add test

case_test.go

@@ -0,0 +1,34 @@
+package sqlingo
+
+import (
+	"errors"
+	"testing"
+)
+
+func TestCase(t *testing.T) {
+	c1 := expression{
+		builder: func(scope scope) (string, error) {
+			return "c1", nil
+		},
+	}
+	c2 := expression{
+		builder: func(scope scope) (string, error) {
+			return "c2", nil
+		},
+	}
+	assertValue(t, Case().WhenThen(c1, 1).WhenThen(c2, 2),
+		"CASE WHEN c1 THEN 1 WHEN c2 THEN 2 END")
+	assertValue(t, Case().WhenThen(c1, 1).WhenThen(c2, 2).Else(0),
+		"CASE WHEN c1 THEN 1 WHEN c2 THEN 2 ELSE 0 END")
+	assertValue(t, Case().Else(0),
+		"0")
+
+	ee := expression{
+		builder: func(scope scope) (string, error) {
+			return "", errors.New("error")
+		},
+	}
+	assertError(t, Case().WhenThen(ee, 2))
+	assertError(t, Case().WhenThen(c1, ee))
+	assertError(t, Case().WhenThen(c1, 1).Else(ee))
+}