/workflows/ci.yml). The job uses the GitHub-hosted `xcode-27` image because a Swift tools version of 6.4 does not load on Xcode 26. The test destination is an iPhone 17 simulator on iOS 27.0, which that image lists for Xcode 27.0. `xcrun swift test` builds this package for macOS, and the sources import UIKit, so the workflow uses `xcodebuild` instead. The image contents are in the [Xcode 27 runner readme](https://github.com/actions/runner-images/blob/main/images/macos/xcode-27-arm64-Readme.md).
+2. Review external actions in [.github/workflows](.github/workflows). The workflow currently uses `actions/checkout@v7` and `googleapis/release-please-action@v5`.

Package.swift

@@ -1,4 +1,4 @@
-// swift-tools-version: 5.10
+// swift-tools-version: 6.4
 // The swift-tools-version declares the minimum version of Swift required to build this package.
 
 import PackageDescription
@@ -19,9 +19,17 @@ let package = Package(
     // Targets are the basic building blocks of a package, defining a module or a test suite.
     // Targets can depend on other targets in this package and products from dependencies.
     .target(
-      name: "FDWaveformView"),
+      name: "FDWaveformView",
+      swiftSettings: [
+        .enableUpcomingFeature("ApproachableConcurrency")
+      ]
+    ),
     .testTarget(
       name: "FDWaveformViewTests",
-      dependencies: ["FDWaveformView"]),
+      dependencies: ["FDWaveformView"],
+      swiftSettings: [
+        .enableUpcomingFeature("ApproachableConcurrency")
+      ]
+    ),
   ]
 )

README.md

@@ -69,7 +69,7 @@ UIView.animate(withDuration: 0.3) {
 
 - Antialiased waveforms draw extra pixels to avoid jagged edges.
 - Autolayout-driven size changes trigger re-rendering to prevent pixelation.
-- Supports iOS 15+, visionOS 1+, and Swift tools version 5.10, as declared in `Package.swift`.
+- Supports iOS 15+, visionOS 1+, and Swift tools version 6.4, as declared in `Package.swift`. Xcode 26 cannot load that tools version.
 - Includes unit tests that run on GitHub Actions.
 
 ## Installation
@@ -110,12 +110,14 @@ A couple other things are exposed that we do not consider public API:
 
 ## Testing
 
-GitHub Actions runs the suite on the macOS 15 image with Xcode 16.4. That image provides an iPhone 16 simulator on iOS 18.5. The command is:
+GitHub Actions runs the suite on the [Xcode 27 runner image](https://github.com/actions/runner-images/blob/main/images/macos/xcode-27-arm64-Readme.md). The default Xcode there is 27.0, and that copy provides an iPhone 17 simulator on iOS 27.0. The command is:
 
 ```sh
-xcodebuild test -scheme FDWaveformView -destination 'platform=iOS Simulator,name=iPhone 16,OS=18.5'
+xcodebuild test -scheme FDWaveformView -destination 'platform=iOS Simulator,name=iPhone 17,OS=27.0'
 ```
 
+`xcrun swift test` builds the package for macOS. These sources import UIKit, so that command does not compile this package.
+
 On another Xcode, list the simulators that copy of Xcode can see and pass one of those ids. `xcodebuild` only accepts destinations from the selected Xcode, so an id printed by a different install will fail.
 
 ```sh
@@ -129,7 +131,16 @@ The Example app target deploys to iOS 18.6, so its simulator has to be iOS 18.6
 xcodebuild build -project Example/Example.xcodeproj -scheme Example -destination 'id=XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX'
 ```
 
+## Releases
+
+Commit messages use `fix:`, `feat:` or `BREAKING CHANGE:`. [Release Please](https://github.com/googleapis/release-please) opens a release pull request from those messages. Merging that pull request runs [.github/workflows/release.yml](.github/workflows/release.yml), which tests the package and publishes the GitHub Release.
+
+[`.release-please-manifest.json`](.release-please-manifest.json) is the last released version, `5.1.1`. Tags do not use a `v` prefix, because the existing tags do not. Swift Package Manager installs from the git tag. This module imports UIKit, so the release does not attach a Linux static library.
+
+In the repository settings, under Actions, General, Workflow permissions, select read and write permissions and check "Allow GitHub Actions to create and approve pull requests". Under General, Releases, enable release immutability.
+
 ## Contributing
 
 - This project's layout is based on <https://github.com/fulldecent/swift6-module-template>
 - Ignore rules are inlined from [Swift.gitignore](https://github.com/github/gitignore/blob/main/Swift.gitignore) and [Global/Xcode.gitignore](https://github.com/github/gitignore/blob/main/Global/Xcode.gitignore). The macOS and secret rules above them come from [project-template](https://github.com/fulldecent/project-template).
+- Releases follow [swift6-module-template](https://github.com/fulldecent/swift6-module-template/blob/v16.5.0/.github/workflows/release.yml), release 16.5.0. The published result here is the git tag. That template publishes a Linux static library, and this module imports UIKit.

release-please-config.json

@@ -0,0 +1,9 @@
+{
+  "$schema": "https://raw.githubusercontent.com/googleapis/release-please/main/schemas/config.json",
+  "release-type": "simple",
+  "include-component-in-tag": false,
+  "include-v-in-tag": false,
+  "packages": {
+    ".": {}
+  }
+}