github.com/stretchr/testify - main desired update. Old version has bugs.

github.com/davecgh/go-spew/spew is set to the newest version, a bit
newer than required by testify. Updated from version 6 Nov 2015 to
27 Jun 2017.

github.com/stretchr/objx is not updated - testify uses version
from 27 May 2014 which is older than 28 Sep 2015 used now (latest
actually). In practice there is only a tiny difference - one method was
removed in new version.

vendor/github.com/stretchr/testify/assert/assertions.go

@@ -4,6 +4,7 @@ import (
 	"bufio"
 	"bytes"
 	"encoding/json"
+	"errors"
 	"fmt"
 	"math"
 	"reflect"
@@ -18,6 +19,8 @@ import (
 	"github.com/pmezard/go-difflib/difflib"
 )
 
+//go:generate go run ../_codegen/main.go -output-package=assert -template=assertion_format.go.tmpl
+
 // TestingT is an interface wrapper around *testing.T
 type TestingT interface {
 	Errorf(format string, args ...interface{})
@@ -38,7 +41,15 @@ func ObjectsAreEqual(expected, actual interface{}) bool {
 	if expected == nil || actual == nil {
 		return expected == actual
 	}
-
+	if exp, ok := expected.([]byte); ok {
+		act, ok := actual.([]byte)
+		if !ok {
+			return false
+		} else if exp == nil || act == nil {
+			return exp == nil && act == nil
+		}
+		return bytes.Equal(exp, act)
+	}
 	return reflect.DeepEqual(expected, actual)
 
 }
@@ -65,7 +76,7 @@ func ObjectsAreEqualValues(expected, actual interface{}) bool {
 
 /* CallerInfo is necessary because the assert functions use the testing object
 internally, causing it to print the file:line of the assert method, rather than where
-the problem actually occured in calling code.*/
+the problem actually occurred in calling code.*/
 
 // CallerInfo returns an array of strings containing the file and line number
 // of each stack frame leading from the current test to the assert call that
@@ -82,7 +93,9 @@ func CallerInfo() []string {
 	for i := 0; ; i++ {
 		pc, file, line, ok = runtime.Caller(i)
 		if !ok {
-			return nil
+			// The breaks below failed to terminate the loop, and we ran off the
+			// end of the call stack.
+			break
 		}
 
 		// This is a huge edge case, but it will panic if this is the case, see #180
@@ -90,18 +103,30 @@ func CallerInfo() []string {
 			break
 		}
 
-		parts := strings.Split(file, "/")
-		dir := parts[len(parts)-2]
-		file = parts[len(parts)-1]
-		if (dir != "assert" && dir != "mock" && dir != "require") || file == "mock_test.go" {
-			callers = append(callers, fmt.Sprintf("%s:%d", file, line))
-		}
-
 		f := runtime.FuncForPC(pc)
 		if f == nil {
 			break
 		}
 		name = f.Name()
+
+		// testing.tRunner is the standard library function that calls
+		// tests. Subtests are called directly by tRunner, without going through
+		// the Test/Benchmark/Example function that contains the t.Run calls, so
+		// with subtests we should break when we hit tRunner, without adding it
+		// to the list of callers.
+		if name == "testing.tRunner" {
+			break
+		}
+
+		parts := strings.Split(file, "/")
+		file = parts[len(parts)-1]
+		if len(parts) > 1 {
+			dir := parts[len(parts)-2]
+			if (dir != "assert" && dir != "mock" && dir != "require") || file == "mock_test.go" {
+				callers = append(callers, fmt.Sprintf("%s:%d", file, line))
+			}
+		}
+
 		// Drop the package
 		segments := strings.Split(name, ".")
 		name = segments[len(segments)-1]
@@ -141,7 +166,7 @@ func getWhitespaceString() string {
 	parts := strings.Split(file, "/")
 	file = parts[len(parts)-1]
 
-	return strings.Repeat(" ", len(fmt.Sprintf("%s:%d:      ", file, line)))
+	return strings.Repeat(" ", len(fmt.Sprintf("%s:%d:        ", file, line)))
 
 }
 
@@ -158,22 +183,18 @@ func messageFromMsgAndArgs(msgAndArgs ...interface{}) string {
 	return ""
 }
 
-// Indents all lines of the message by appending a number of tabs to each line, in an output format compatible with Go's
-// test printing (see inner comment for specifics)
-func indentMessageLines(message string, tabs int) string {
+// Aligns the provided message so that all lines after the first line start at the same location as the first line.
+// Assumes that the first line starts at the correct location (after carriage return, tab, label, spacer and tab).
+// The longestLabelLen parameter specifies the length of the longest label in the output (required becaues this is the
+// basis on which the alignment occurs).
+func indentMessageLines(message string, longestLabelLen int) string {
 	outBuf := new(bytes.Buffer)
 
 	for i, scanner := 0, bufio.NewScanner(strings.NewReader(message)); scanner.Scan(); i++ {
+		// no need to align first line because it starts at the correct location (after the label)
 		if i != 0 {
-			outBuf.WriteRune('\n')
-		}
-		for ii := 0; ii < tabs; ii++ {
-			outBuf.WriteRune('\t')
-			// Bizarrely, all lines except the first need one fewer tabs prepended, so deliberately advance the counter
-			// by 1 prematurely.
-			if ii == 0 && i > 0 {
-				ii++
-			}
+			// append alignLen+1 spaces to align with "{{longestLabel}}:" before adding tab
+			outBuf.WriteString("\n\r\t" + strings.Repeat(" ", longestLabelLen+1) + "\t")
 		}
 		outBuf.WriteString(scanner.Text())
 	}
@@ -181,34 +202,76 @@ func indentMessageLines(message string, tabs int) string {
 	return outBuf.String()
 }
 
+type failNower interface {
+	FailNow()
+}
+
+// FailNow fails test
+func FailNow(t TestingT, failureMessage string, msgAndArgs ...interface{}) bool {
+	Fail(t, failureMessage, msgAndArgs...)
+
+	// We cannot extend TestingT with FailNow() and
+	// maintain backwards compatibility, so we fallback
+	// to panicking when FailNow is not available in
+	// TestingT.
+	// See issue #263
+
+	if t, ok := t.(failNower); ok {
+		t.FailNow()
+	} else {
+		panic("test failed and t is missing `FailNow()`")
+	}
+	return false
+}
+
 // Fail reports a failure through
 func Fail(t TestingT, failureMessage string, msgAndArgs ...interface{}) bool {
+	content := []labeledContent{
+		{"Error Trace", strings.Join(CallerInfo(), "\n\r\t\t\t")},
+		{"Error", failureMessage},
+	}
 
 	message := messageFromMsgAndArgs(msgAndArgs...)
-
-	errorTrace := strings.Join(CallerInfo(), "\n\r\t\t\t")
 	if len(message) > 0 {
-		t.Errorf("\r%s\r\tError Trace:\t%s\n"+
-			"\r\tError:%s\n"+
-			"\r\tMessages:\t%s\n\r",
-			getWhitespaceString(),
-			errorTrace,
-			indentMessageLines(failureMessage, 2),
-			message)
-	} else {
-		t.Errorf("\r%s\r\tError Trace:\t%s\n"+
-			"\r\tError:%s\n\r",
-			getWhitespaceString(),
-			errorTrace,
-			indentMessageLines(failureMessage, 2))
+		content = append(content, labeledContent{"Messages", message})
 	}
 
+	t.Errorf("%s", "\r"+getWhitespaceString()+labeledOutput(content...))
+
 	return false
 }
 
+type labeledContent struct {
+	label   string
+	content string
+}
+
+// labeledOutput returns a string consisting of the provided labeledContent. Each labeled output is appended in the following manner:
+//
+//   \r\t{{label}}:{{align_spaces}}\t{{content}}\n
+//
+// The initial carriage return is required to undo/erase any padding added by testing.T.Errorf. The "\t{{label}}:" is for the label.
+// If a label is shorter than the longest label provided, padding spaces are added to make all the labels match in length. Once this
+// alignment is achieved, "\t{{content}}\n" is added for the output.
+//
+// If the content of the labeledOutput contains line breaks, the subsequent lines are aligned so that they start at the same location as the first line.
+func labeledOutput(content ...labeledContent) string {
+	longestLabel := 0
+	for _, v := range content {
+		if len(v.label) > longestLabel {
+			longestLabel = len(v.label)
+		}
+	}
+	var output string
+	for _, v := range content {
+		output += "\r\t" + v.label + ":" + strings.Repeat(" ", longestLabel-len(v.label)) + "\t" + indentMessageLines(v.content, longestLabel) + "\n"
+	}
+	return output
+}
+
 // Implements asserts that an object is implemented by the specified interface.
 //
-//    assert.Implements(t, (*MyInterface)(nil), new(MyObject), "MyObject")
+//    assert.Implements(t, (*MyInterface)(nil), new(MyObject))
 func Implements(t TestingT, interfaceObject interface{}, object interface{}, msgAndArgs ...interface{}) bool {
 
 	interfaceType := reflect.TypeOf(interfaceObject).Elem()
@@ -233,32 +296,61 @@ func IsType(t TestingT, expectedType interface{}, object interface{}, msgAndArgs
 
 // Equal asserts that two objects are equal.
 //
-//    assert.Equal(t, 123, 123, "123 and 123 should be equal")
+//    assert.Equal(t, 123, 123)
 //
 // Returns whether the assertion was successful (true) or not (false).
+//
+// Pointer variable equality is determined based on the equality of the
+// referenced values (as opposed to the memory addresses). Function equality
+// cannot be determined and will always fail.
 func Equal(t TestingT, expected, actual interface{}, msgAndArgs ...interface{}) bool {
+	if err := validateEqualArgs(expected, actual); err != nil {
+		return Fail(t, fmt.Sprintf("Invalid operation: %#v == %#v (%s)",
+			expected, actual, err), msgAndArgs...)
+	}
 
 	if !ObjectsAreEqual(expected, actual) {
 		diff := diff(expected, actual)
-		return Fail(t, fmt.Sprintf("Not equal: %#v (expected)\n"+
-			"        != %#v (actual)%s", expected, actual, diff), msgAndArgs...)
+		expected, actual = formatUnequalValues(expected, actual)
+		return Fail(t, fmt.Sprintf("Not equal: \n"+
+			"expected: %s\n"+
+			"actual: %s%s", expected, actual, diff), msgAndArgs...)
 	}
 
 	return true
 
 }
 
+// formatUnequalValues takes two values of arbitrary types and returns string
+// representations appropriate to be presented to the user.
+//
+// If the values are not of like type, the returned strings will be prefixed
+// with the type name, and the value will be enclosed in parenthesis similar
+// to a type conversion in the Go grammar.
+func formatUnequalValues(expected, actual interface{}) (e string, a string) {
+	if reflect.TypeOf(expected) != reflect.TypeOf(actual) {
+		return fmt.Sprintf("%T(%#v)", expected, expected),
+			fmt.Sprintf("%T(%#v)", actual, actual)
+	}
+
+	return fmt.Sprintf("%#v", expected),
+		fmt.Sprintf("%#v", actual)
+}
+
 // EqualValues asserts that two objects are equal or convertable to the same types
 // and equal.
 //
-//    assert.EqualValues(t, uint32(123), int32(123), "123 and 123 should be equal")
+//    assert.EqualValues(t, uint32(123), int32(123))
 //
 // Returns whether the assertion was successful (true) or not (false).
 func EqualValues(t TestingT, expected, actual interface{}, msgAndArgs ...interface{}) bool {
 
 	if !ObjectsAreEqualValues(expected, actual) {
-		return Fail(t, fmt.Sprintf("Not equal: %#v (expected)\n"+
-			"        != %#v (actual)", expected, actual), msgAndArgs...)
+		diff := diff(expected, actual)
+		expected, actual = formatUnequalValues(expected, actual)
+		return Fail(t, fmt.Sprintf("Not equal: \n"+
+			"expected: %s\n"+
+			"actual: %s%s", expected, actual, diff), msgAndArgs...)
 	}
 
 	return true
@@ -267,7 +359,7 @@ func EqualValues(t TestingT, expected, actual interface{}, msgAndArgs ...interfa
 
 // Exactly asserts that two objects are equal is value and type.
 //
-//    assert.Exactly(t, int32(123), int64(123), "123 and 123 should NOT be equal")
+//    assert.Exactly(t, int32(123), int64(123))
 //
 // Returns whether the assertion was successful (true) or not (false).
 func Exactly(t TestingT, expected, actual interface{}, msgAndArgs ...interface{}) bool {
@@ -285,7 +377,7 @@ func Exactly(t TestingT, expected, actual interface{}, msgAndArgs ...interface{}
 
 // NotNil asserts that the specified object is not nil.
 //
-//    assert.NotNil(t, err, "err should be something")
+//    assert.NotNil(t, err)
 //
 // Returns whether the assertion was successful (true) or not (false).
 func NotNil(t TestingT, object interface{}, msgAndArgs ...interface{}) bool {
@@ -312,7 +404,7 @@ func isNil(object interface{}) bool {
 
 // Nil asserts that the specified object is nil.
 //
-//    assert.Nil(t, err, "err should be nothing")
+//    assert.Nil(t, err)
 //
 // Returns whether the assertion was successful (true) or not (false).
 func Nil(t TestingT, object interface{}, msgAndArgs ...interface{}) bool {
@@ -363,6 +455,11 @@ func isEmpty(object interface{}) bool {
 		{
 			return (objValue.Len() == 0)
 		}
+	case reflect.Struct:
+		switch object.(type) {
+		case time.Time:
+			return object.(time.Time).IsZero()
+		}
 	case reflect.Ptr:
 		{
 			if objValue.IsNil() {
@@ -430,7 +527,7 @@ func getLen(x interface{}) (ok bool, length int) {
 // Len asserts that the specified object has specific length.
 // Len also fails if the object has a type that len() not accept.
 //
-//    assert.Len(t, mySlice, 3, "The size of slice is not 3")
+//    assert.Len(t, mySlice, 3)
 //
 // Returns whether the assertion was successful (true) or not (false).
 func Len(t TestingT, object interface{}, length int, msgAndArgs ...interface{}) bool {
@@ -447,7 +544,7 @@ func Len(t TestingT, object interface{}, length int, msgAndArgs ...interface{})
 
 // True asserts that the specified value is true.
 //
-//    assert.True(t, myBool, "myBool should be true")
+//    assert.True(t, myBool)
 //
 // Returns whether the assertion was successful (true) or not (false).
 func True(t TestingT, value bool, msgAndArgs ...interface{}) bool {
@@ -462,7 +559,7 @@ func True(t TestingT, value bool, msgAndArgs ...interface{}) bool {
 
 // False asserts that the specified value is false.
 //
-//    assert.False(t, myBool, "myBool should be false")
+//    assert.False(t, myBool)
 //
 // Returns whether the assertion was successful (true) or not (false).
 func False(t TestingT, value bool, msgAndArgs ...interface{}) bool {
@@ -477,10 +574,17 @@ func False(t TestingT, value bool, msgAndArgs ...interface{}) bool {
 
 // NotEqual asserts that the specified values are NOT equal.
 //
-//    assert.NotEqual(t, obj1, obj2, "two objects shouldn't be equal")
+//    assert.NotEqual(t, obj1, obj2)
 //
 // Returns whether the assertion was successful (true) or not (false).
+//
+// Pointer variable equality is determined based on the equality of the
+// referenced values (as opposed to the memory addresses).
 func NotEqual(t TestingT, expected, actual interface{}, msgAndArgs ...interface{}) bool {
+	if err := validateEqualArgs(expected, actual); err != nil {
+		return Fail(t, fmt.Sprintf("Invalid operation: %#v != %#v (%s)",
+			expected, actual, err), msgAndArgs...)
+	}
 
 	if ObjectsAreEqual(expected, actual) {
 		return Fail(t, fmt.Sprintf("Should not be: %#v\n", actual), msgAndArgs...)
@@ -531,9 +635,9 @@ func includeElement(list interface{}, element interface{}) (ok, found bool) {
 // Contains asserts that the specified string, list(array, slice...) or map contains the
 // specified substring or element.
 //
-//    assert.Contains(t, "Hello World", "World", "But 'Hello World' does contain 'World'")
-//    assert.Contains(t, ["Hello", "World"], "World", "But ["Hello", "World"] does contain 'World'")
-//    assert.Contains(t, {"Hello": "World"}, "Hello", "But {'Hello': 'World'} does contain 'Hello'")
+//    assert.Contains(t, "Hello World", "World")
+//    assert.Contains(t, ["Hello", "World"], "World")
+//    assert.Contains(t, {"Hello": "World"}, "Hello")
 //
 // Returns whether the assertion was successful (true) or not (false).
 func Contains(t TestingT, s, contains interface{}, msgAndArgs ...interface{}) bool {
@@ -553,9 +657,9 @@ func Contains(t TestingT, s, contains interface{}, msgAndArgs ...interface{}) bo
 // NotContains asserts that the specified string, list(array, slice...) or map does NOT contain the
 // specified substring or element.
 //
-//    assert.NotContains(t, "Hello World", "Earth", "But 'Hello World' does NOT contain 'Earth'")
-//    assert.NotContains(t, ["Hello", "World"], "Earth", "But ['Hello', 'World'] does NOT contain 'Earth'")
-//    assert.NotContains(t, {"Hello": "World"}, "Earth", "But {'Hello': 'World'} does NOT contain 'Earth'")
+//    assert.NotContains(t, "Hello World", "Earth")
+//    assert.NotContains(t, ["Hello", "World"], "Earth")
+//    assert.NotContains(t, {"Hello": "World"}, "Earth")
 //
 // Returns whether the assertion was successful (true) or not (false).
 func NotContains(t TestingT, s, contains interface{}, msgAndArgs ...interface{}) bool {
@@ -572,6 +676,92 @@ func NotContains(t TestingT, s, contains interface{}, msgAndArgs ...interface{})
 
 }
 
+// Subset asserts that the specified list(array, slice...) contains all
+// elements given in the specified subset(array, slice...).
+//
+//    assert.Subset(t, [1, 2, 3], [1, 2], "But [1, 2, 3] does contain [1, 2]")
+//
+// Returns whether the assertion was successful (true) or not (false).
+func Subset(t TestingT, list, subset interface{}, msgAndArgs ...interface{}) (ok bool) {
+	if subset == nil {
+		return true // we consider nil to be equal to the nil set
+	}
+
+	subsetValue := reflect.ValueOf(subset)
+	defer func() {
+		if e := recover(); e != nil {
+			ok = false
+		}
+	}()
+
+	listKind := reflect.TypeOf(list).Kind()
+	subsetKind := reflect.TypeOf(subset).Kind()
+
+	if listKind != reflect.Array && listKind != reflect.Slice {
+		return Fail(t, fmt.Sprintf("%q has an unsupported type %s", list, listKind), msgAndArgs...)
+	}
+
+	if subsetKind != reflect.Array && subsetKind != reflect.Slice {
+		return Fail(t, fmt.Sprintf("%q has an unsupported type %s", subset, subsetKind), msgAndArgs...)
+	}
+
+	for i := 0; i < subsetValue.Len(); i++ {
+		element := subsetValue.Index(i).Interface()
+		ok, found := includeElement(list, element)
+		if !ok {
+			return Fail(t, fmt.Sprintf("\"%s\" could not be applied builtin len()", list), msgAndArgs...)
+		}
+		if !found {
+			return Fail(t, fmt.Sprintf("\"%s\" does not contain \"%s\"", list, element), msgAndArgs...)
+		}
+	}
+
+	return true
+}
+
+// NotSubset asserts that the specified list(array, slice...) contains not all
+// elements given in the specified subset(array, slice...).
+//
+//    assert.NotSubset(t, [1, 3, 4], [1, 2], "But [1, 3, 4] does not contain [1, 2]")
+//
+// Returns whether the assertion was successful (true) or not (false).
+func NotSubset(t TestingT, list, subset interface{}, msgAndArgs ...interface{}) (ok bool) {
+	if subset == nil {
+		return false // we consider nil to be equal to the nil set
+	}
+
+	subsetValue := reflect.ValueOf(subset)
+	defer func() {
+		if e := recover(); e != nil {
+			ok = false
+		}
+	}()
+
+	listKind := reflect.TypeOf(list).Kind()
+	subsetKind := reflect.TypeOf(subset).Kind()
+
+	if listKind != reflect.Array && listKind != reflect.Slice {
+		return Fail(t, fmt.Sprintf("%q has an unsupported type %s", list, listKind), msgAndArgs...)
+	}
+
+	if subsetKind != reflect.Array && subsetKind != reflect.Slice {
+		return Fail(t, fmt.Sprintf("%q has an unsupported type %s", subset, subsetKind), msgAndArgs...)
+	}
+
+	for i := 0; i < subsetValue.Len(); i++ {
+		element := subsetValue.Index(i).Interface()
+		ok, found := includeElement(list, element)
+		if !ok {
+			return Fail(t, fmt.Sprintf("\"%s\" could not be applied builtin len()", list), msgAndArgs...)
+		}
+		if !found {
+			return true
+		}
+	}
+
+	return Fail(t, fmt.Sprintf("%q is a subset of %q", subset, list), msgAndArgs...)
+}
+
 // Condition uses a Comparison to assert a complex condition.
 func Condition(t TestingT, comp Comparison, msgAndArgs ...interface{}) bool {
 	result := comp()
@@ -609,9 +799,7 @@ func didPanic(f PanicTestFunc) (bool, interface{}) {
 
 // Panics asserts that the code inside the specified PanicTestFunc panics.
 //
-//   assert.Panics(t, func(){
-//     GoCrazy()
-//   }, "Calling GoCrazy() should panic")
+//   assert.Panics(t, func(){ GoCrazy() })
 //
 // Returns whether the assertion was successful (true) or not (false).
 func Panics(t TestingT, f PanicTestFunc, msgAndArgs ...interface{}) bool {
@@ -623,11 +811,28 @@ func Panics(t TestingT, f PanicTestFunc, msgAndArgs ...interface{}) bool {
 	return true
 }
 
+// PanicsWithValue asserts that the code inside the specified PanicTestFunc panics, and that
+// the recovered panic value equals the expected panic value.
+//
+//   assert.PanicsWithValue(t, "crazy error", func(){ GoCrazy() })
+//
+// Returns whether the assertion was successful (true) or not (false).
+func PanicsWithValue(t TestingT, expected interface{}, f PanicTestFunc, msgAndArgs ...interface{}) bool {
+
+	funcDidPanic, panicValue := didPanic(f)
+	if !funcDidPanic {
+		return Fail(t, fmt.Sprintf("func %#v should panic\n\r\tPanic value:\t%v", f, panicValue), msgAndArgs...)
+	}
+	if panicValue != expected {
+		return Fail(t, fmt.Sprintf("func %#v should panic with value:\t%v\n\r\tPanic value:\t%v", f, expected, panicValue), msgAndArgs...)
+	}
+
+	return true
+}
+
 // NotPanics asserts that the code inside the specified PanicTestFunc does NOT panic.
 //
-//   assert.NotPanics(t, func(){
-//     RemainCalm()
-//   }, "Calling RemainCalm() should NOT panic")
+//   assert.NotPanics(t, func(){ RemainCalm() })
 //
 // Returns whether the assertion was successful (true) or not (false).
 func NotPanics(t TestingT, f PanicTestFunc, msgAndArgs ...interface{}) bool {
@@ -641,7 +846,7 @@ func NotPanics(t TestingT, f PanicTestFunc, msgAndArgs ...interface{}) bool {
 
 // WithinDuration asserts that the two times are within duration delta of each other.
 //
-//   assert.WithinDuration(t, time.Now(), time.Now(), 10*time.Second, "The difference should not be more than 10s")
+//   assert.WithinDuration(t, time.Now(), time.Now(), 10*time.Second)
 //
 // Returns whether the assertion was successful (true) or not (false).
 func WithinDuration(t TestingT, expected, actual time.Time, delta time.Duration, msgAndArgs ...interface{}) bool {
@@ -730,7 +935,7 @@ func InDeltaSlice(t TestingT, expected, actual interface{}, delta float64, msgAn
 	expectedSlice := reflect.ValueOf(expected)
 
 	for i := 0; i < actualSlice.Len(); i++ {
-		result := InDelta(t, actualSlice.Index(i).Interface(), expectedSlice.Index(i).Interface(), delta)
+		result := InDelta(t, actualSlice.Index(i).Interface(), expectedSlice.Index(i).Interface(), delta, msgAndArgs...)
 		if !result {
 			return result
 		}
@@ -739,42 +944,40 @@ func InDeltaSlice(t TestingT, expected, actual interface{}, delta float64, msgAn
 	return true
 }
 
-// min(|expected|, |actual|) * epsilon
-func calcEpsilonDelta(expected, actual interface{}, epsilon float64) float64 {
+func calcRelativeError(expected, actual interface{}) (float64, error) {
 	af, aok := toFloat(expected)
+	if !aok {
+		return 0, fmt.Errorf("expected value %q cannot be converted to float", expected)
+	}
+	if af == 0 {
+		return 0, fmt.Errorf("expected value must have a value other than zero to calculate the relative error")
+	}
 	bf, bok := toFloat(actual)
-
-	if !aok || !bok {
-		// invalid input
-		return 0
+	if !bok {
+		return 0, fmt.Errorf("expected value %q cannot be converted to float", actual)
 	}
 
-	if af < 0 {
-		af = -af
-	}
-	if bf < 0 {
-		bf = -bf
-	}
-	var delta float64
-	if af < bf {
-		delta = af * epsilon
-	} else {
-		delta = bf * epsilon
-	}
-	return delta
+	return math.Abs(af-bf) / math.Abs(af), nil
 }
 
 // InEpsilon asserts that expected and actual have a relative error less than epsilon
 //
 // Returns whether the assertion was successful (true) or not (false).
 func InEpsilon(t TestingT, expected, actual interface{}, epsilon float64, msgAndArgs ...interface{}) bool {
-	delta := calcEpsilonDelta(expected, actual, epsilon)
+	actualEpsilon, err := calcRelativeError(expected, actual)
+	if err != nil {
+		return Fail(t, err.Error(), msgAndArgs...)
+	}
+	if actualEpsilon > epsilon {
+		return Fail(t, fmt.Sprintf("Relative error is too high: %#v (expected)\n"+
+			"        < %#v (actual)", actualEpsilon, epsilon), msgAndArgs...)
+	}
 
-	return InDelta(t, expected, actual, delta, msgAndArgs...)
+	return true
 }
 
-// InEpsilonSlice is the same as InEpsilon, except it compares two slices.
-func InEpsilonSlice(t TestingT, expected, actual interface{}, delta float64, msgAndArgs ...interface{}) bool {
+// InEpsilonSlice is the same as InEpsilon, except it compares each value from two slices.
+func InEpsilonSlice(t TestingT, expected, actual interface{}, epsilon float64, msgAndArgs ...interface{}) bool {
 	if expected == nil || actual == nil ||
 		reflect.TypeOf(actual).Kind() != reflect.Slice ||
 		reflect.TypeOf(expected).Kind() != reflect.Slice {
@@ -785,7 +988,7 @@ func InEpsilonSlice(t TestingT, expected, actual interface{}, delta float64, msg
 	expectedSlice := reflect.ValueOf(expected)
 
 	for i := 0; i < actualSlice.Len(); i++ {
-		result := InEpsilon(t, actualSlice.Index(i).Interface(), expectedSlice.Index(i).Interface(), delta)
+		result := InEpsilon(t, actualSlice.Index(i).Interface(), expectedSlice.Index(i).Interface(), epsilon)
 		if !result {
 			return result
 		}
@@ -802,51 +1005,55 @@ func InEpsilonSlice(t TestingT, expected, actual interface{}, delta float64, msg
 //
 //   actualObj, err := SomeFunction()
 //   if assert.NoError(t, err) {
-//	   assert.Equal(t, actualObj, expectedObj)
+//	   assert.Equal(t, expectedObj, actualObj)
 //   }
 //
 // Returns whether the assertion was successful (true) or not (false).
 func NoError(t TestingT, err error, msgAndArgs ...interface{}) bool {
-	if isNil(err) {
-		return true
+	if err != nil {
+		return Fail(t, fmt.Sprintf("Received unexpected error:\n%+v", err), msgAndArgs...)
 	}
 
-	return Fail(t, fmt.Sprintf("Received unexpected error %q", err), msgAndArgs...)
+	return true
 }
 
 // Error asserts that a function returned an error (i.e. not `nil`).
 //
 //   actualObj, err := SomeFunction()
-//   if assert.Error(t, err, "An error was expected") {
-//	   assert.Equal(t, err, expectedError)
+//   if assert.Error(t, err) {
+//	   assert.Equal(t, expectedError, err)
 //   }
 //
 // Returns whether the assertion was successful (true) or not (false).
 func Error(t TestingT, err error, msgAndArgs ...interface{}) bool {
 
-	message := messageFromMsgAndArgs(msgAndArgs...)
-	return NotNil(t, err, "An error is expected but got nil. %s", message)
+	if err == nil {
+		return Fail(t, "An error is expected but got nil.", msgAndArgs...)
+	}
 
+	return true
 }
 
 // EqualError asserts that a function returned an error (i.e. not `nil`)
 // and that it is equal to the provided error.
 //
 //   actualObj, err := SomeFunction()
-//   if assert.Error(t, err, "An error was expected") {
-//	   assert.Equal(t, err, expectedError)
-//   }
+//   assert.EqualError(t, err,  expectedErrorString)
 //
 // Returns whether the assertion was successful (true) or not (false).
 func EqualError(t TestingT, theError error, errString string, msgAndArgs ...interface{}) bool {
-
-	message := messageFromMsgAndArgs(msgAndArgs...)
-	if !NotNil(t, theError, "An error is expected but got nil. %s", message) {
+	if !Error(t, theError, msgAndArgs...) {
 		return false
 	}
-	s := "An error with value \"%s\" is expected but got \"%s\". %s"
-	return Equal(t, errString, theError.Error(),
-		s, errString, theError.Error(), message)
+	expected := errString
+	actual := theError.Error()
+	// don't need to use deep equals here, we know they are both strings
+	if expected != actual {
+		return Fail(t, fmt.Sprintf("Error message not equal:\n"+
+			"expected: %q\n"+
+			"actual: %q", expected, actual), msgAndArgs...)
+	}
+	return true
 }
 
 // matchRegexp return true if a specified regexp matches a string.
@@ -961,9 +1168,8 @@ func diff(expected interface{}, actual interface{}) string {
 		return ""
 	}
 
-	spew.Config.SortKeys = true
-	e := spew.Sdump(expected)
-	a := spew.Sdump(actual)
+	e := spewConfig.Sdump(expected)
+	a := spewConfig.Sdump(actual)
 
 	diff, _ := difflib.GetUnifiedDiffString(difflib.UnifiedDiff{
 		A:        difflib.SplitLines(e),
@@ -977,3 +1183,26 @@ func diff(expected interface{}, actual interface{}) string {
 
 	return "\n\nDiff:\n" + diff
 }
+
+// validateEqualArgs checks whether provided arguments can be safely used in the
+// Equal/NotEqual functions.
+func validateEqualArgs(expected, actual interface{}) error {
+	if isFunction(expected) || isFunction(actual) {
+		return errors.New("cannot take func type as argument")
+	}
+	return nil
+}
+
+func isFunction(arg interface{}) bool {
+	if arg == nil {
+		return false
+	}
+	return reflect.TypeOf(arg).Kind() == reflect.Func
+}
+
+var spewConfig = spew.ConfigState{
+	Indent:                  " ",
+	DisablePointerAddresses: true,
+	DisableCapacities:       true,
+	SortKeys:                true,
+}