ci: add tasks for validating themes

.github/scripts/theme-uniqueness.sh

@@ -0,0 +1,40 @@
+#!/usr/bin/env bash
+
+# hidden folders are skipped in this
+for dir1 in *; do
+    # skip files
+    if [[ -f "$dir1" ]]; then
+        continue
+    fi
+
+    for dir2 in *; do
+        # skip files
+        if [[ -f "$dir2" ]]; then
+            continue
+        fi
+        
+        # skip comparison between the theme and itself
+        if [[ "$dir1" != "$dir2" ]]; then
+            css1="$dir1/user.css" 
+            css2="$dir2/user.css" 
+
+            if [ ! -e "$css1" -a ! -e "$css2" ]; then 
+                echo "Found duplicate themes: $dir1 and $dir2"
+                echo "Both have no user.css"
+                exit 1
+            # check if user.css does not exist in one of the 2 themes
+            elif [ ! -e "$css1" -o ! -e "$css2" ]; then 
+                continue
+            fi
+
+            # compare color css and check if there are no differences apart
+            # from whitespace
+            diffs=$(diff -b "$css1" "$css2")
+            
+            if [[ -z "$diffs" ]]; then
+                echo "Found duplicate themes: $dir1 and $dir2"
+                exit 1
+            fi
+        fi
+    done
+done

.github/scripts/themes-name-matcher.sh

@@ -0,0 +1,11 @@
+#!/usr/bin/env bash
+
+invalid_themes=$(find . -maxdepth 1 -type d \
+    ! -regex "./\..*" \
+    ! -regex "\." \
+    ! -regex "\./[A-Z][a-z0-9]*\(-?[A-Z][a-z0-9]*\)*")
+
+if [[ ! -z "$invalid_themes" ]]; then
+    echo "Invalid theme names: $invalid_themes"
+    exit 1
+fi

.github/workflows/validate-themes-name.yml

@@ -0,0 +1,9 @@
+name: validate-themes-name
+on: [push, pull_request]
+jobs:
+  validate-themes-name:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - run: .github/scripts/themes-name-matcher.sh
+      

.github/workflows/verify-theme-uniqueness.yml

@@ -0,0 +1,9 @@
+name: verify-themes-uniqueness
+on: [push, pull_request]
+jobs:
+  verify-theme-uniqueness:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - run: ./.github/scripts/theme-uniqueness.sh
+