template.go

package openmock

import (
	"bytes"
	"net/http"
	"regexp"
	"text/template"

	"github.com/Masterminds/sprig"
	"github.com/imdario/mergo"
	"github.com/labstack/echo/v4"
	"github.com/sirupsen/logrus"
)

// Context represents the context of the mock expectation
type Context struct {
	HTTPContext     echo.Context
	HTTPHeader      http.Header
	HTTPBody        string
	HTTPPath        string
	HTTPQueryString string

	GRPCService string
	GRPCMethod  string
	GRPCContext echo.Context
	GRPCHeader  http.Header
	GRPCPayload string

	KafkaTopic   string
	KafkaPayload string

	AMQPExchange   string
	AMQPRoutingKey string
	AMQPQueue      string
	AMQPPayload    string

	Values map[string]interface{}

	om          *OpenMock
	currentMock *Mock
}

var globalTemplate = template.New("__global__")

// cleanup replaces all the linebreaks and tabs with spaces
func cleanup(raw string) string {
	re := regexp.MustCompile(`\r?\n|\t`)
	return re.ReplaceAllString(raw, " ")
}

// Create a new context that combines values in this context with values in the
// other context if not blank
func (c Context) Merge(other Context) (out Context) {
	mergo.Merge(&out, other)
	mergo.Merge(&out, c)
	return out
}

// Render renders the raw given the context
func (c Context) Render(raw string) (out string, err error) {
	tmpl, err := globalTemplate.New("").
		Funcs(sprig.TxtFuncMap()). // supported functions https://github.com/Masterminds/sprig/blob/master/functions.go
		Funcs(genLocalFuncMap(c.om)).
		Option("missingkey=error").
		Parse(cleanup(raw))
	if err != nil {
		return "", err
	}
	buf := &bytes.Buffer{}
	if err := tmpl.Execute(buf, c); err != nil {
		return "", err
	}
	return buf.String(), nil
}

// MatchCondition checks the condition given the context
func (c Context) MatchCondition(condition string) (r bool) {
	logger := newOmLogger(c)
	defer func() {
		if r {
			logger.Info("ok match condition")
			logger.WithFields(logrus.Fields{
				"HTTPHeader":   c.HTTPHeader,
				"HTTPBody":     c.HTTPBody,
				"GRPCHeader":   c.GRPCHeader,
				"GRPCPayload":  c.GRPCPayload,
				"KafkaPayload": c.KafkaPayload,
				"AMQPPayload":  c.AMQPPayload,
				"condition":    condition,
				"result":       r,
			}).Debug("running MatchCondition")
		}
	}()

	if condition == "" {
		return true
	}

	result, err := c.Render(condition)
	if err != nil {
		logger.WithField("err", err).Errorf("failed to render condition: %s", condition)
		return false
	}
	return result == "true"
}