Add tests for root.go

config/setup/root_test.go

+package setup
+
+import (
+	"fmt"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+)
+
+func TestRoot(t *testing.T) {
+
+	// Predefined error substrings
+	parseErrContent := "Parse error:"
+	unableToAccessErroContent := "Unable to access root path"
+
+	existingDirPath, err := getTempDirPath()
+	if err != nil {
+		t.Errorf("BeforeTest: Failed to find an existing directory for testing! Error was: %v", err)
+	}
+
+	nonExistingDir := filepath.Join(existingDirPath, "highly_unlikely_to_exist_dir")
+
+	existingFile, err := ioutil.TempFile("", "root_test")
+	if err != nil {
+		t.Errorf("BeforeTest: Failed to create temp file for testing! Error was: %v", err)
+	}
+	defer os.Remove(existingFile.Name())
+
+	unaccessiblePath := filepath.Join(existingFile.Name(), "some_name")
+
+	tests := []struct {
+		input              string
+		shouldErr          bool
+		expectedRoot       string // expected root, set to the controller. Empty for negative cases.
+		expectedErrContent string // substring from the expected error. Empty for positive cases.
+	}{
+		// positive
+		{
+			fmt.Sprintf(`root %s`, nonExistingDir), false, nonExistingDir, "",
+		},
+		{
+			fmt.Sprintf(`root %s`, existingDirPath), false, existingDirPath, "",
+		},
+		// negative
+		{
+			`root `, true, "", parseErrContent,
+		},
+		{
+			fmt.Sprintf(`root %s`, unaccessiblePath), true, "", unableToAccessErroContent,
+		},
+		{
+			fmt.Sprintf(`root {
+				%s
+			}`, existingDirPath), true, "", parseErrContent,
+		},
+	}
+
+	for i, test := range tests {
+		c := NewTestController(test.input)
+		mid, err := Root(c)
+		if test.shouldErr && err == nil {
+			t.Errorf("Test %d: Expected error but found nil for input %s", i, test.input)
+		}
+
+		if err != nil {
+			if !test.shouldErr {
+				t.Errorf("Test %d: Expected no error but found one for input %s. Error was: %v", i, test.input, err)
+			}
+
+			if !strings.Contains(err.Error(), test.expectedErrContent) {
+				t.Errorf("Test %d: Expected error to contain: %v, found error: %v, input: %s", i, test.expectedErrContent, err, test.input)
+			}
+		}
+
+		// the Root method always returns a nil middleware
+		if mid != nil {
+			t.Errorf("Middware, returned from Root() was not nil: %v", mid)
+		}
+
+		// check c.Root only if we are in a positive test.
+		if !test.shouldErr && test.expectedRoot != c.Root {
+			t.Errorf("Root not correctly set for input %s. Expected: %s, actual: %s", test.input, test.expectedRoot, c.Root)
+		}
+	}
+}
+
+// getTempDirPath returnes the path to the system temp directory. If it does not exists - an error is returned.
+func getTempDirPath() (string, error) {
+	tempDir := os.TempDir()
+
+	_, err := os.Stat(tempDir)
+	if err != nil {
+		return "", err
+	}
+
+	return tempDir, nil
+}