ci: add action to validate source strings, excluding escaped characters

Author: jesmrec

.github/workflows/validate-source-strings.yml

@@ -0,0 +1,63 @@
+name: Validate Android source strings
+
+on:
+  push:
+
+permissions:
+  contents: read
+
+jobs:
+  validate-strings:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v5
+
+      - name: Install xmlstarlet
+        run: sudo apt-get update && sudo apt-get install -y xmlstarlet
+
+      - name: Validate source strings
+        shell: bash
+        run: |
+          xml_file="owncloudApp/src/main/res/values/strings.xml"
+          has_errors=0
+
+          # ANSI-C quoting to read characters correctly
+          forbidden_values=($'\'' $'"' $'@' $'\n' $'\t')
+          escaped_values=($'\\\'' $'\\"' $'\\@' $'\\n' $'\\t')
+
+          # Read one line every iteration
+          while IFS= read -r line; do
+
+            # Takes everything on the left of ^^
+            string_name="${line%%^^*}"
+            # Takes everything on the right of ^^
+            string_value="${line#*^^}"
+
+            # Check if the string contains any of the escaped_values and remove it
+            for escaped in "${escaped_values[@]}"; do
+              string_value="${string_value//"$escaped"/}"
+            done
+
+            # Check if the string contains any of the forbidden_values
+            for forbidden in "${forbidden_values[@]}"; do
+              if [[ "$string_value" == *"$forbidden"* ]]; then
+                echo "Source string \"$string_name\" contains forbidden characters"
+                has_errors=1
+                break
+              fi
+            done
+          # Read the input file line by line
+          done < <(
+            xmlstarlet sel \
+              -t \
+              -m '/resources/string' \
+              -v '@name' \
+              -o '^^' \
+              -v '.' \
+              -n \
+              "$xml_file"
+          )
+
+          exit $has_errors