ci: add scripts to validate that public API has not changed

.github/workflows/ci.yaml

@@ -9,6 +9,13 @@ on:
       - 'main'
 
 jobs:
+  API-diff:
+    runs-on: macOS-latest
+    steps:
+    - uses: actions/checkout@v3
+    - name: Run public API diff
+      run: scripts/api_diff.sh
+
   Tests:
     runs-on: macOS-latest
     steps:

.gitignore

@@ -8,4 +8,5 @@ DerivedData/
 .netrc
 .build
 .mockingbird
-project.json
+project.json
+scripts/raw_api.json

scripts/api_diff.sh

@@ -0,0 +1,19 @@
+#!/bin/bash
+
+set -e
+
+script_dir=$(dirname $0)
+root_dir="$script_dir/../"
+
+# Generate the json file with:
+sourcekitten doc --module-name Confidence -- -scheme Confidence-Package -destination 'platform=iOS Simulator,name=iPhone 15,OS=17.2' > $script_dir/raw_api.json
+
+# Extract the public API from the raw api json file
+python3 $script_dir/extract_public_funcs.py $script_dir/raw_api.json $script_dir/current_public_api.json
+
+# Clean up the raw api json file
+rm $script_dir/raw_api.json
+
+# Compare the public API with the previous public API and exit with 1 if there are changes
+# TODO(nicklasl): store the result (exit code) and provide information on how to remedy.
+git diff --no-index --exit-code $script_dir/public_api.json $script_dir/current_public_api.json