Add Formatting To CI/CD

Signed-off-by: Will Hawkins <hawkinsw@obs.cr>

.github/workflows/main.yaml

@@ -36,3 +36,17 @@ jobs:
         working-directory: ./tree-sitter-p4
       - run: swift build
       - run: swift test
+  library-format-tests:
+    name: Library Format Tests
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - uses: actions/setup-node@v4
+      - uses: tree-sitter/setup-action@v2
+      - uses: swift-actions/setup-swift@v2
+        with:
+          swift-version: "6.2"
+      - run: tree-sitter generate
+        working-directory: ./tree-sitter-p4
+      - run: ./ci/format.sh
+

README.md

@@ -33,5 +33,5 @@ For more information, see the [documentation for the Swift-DocC plugin](https://
 To check the format:
 
 ```console
-$ swift package plugin --allow-writing-to-package-directory swiftformat
+$ swift-format --recursive -i Sources/
 ```

ci/format.sh

@@ -0,0 +1,13 @@
+#!/bin/bash
+
+# Format
+swift format --recursive -i Sources/ 2>&1 >/dev/null
+
+# Modified count
+mc=`git status . | grep modified | wc -l | sed 's/ //g'`
+
+if [ ${mc} -ne 0 ]; then
+    exit 1
+fi
+
+exit 0