Add gomock matcher utilities

gomock_matchers/path.go

@@ -0,0 +1,35 @@
+package matchers
+
+import (
+	"fmt"
+	"path"
+	"strings"
+)
+
+// Path is a pathname matcher.
+//
+// A value matches if it is the same as the matcher pattern or has the matcher
+// pattern as a trailing component.  For example,
+// a pattern "abc/def" matches "abc/def" itself, "omg/abc/def",
+// but not "abc/def/wtf", "abc/omg/def", or "xabc/def".
+//
+// Both the pattern and the value are sanitized using path.Clean() before use.
+//
+// The empty pattern "" matches only the empty value "".
+type Path string
+
+// Matches returns whether x is the matching pathname itself or ends with the
+// matching pathname, inside another directory.
+func (p Path) Matches(x interface{}) bool {
+	if s, ok := x.(string); ok {
+		p1 := path.Clean(string(p))
+		s = path.Clean(s)
+		return s == p1 || strings.HasSuffix(s, "/"+p1)
+	}
+	return false
+}
+
+// String returns the string representation of this pathname matcher.
+func (p Path) String() string {
+	return fmt.Sprintf("<path suffix %#v>", path.Clean(string(p)))
+}

gomock_matchers/path_test.go

@@ -0,0 +1,51 @@
+package matchers
+
+import "testing"
+
+func TestPathMatcher_Matches(t *testing.T) {
+	tests := []struct {
+		name string
+		p    Path
+		x    interface{}
+		want bool
+	}{
+		{"EmptyMatchesEmpty", "", "", true},
+		{"EmptyDoesNotMatchNonEmpty", "", "a", false},
+		{"EmptyDoesNotMatchNonEmptyEvenWithTrailingSlash", "", "a/", false},
+		{"NonEmptyDoesNotMatchEmpty", "a", "", false},
+		{"ExactIsOK", "abc/def", "abc/def", true},
+		{"SuffixIsOK", "abc/def", "omg/abc/def", true},
+		{"SubstringIsNotOK", "abc/def", "omg/abc/def/wtf", false},
+		{"PrefixIsNotOK", "abc/def", "abc/def/wtf", false},
+		{"InterveningElementIsNotOK", "abc/def", "abc/bbq/def", false},
+		{"GeneralNonMatch", "abc/def", "omg/wtf", false},
+		{"UncleanPattern", "abc//def/", "abc/def", true},
+		{"UncleanArg", "abc/def", "abc//def", true},
+		{"NonStringArg", "a", 'a', false},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := tt.p.Matches(tt.x); got != tt.want {
+				t.Errorf("Path.Matches() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}
+
+func TestPathMatcher_String(t *testing.T) {
+	tests := []struct {
+		name string
+		p    Path
+		want string
+	}{
+		{"General", "abc/def", "<path suffix \"abc/def\">"},
+		{"Unclean", "abc//def/", "<path suffix \"abc/def\">"},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := tt.p.String(); got != tt.want {
+				t.Errorf("Path.String() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}

gomock_matchers/slice.go

@@ -0,0 +1,39 @@
+package matchers
+
+import (
+	"fmt"
+	"reflect"
+)
+
+// Slice is a gomock matcher that matches elements of an array or
+// slice against its own members at the corresponding positions.
+// Each member item in a Slice may be a regular item or a gomock
+// Matcher instance.
+type Slice []interface{}
+
+// Matches returns whether x is a slice with matching elements.
+func (sm Slice) Matches(x interface{}) bool {
+	v := reflect.ValueOf(x)
+	switch v.Kind() {
+	case reflect.Slice, reflect.Array: // OK
+	default:
+		return false
+	}
+	l := v.Len()
+	if l != len(sm) {
+		return false
+	}
+	for i, m := range sm {
+		m1 := toMatcher(m)
+		v1 := v.Index(i).Interface()
+		if !m1.Matches(v1) {
+			return false
+		}
+	}
+	return true
+}
+
+// String returns the string representation of this slice matcher.
+func (sm Slice) String() string {
+	return fmt.Sprint([]interface{}(sm))
+}

gomock_matchers/slice_test.go

@@ -0,0 +1,114 @@
+package matchers
+
+import (
+	"testing"
+
+	"github.com/golang/mock/gomock"
+)
+
+func TestSliceMatcher_Matches(t *testing.T) {
+	tests := []struct {
+		name string
+		sm   Slice
+		x    interface{}
+		want bool
+	}{
+		{
+			"EmptyEqEmpty",
+			Slice{},
+			[]interface{}{},
+			true,
+		},
+		{
+			"EmptyNeNotEmpty",
+			Slice{},
+			[]interface{}{1},
+			false,
+		},
+		{
+			"NotEmptyNeEmpty",
+			Slice{0},
+			[]interface{}{},
+			false,
+		},
+		{
+			"CompareRawValuesUsingEqualityHappy",
+			Slice{1, 2, 3},
+			[]interface{}{1, 2, 3},
+			true,
+		},
+		{
+			"CompareRawValuesUsingEqualityUnhappy",
+			Slice{1, 2, 3},
+			[]interface{}{1, 20, 3},
+			false,
+		},
+		{
+			"CompareMatcherUsingItsMatchesHappy",
+			Slice{gomock.Nil(), gomock.Eq(3)},
+			[]interface{}{nil, 3},
+			true,
+		},
+		{
+			"CompareMatcherUsingItsMatchesUnhappy",
+			Slice{gomock.Nil(), gomock.Eq(3)},
+			[]interface{}{0, 3},
+			false,
+		},
+		{
+			"NestedHappy",
+			Slice{Slice{3}, 30},
+			[]interface{}{[]interface{}{3}, 30},
+			true,
+		},
+		{
+			"NestedUnhappy",
+			Slice{Slice{3}, 30},
+			[]interface{}{[]interface{}{300}, 30},
+			false,
+		},
+		{
+			"MatchSliceOfMoreSpecificTypes",
+			Slice{1, 2, 3},
+			[]int{1, 2, 3},
+			true,
+		},
+		{
+			"AcceptArraysToo",
+			Slice{1, 2, 3},
+			[...]int{1, 2, 3},
+			true,
+		},
+		{
+			"RejectString",
+			Slice{'a', 'b', 'c'},
+			"abc",
+			false,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := tt.sm.Matches(tt.x); got != tt.want {
+				t.Errorf("Slice.Matches() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}
+
+func TestSliceMatcher_String(t *testing.T) {
+	tests := []struct {
+		name string
+		sm   Slice
+		want string
+	}{
+		{"int", []interface{}{3, 5, 7}, "[3 5 7]"},
+		{"string", []interface{}{"omg", "wtf", "bbq"}, "[omg wtf bbq]"},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := tt.sm.String(); got != tt.want {
+				t.Errorf("Slice.String() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}

gomock_matchers/struct.go

@@ -0,0 +1,53 @@
+package matchers
+
+import (
+	"fmt"
+	"reflect"
+	"sort"
+	"strings"
+)
+
+// Struct is a struct member matcher.
+type Struct map[string]interface{}
+
+// Matches returns whether all specified members match.
+func (sm Struct) Matches(x interface{}) bool {
+	v := reflect.ValueOf(x)
+	if v.Kind() == reflect.Ptr {
+		v = v.Elem()
+	}
+	if v.Kind() != reflect.Struct {
+		return false
+	}
+	for n, m := range sm {
+		m1 := toMatcher(m)
+		f := v.FieldByName(n)
+		if f == (reflect.Value{}) {
+			return false
+		}
+		f1 := f.Interface()
+		if !m1.Matches(f1) {
+			return false
+		}
+	}
+	return true
+}
+
+func (sm Struct) String() string {
+	var fields sort.StringSlice
+	for name := range sm {
+		fields = append(fields, name)
+	}
+	sort.Sort(fields)
+	for i, name := range fields {
+		value := sm[name]
+		var vs string
+		if _, ok := value.(fmt.Stringer); ok {
+			vs = fmt.Sprintf("%s", value)
+		} else {
+			vs = fmt.Sprintf("%v", value)
+		}
+		fields[i] = fmt.Sprintf("%s=%s", name, vs)
+	}
+	return "<struct " + strings.Join(fields, " ") + ">"
+}

gomock_matchers/struct_test.go

@@ -0,0 +1,113 @@
+package matchers
+
+import (
+	"testing"
+
+	"github.com/golang/mock/gomock"
+)
+
+type stringable int
+
+func (s stringable) String() string {
+	return "omg"
+}
+
+func TestStructMatcher_Matches(t *testing.T) {
+	type value struct {
+		A int
+		B string
+	}
+	tests := []struct {
+		name string
+		sm   Struct
+		x    interface{}
+		want bool
+	}{
+		{
+			"EmptyMatchesEmpty",
+			Struct{},
+			value{},
+			true,
+		},
+		{
+			"EmptyMatchesAny",
+			Struct{},
+			value{A: 3, B: "omg"},
+			true,
+		},
+		{
+			"EmptyStillDoesNotMatchNonStruct",
+			Struct{},
+			0,
+			false,
+		},
+		{
+			"RegularFieldValuesUseEq1",
+			Struct{"A": 3, "B": "omg"},
+			value{A: 3, B: "omg"},
+			true,
+		},
+		{
+			"RegularFieldValuesUseEq2",
+			Struct{"A": 3, "B": "omg"},
+			value{A: 4, B: "omg"},
+			false,
+		},
+		{
+			"MatchersAreUsedVerbatim1",
+			Struct{"A": gomock.Not(3), "B": gomock.Eq("omg")},
+			value{A: 4, B: "omg"},
+			true,
+		},
+		{
+			"MatchersAreUsedVerbatim2",
+			Struct{"A": gomock.Not(3), "B": gomock.Eq("omg")},
+			value{A: 3, B: "omg"},
+			false,
+		},
+		{
+			"UnspecifiedFieldsAreIgnored",
+			Struct{"A": 3},
+			value{A: 3, B: "omg"},
+			true,
+		},
+		{
+			"MissingFieldsReturnFailure",
+			Struct{"NOTFOUND": 3},
+			value{A: 3},
+			false,
+		},
+		{
+			"DerefsPointer",
+			Struct{"A": 3},
+			&value{A: 3},
+			true,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := tt.sm.Matches(tt.x); got != tt.want {
+				t.Errorf("Struct.Matches() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}
+
+func TestStructMatcher_String(t *testing.T) {
+	tests := []struct {
+		name string
+		sm   Struct
+		want string
+	}{
+		{"UsesStringer", Struct{"A": stringable(0)}, "<struct A=omg>"},
+		{"ReprIfNotStringable", Struct{"A": nil}, "<struct A=<nil>>"},
+		{"SortsByKey", Struct{"B": 3, "A": 4}, "<struct A=4 B=3>"},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := tt.sm.String(); got != tt.want {
+				t.Errorf("Struct.String() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}

gomock_matchers/util.go

@@ -0,0 +1,12 @@
+package matchers
+
+import (
+	"github.com/golang/mock/gomock"
+)
+
+func toMatcher(v interface{}) gomock.Matcher {
+	if m, ok := v.(gomock.Matcher); ok {
+		return m
+	}
+	return gomock.Eq(v)
+}