stacktrace and errors test

Signed-off-by: Bisakh Mondal <bisakhmondal00@gmail.com>

pkg/errors/errors_test.go

@@ -0,0 +1,139 @@
+package errors
+
+import (
+	stderrors "errors"
+	"fmt"
+	"regexp"
+	"strconv"
+	"testing"
+
+	"github.com/thanos-io/thanos/pkg/testutil"
+)
+
+const msg = "test_error_message"
+const wrapper = "test_wrapper"
+
+func TestNew(t *testing.T) {
+	err := New(msg)
+	testutil.Equals(t, err.Error(), msg, "the root error message must match")
+
+	reg := regexp.MustCompile(msg + `[ \n]+> github\.com\/thanos-io\/thanos\/pkg\/errors\.TestNew	.*\/thanos\/pkg\/errors\/errors_test\.go:17`)
+	testutil.Equals(t, reg.MatchString(fmt.Sprintf("%+v", err)), true, "the stack trace must match")
+}
+
+func TestNewFormatted(t *testing.T) {
+	fmtMsg := msg + " key=%v"
+	expectedMsg := msg + " key=value"
+
+	err := New(fmtMsg, "value")
+	testutil.Equals(t, err.Error(), expectedMsg, "the root error message must match")
+	reg := regexp.MustCompile(expectedMsg + `[ \n]+> github\.com\/thanos-io\/thanos\/pkg\/errors\.TestNewFormatted	.*\/thanos\/pkg\/errors\/errors_test\.go:28`)
+	testutil.Equals(t, reg.MatchString(fmt.Sprintf("%+v", err)), true, "the stack trace must match")
+}
+
+func TestWrap(t *testing.T) {
+	err := New(msg)
+	err = Wrap(err, wrapper)
+
+	expectedMsg := wrapper + ": " + msg
+	testutil.Equals(t, err.Error(), expectedMsg, "the root error message must match")
+
+	reg := regexp.MustCompile(`test_wrapper[ \n]+> github\.com\/thanos-io\/thanos\/pkg\/errors\.TestWrap	.*\/thanos\/pkg\/errors\/errors_test\.go:36
+[[:ascii:]]+test_error_message[ \n]+> github\.com\/thanos-io\/thanos\/pkg\/errors\.TestWrap	.*\/thanos\/pkg\/errors\/errors_test\.go:35`)
+
+	testutil.Equals(t, reg.MatchString(fmt.Sprintf("%+v", err)), true, "the stack trace must match")
+}
+
+func TestUnwrap(t *testing.T) {
+	// test with base error
+	err := New(msg)
+
+	for i, tc := range []struct {
+		err      error
+		expected string
+		isNil    bool
+	}{
+		{
+			// no wrapping
+			err:   err,
+			isNil: true,
+		},
+		{
+			err:      Wrap(err, wrapper),
+			expected: "test_error_message",
+		},
+		{
+			err:      Wrap(Wrap(err, wrapper), wrapper),
+			expected: "test_wrapper: test_error_message",
+		},
+		// check primitives errors
+		{
+			err:   stderrors.New("std-error"),
+			isNil: true,
+		},
+		{
+			err:      Wrap(stderrors.New("std-error"), wrapper),
+			expected: "std-error",
+		},
+		{
+			err:   nil,
+			isNil: true,
+		},
+	} {
+		t.Run("TestCase"+strconv.Itoa(i), func(t *testing.T) {
+			unwrapped := Unwrap(tc.err)
+			if tc.isNil {
+				testutil.Equals(t, unwrapped, nil)
+				return
+			}
+			testutil.Equals(t, unwrapped.Error(), tc.expected, "Unwrap must match expected output")
+		})
+	}
+}
+
+func TestCause(t *testing.T) {
+	// test with base error that implements interface containing Unwrap method
+	err := New(msg)
+
+	for i, tc := range []struct {
+		err      error
+		expected string
+		isNil    bool
+	}{
+		{
+			// no wrapping
+			err:   err,
+			isNil: true,
+		},
+		{
+			err:   Wrap(err, wrapper),
+			isNil: true,
+		},
+		{
+			err:   Wrap(Wrap(err, wrapper), wrapper),
+			isNil: true,
+		},
+		// check primitives errors
+		{
+			err:      stderrors.New("std-error"),
+			expected: "std-error",
+		},
+		{
+			err:      Wrap(stderrors.New("std-error"), wrapper),
+			expected: "std-error",
+		},
+		{
+			err:   nil,
+			isNil: true,
+		},
+	} {
+		t.Run("TestCase"+strconv.Itoa(i), func(t *testing.T) {
+			cause := Cause(tc.err)
+			if tc.isNil {
+				testutil.Equals(t, cause, nil)
+				return
+			}
+			testutil.Equals(t, cause.Error(), tc.expected, "Unwrap must match expected output")
+		})
+	}
+}

pkg/errors/stacktrace_test.go

@@ -0,0 +1,27 @@
+package errors
+
+import (
+	"strings"
+	"testing"
+)
+
+func caller() stacktrace {
+	return newStackTrace()
+}
+
+func TestStacktraceOutput(t *testing.T) {
+	st := caller()
+	expectedPhrase := "thanos/pkg/errors/stacktrace_test.go:13"
+	if !strings.Contains(st.String(), expectedPhrase) {
+		t.Fatalf("expected %v phrase into the stacktrace, received stacktrace: \n%v", expectedPhrase, st.String())
+	}
+}
+
+func TestStacktraceProgramCounterLen(t *testing.T) {
+	st := caller()
+	output := st.String()
+	lines := len(strings.Split(strings.TrimSuffix(output, "\n"), "\n"))
+	if len(st) != lines {
+		t.Fatalf("output lines vs program counter size mismatch: program counter size %v, output lines %v", len(st), lines)
+	}
+}