simplify setup() function in tests

- change the current directory in the function
- do not mix `t.Fatal` and `panic`

zglob_test.go

@@ -59,11 +59,9 @@ func fatalIf(err error) {
 	}
 }
 
-func setup(t *testing.T) string {
+func setup() (string, string) {
 	tmpdir, err := ioutil.TempDir("", "zglob")
-	if err != nil {
-		t.Fatal(err)
-	}
+	fatalIf(err)
 
 	fatalIf(os.MkdirAll(filepath.Join(tmpdir, "foo/baz"), 0755))
 	fatalIf(os.MkdirAll(filepath.Join(tmpdir, "foo/bar"), 0755))
@@ -78,22 +76,17 @@ func setup(t *testing.T) string {
 	fatalIf(os.MkdirAll(filepath.Join(tmpdir, "zzz/nar/{noo,x}"), 0755))
 	fatalIf(ioutil.WriteFile(filepath.Join(tmpdir, "zzz/nar/{noo,x}/joo.png"), []byte{}, 0644))
 
-	return tmpdir
+	curdir, err := os.Getwd()
+	fatalIf(err)
+	fatalIf(os.Chdir(tmpdir))
+
+	return tmpdir, curdir
 }
 
 func TestGlob(t *testing.T) {
-	tmpdir := setup(t)
+	tmpdir, savedCwd := setup()
 	defer os.RemoveAll(tmpdir)
-
-	curdir, err := os.Getwd()
-	if err != nil {
-		t.Fatal(err)
-	}
-	err = os.Chdir(tmpdir)
-	if err != nil {
-		t.Fatal(err)
-	}
-	defer os.Chdir(curdir)
+	defer os.Chdir(savedCwd)
 
 	tmpdir = "."
 	for _, test := range testGlobs {
@@ -115,18 +108,9 @@ func TestGlob(t *testing.T) {
 }
 
 func TestGlobAbs(t *testing.T) {
-	tmpdir := setup(t)
+	tmpdir, savedCwd := setup()
 	defer os.RemoveAll(tmpdir)
-
-	curdir, err := os.Getwd()
-	if err != nil {
-		t.Fatal(err)
-	}
-	err = os.Chdir(tmpdir)
-	if err != nil {
-		t.Fatal(err)
-	}
-	defer os.Chdir(curdir)
+	defer os.Chdir(savedCwd)
 
 	for _, test := range testGlobs {
 		pattern := toSlash(path.Join(tmpdir, test.pattern))