test: improve test coverage (#83)

VERSION

@@ -1 +1 @@
-0.0.12
+0.0.13

test/pattern.go

@@ -8,6 +8,9 @@ import (
 	"github.com/stretchr/testify/require"
 )
 
+// errExit is an error instance for comparing to the exit code error.
+var errExit = &exec.ExitError{}
+
 // MainParams provides the test parameters for testing a `main`-method.
 type MainParams struct {
 	Args     []string
@@ -56,10 +59,10 @@ func TestMain(main func()) func(t Test, param MainParams) {
 		cmd := exec.Command(os.Args[0], "-test.run="+t.(*Tester).t.Name())
 		cmd.Env = append(append(os.Environ(), "TEST="+t.Name()), param.Env...)
 		if err := cmd.Run(); err != nil || param.ExitCode != 0 {
-			errExit := &exec.ExitError{}
-			if errors.As(err, &errExit) {
+			if errors.As(err, &errExit) || err != nil {
 				require.Equal(t, param.ExitCode, errExit.ExitCode())
 			} else {
+				// #no-cover: impossible to reach this code.
 				require.Fail(t, "unexpected error", err)
 			}
 		}

test/pattern_test.go

@@ -0,0 +1,31 @@
+package test_test
+
+import (
+	"os"
+	"strconv"
+	"testing"
+
+	"github.com/tkrop/go-testing/test"
+)
+
+var testMainParams = map[string]test.MainParams{
+	"exit-0": {},
+	"exit-1": {
+		Env:      []string{"exit=1"},
+		ExitCode: 1,
+	},
+}
+
+func TestMain(t *testing.T) {
+	test.Map(t, testMainParams).Run(test.TestMain(main))
+}
+
+func TestMainUnexpected(t *testing.T) {
+	t.Setenv("TEST", "other")
+	test.Map(t, testMainParams).RunSeq(test.TestMain(main))
+}
+
+func main() {
+	exit, _ := strconv.Atoi(os.Getenv("exit"))
+	os.Exit(exit)
+}