Issue 21 interaction checker

.github/workflows/go.yml

@@ -20,7 +20,7 @@ jobs:
     - name: Set up Go
       uses: actions/setup-go@v2
       with:
-        go-version: '1.18'
+        go-version: '1.20'
 
     - name: Build
       run: go build -v ./...

README.md

@@ -109,6 +109,13 @@ Useful for unit testing.
     mockClient := aurestmock.New(mockResponses, mockErrors)
 ```
 
+#### 1c. Or use verifier (super-basic consumer interaction testing)
+
+This mock client doesn't make actual requests, but instead you set up a list of
+expected interactions.
+
+This allows doing very simple consumer tests, useful mostly for their documentation value.
+
 #### 2. Response recording
 
 If your tests use Option 1a (playback), you should insert a response recorder in your production stack.

go.mod

@@ -12,6 +12,5 @@ require (
 require (
 	github.com/davecgh/go-spew v1.1.1 // indirect
 	github.com/pmezard/go-difflib v1.0.0 // indirect
-	github.com/stretchr/objx v0.5.0 // indirect
 	gopkg.in/yaml.v3 v3.0.1 // indirect
 )

go.sum

@@ -1,29 +1,16 @@
 github.com/StephanHCB/go-autumn-logging v0.3.0 h1:G0zs8xoth8i8mOeoFgG3Dvk6dIY9dPPJ7wkm6mjaPyY=
 github.com/StephanHCB/go-autumn-logging v0.3.0/go.mod h1:dPABYdECU3XrFib03uXbQFVLftUP5c4YaKSineiw37U=
-github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/go-http-utils/headers v0.0.0-20181008091004-fed159eddc2a h1:v6zMvHuY9yue4+QkG/HQ/W67wvtQmWJ4SDo9aK/GIno=
 github.com/go-http-utils/headers v0.0.0-20181008091004-fed159eddc2a/go.mod h1:I79BieaU4fxrw4LMXby6q5OS9XnoR9UIKLOzDFjUmuw=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
-github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
-github.com/stretchr/objx v0.4.0/go.mod h1:YvHI0jy2hoMjB+UWwv71VJQ9isScKT/TqJzVSSt89Yw=
-github.com/stretchr/objx v0.5.0 h1:1zr/of2m5FGMsad5YfcqgdqdWrIhu+EBEJRhR1U7z/c=
-github.com/stretchr/objx v0.5.0/go.mod h1:Yh+to48EsGEfYuaHDzXPcE3xhTkx73EhmCGUpEOglKo=
-github.com/stretchr/testify v1.7.1/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
-github.com/stretchr/testify v1.8.0/go.mod h1:yNjHg4UonilssWZ8iaSj1OCr/vHnekPRkoO+kdMU+MU=
-github.com/stretchr/testify v1.8.1 h1:w7B6lhMri9wdJUVmEZPGGhZzrYTPvgJArz7wNPgYKsk=
-github.com/stretchr/testify v1.8.1/go.mod h1:w2LPCIKwWwSfY2zedu0+kehJoqGctiVI29o6fzry7u4=
-github.com/stretchr/testify v1.8.2/go.mod h1:w2LPCIKwWwSfY2zedu0+kehJoqGctiVI29o6fzry7u4=
 github.com/stretchr/testify v1.8.4 h1:CcVxjf3Q8PM0mHUKJCdn+eZZtm5yQwehR5yeSVQQcUk=
 github.com/stretchr/testify v1.8.4/go.mod h1:sz/lmYIOXD/1dqDmKjjqLyZ2RngseejIcXlSw2iwfAo=
-github.com/tidwall/tinylru v1.1.0 h1:XY6IUfzVTU9rpwdhKUF6nQdChgCdGjkMfLzbWyiau6I=
-github.com/tidwall/tinylru v1.1.0/go.mod h1:3+bX+TJ2baOLMWTnlyNWHh4QMnFyARg2TLTQ6OFbzw8=
 github.com/tidwall/tinylru v1.2.1 h1:VgBr72c2IEr+V+pCdkPZUwiQ0KJknnWIYbhxAVkYfQk=
 github.com/tidwall/tinylru v1.2.1/go.mod h1:9bQnEduwB6inr2Y7AkBP7JPgCkyrhTV/ZpX0oOOpBI4=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
-gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
 gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
 gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

implementation/verifier/verifier.go

@@ -0,0 +1,169 @@
+package aurestverifier
+
+import (
+	"context"
+	"encoding/json"
+	"errors"
+	"fmt"
+	aurestclientapi "github.com/StephanHCB/go-autumn-restclient/api"
+	"io"
+	"net/http"
+	"net/url"
+	"sort"
+	"strings"
+)
+
+type VerifierImpl struct {
+	expectations    []Expectation
+	firstUnexpected *Request
+}
+
+type Request struct {
+	Name   string // key for the request
+	Method string
+	Header http.Header // currently not tested, just supplied as documentation for now
+	Url    string
+	Body   interface{}
+}
+
+type ResponseOrError struct {
+	Response aurestclientapi.ParsedResponse
+	Error    error
+}
+
+type Expectation struct {
+	Request  Request
+	Response ResponseOrError
+	Matched  bool
+}
+
+func (e Expectation) matches(method string, requestUrl string, requestBody interface{}) bool {
+	// this is a very simple "must match 100%" for the first version
+	urlMatches := e.Request.Url == requestUrl
+	methodMatches := e.Request.Method == method
+	bodyMatches := requestBodyAsString(e.Request.Body) == requestBodyAsString(requestBody)
+
+	return urlMatches && methodMatches && bodyMatches
+}
+
+func requestBodyAsString(requestBody interface{}) string {
+	if requestBody == nil {
+		return ""
+	}
+	if asCustom, ok := requestBody.(aurestclientapi.CustomRequestBody); ok {
+		if b, err := io.ReadAll(asCustom.BodyReader); err == nil {
+			return string(b)
+		} else {
+			return fmt.Sprintf("ERROR: %s", err.Error())
+		}
+	}
+	if asString, ok := requestBody.(string); ok {
+		return asString
+	}
+	if asUrlValues, ok := requestBody.(url.Values); ok {
+		asString := asUrlValues.Encode()
+		return asString
+	}
+
+	marshalled, err := json.Marshal(requestBody)
+	if err != nil {
+		return fmt.Sprintf("ERROR: %s", err.Error())
+	}
+	return string(marshalled)
+}
+
+func headersSortedAsString(spec http.Header) string {
+	var result strings.Builder
+
+	sortedKeys := make([]string, 0)
+	for k, _ := range spec {
+		sortedKeys = append(sortedKeys, k)
+	}
+	sort.Strings(sortedKeys)
+
+	for _, k := range sortedKeys {
+		result.WriteString(fmt.Sprintf("%s: ", k))
+		for _, v := range spec[k] {
+			result.WriteString(fmt.Sprintf("%s ", v))
+		}
+	}
+	return result.String()
+}
+
+func New() (aurestclientapi.Client, *VerifierImpl) {
+	instance := &VerifierImpl{
+		expectations: make([]Expectation, 0),
+	}
+	return instance, instance
+}
+
+func (c *VerifierImpl) Perform(ctx context.Context, method string, requestUrl string, requestBody interface{}, response *aurestclientapi.ParsedResponse) error {
+	expected, err := c.currentExpectation(method, requestUrl, requestBody)
+	if err != nil {
+		return err
+	}
+
+	if expected.Response.Error != nil {
+		return expected.Response.Error
+	}
+
+	mockResponse := expected.Response.Response
+
+	response.Header = mockResponse.Header
+	response.Status = mockResponse.Status
+	response.Time = mockResponse.Time
+	if response.Body != nil && mockResponse.Body != nil {
+		// copy over through json round trip
+		marshalled, _ := json.Marshal(mockResponse.Body)
+		_ = json.Unmarshal(marshalled, response.Body)
+	}
+
+	return nil
+}
+
+func (c *VerifierImpl) currentExpectation(method string, requestUrl string, requestBody interface{}) (Expectation, error) {
+	for i, e := range c.expectations {
+		if !e.Matched {
+			if e.matches(method, requestUrl, requestBody) {
+				c.expectations[i].Matched = true
+				return e, nil
+			} else {
+				if c.firstUnexpected == nil {
+					c.firstUnexpected = &Request{
+						Name:   fmt.Sprintf("unmatched expectation %d - %s", i+1, e.Request.Name),
+						Method: method,
+						Header: nil, // not currently available
+						Url:    requestUrl,
+						Body:   requestBody,
+					}
+				}
+				return Expectation{}, fmt.Errorf("unmatched expectation %d - %s", i+1, e.Request.Name)
+			}
+		}
+	}
+
+	if c.firstUnexpected == nil {
+		c.firstUnexpected = &Request{
+			Name:   fmt.Sprintf("no expectations remaining - unexpected request at end"),
+			Method: method,
+			Header: nil, // not currently available
+			Url:    requestUrl,
+			Body:   requestBody,
+		}
+	}
+	return Expectation{}, errors.New("no expectations remaining - unexpected request at end")
+}
+
+func (c *VerifierImpl) AddExpectation(requestMatcher Request, response aurestclientapi.ParsedResponse, err error) {
+	c.expectations = append(c.expectations, Expectation{
+		Request: requestMatcher,
+		Response: ResponseOrError{
+			Response: response,
+			Error:    err,
+		},
+	})
+}
+
+func (c *VerifierImpl) FirstUnexpectedOrNil() *Request {
+	return c.firstUnexpected
+}