test: testing panics and empty input

.github/workflows/ci.yml

@@ -3,24 +3,6 @@ name: CI
 on: [push, pull_request]
 
 jobs:
-  build-test:
-    name: Build test
-    runs-on: ${{ matrix.os }}
-    strategy:
-      matrix:
-        os: [ubuntu-latest, macos-latest, windows-latest]
-        go-version: [1.16.x, 1.17.x]
-    steps:
-      - name: Checkout code
-        uses: actions/checkout@v2
-
-      - name: Install Go
-        uses: actions/setup-go@v2
-        with:
-          go-version: ${{ matrix.go-version }}
-
-      - name: Build
-        run: go build ./
   coverage:
     name: Coverage
     runs-on: ubuntu-latest

asciitxt.go

@@ -32,6 +32,10 @@ func WithConfig(txt string, config Config) string {
 		config.Style = StyleStandard
 	}
 
+	if txt == "" {
+		return ""
+	}
+
 	letters := strings.Split(txt, "")
 	var arr [][]string
 	llen := getStyleLength(config.Style)

asciitxt_test.go

@@ -20,3 +20,24 @@ func TestWithConfig(t *testing.T) {
 		t.Error("should not be empty")
 	}
 }
+
+func TestEmpty(t *testing.T) {
+	s := asciitxt.New("")
+	if s != "" {
+		t.Error("should be empty, got:", s)
+	}
+}
+
+func TestInvalidStyle(t *testing.T) {
+	// this should panic
+	assertPanic(t, func() { asciitxt.WithConfig("hello", asciitxt.Config{Style: 2}) })
+}
+
+func assertPanic(t *testing.T, f func()) {
+	defer func() {
+		if r := recover(); r == nil {
+			t.Errorf("The code did not panic")
+		}
+	}()
+	f()
+}