Switch to ginkgo/gomega for tests

This switches over to ginkgo/gomega for tests, which makes writing
certain tests easier/more fluent in the future.

vendor/github.com/onsi/gomega/matchers/match_yaml_matcher.go

@@ -0,0 +1,76 @@
+package matchers
+
+import (
+	"fmt"
+	"strings"
+
+	"github.com/onsi/gomega/format"
+	"gopkg.in/yaml.v2"
+)
+
+type MatchYAMLMatcher struct {
+	YAMLToMatch      interface{}
+	firstFailurePath []interface{}
+}
+
+func (matcher *MatchYAMLMatcher) Match(actual interface{}) (success bool, err error) {
+	actualString, expectedString, err := matcher.toStrings(actual)
+	if err != nil {
+		return false, err
+	}
+
+	var aval interface{}
+	var eval interface{}
+
+	if err := yaml.Unmarshal([]byte(actualString), &aval); err != nil {
+		return false, fmt.Errorf("Actual '%s' should be valid YAML, but it is not.\nUnderlying error:%s", actualString, err)
+	}
+	if err := yaml.Unmarshal([]byte(expectedString), &eval); err != nil {
+		return false, fmt.Errorf("Expected '%s' should be valid YAML, but it is not.\nUnderlying error:%s", expectedString, err)
+	}
+
+	var equal bool
+	equal, matcher.firstFailurePath = deepEqual(aval, eval)
+	return equal, nil
+}
+
+func (matcher *MatchYAMLMatcher) FailureMessage(actual interface{}) (message string) {
+	actualString, expectedString, _ := matcher.toNormalisedStrings(actual)
+	return formattedMessage(format.Message(actualString, "to match YAML of", expectedString), matcher.firstFailurePath)
+}
+
+func (matcher *MatchYAMLMatcher) NegatedFailureMessage(actual interface{}) (message string) {
+	actualString, expectedString, _ := matcher.toNormalisedStrings(actual)
+	return formattedMessage(format.Message(actualString, "not to match YAML of", expectedString), matcher.firstFailurePath)
+}
+
+func (matcher *MatchYAMLMatcher) toNormalisedStrings(actual interface{}) (actualFormatted, expectedFormatted string, err error) {
+	actualString, expectedString, err := matcher.toStrings(actual)
+	return normalise(actualString), normalise(expectedString), err
+}
+
+func normalise(input string) string {
+	var val interface{}
+	err := yaml.Unmarshal([]byte(input), &val)
+	if err != nil {
+		panic(err) // guarded by Match
+	}
+	output, err := yaml.Marshal(val)
+	if err != nil {
+		panic(err) // guarded by Unmarshal
+	}
+	return strings.TrimSpace(string(output))
+}
+
+func (matcher *MatchYAMLMatcher) toStrings(actual interface{}) (actualFormatted, expectedFormatted string, err error) {
+	actualString, ok := toString(actual)
+	if !ok {
+		return "", "", fmt.Errorf("MatchYAMLMatcher matcher requires a string, stringer, or []byte.  Got actual:\n%s", format.Object(actual, 1))
+	}
+	expectedString, ok := toString(matcher.YAMLToMatch)
+	if !ok {
+		return "", "", fmt.Errorf("MatchYAMLMatcher matcher requires a string, stringer, or []byte.  Got expected:\n%s", format.Object(matcher.YAMLToMatch, 1))
+	}
+
+	return actualString, expectedString, nil
+}