Add error middleware (#35)

* Add error middleware

if there is a problem marshalling and writing json the error
middleware handles mapping the context errors to a result error
and returning json as a 500

* add service input

define a method for exposing a request body struct and auto marshaling 
into the given struct. The struct is then stored on the req object and 
returned as a param to the config handler

examples/main.go

@@ -23,6 +23,7 @@ import (
 	_ "github.com/simiancreative/simiango/examples/services/param"
 	_ "github.com/simiancreative/simiango/examples/services/pg"
 	_ "github.com/simiancreative/simiango/examples/services/rabbit"
+	_ "github.com/simiancreative/simiango/examples/services/request-receiver"
 	_ "github.com/simiancreative/simiango/examples/services/sample"
 	_ "github.com/simiancreative/simiango/examples/services/stream"
 	_ "github.com/simiancreative/simiango/examples/services/unsafe"

examples/services/error/error.go

@@ -3,10 +3,14 @@ package error
 import (
 	"fmt"
 
+	"github.com/jackc/pgtype"
+
 	"github.com/simiancreative/simiango/server"
 	"github.com/simiancreative/simiango/service"
 )
 
+// JUST AN ERROR
+
 var Config = service.Config{
 	Kind:   service.DIRECT,
 	Method: "GET",
@@ -18,8 +22,26 @@ func direct(req service.Req) (interface{}, error) {
 	return nil, fmt.Errorf("this is an error")
 }
 
+// BAD JSON
+
+var badJsonConfig = service.Config{
+	Kind:   service.DIRECT,
+	Method: "GET",
+	Path:   "/error/bad-json",
+	Direct: badJson,
+}
+
+type Product struct {
+	ID   string       `json:"id"   db:"id"`
+	Meta pgtype.JSONB `json:"meta" db:"meta"`
+}
+
+func badJson(_ service.Req) (interface{}, error) {
+	return Product{}, nil
+}
+
 // dont forget to import your package in your main.go for initialization
 // _ "path/to/project/direct"
 func init() {
-	server.AddService(Config)
+	server.AddServices([]service.Config{Config, badJsonConfig})
 }

examples/services/request-receiver/index.go

@@ -0,0 +1,31 @@
+package requestreceiver
+
+import (
+	"github.com/simiancreative/simiango/server"
+	"github.com/simiancreative/simiango/service"
+)
+
+var Config = service.Config{
+	Kind:   service.DIRECT,
+	Method: "POST",
+	Path:   "/request-receiver",
+	Direct: direct,
+	Input:  input,
+}
+
+type Product struct {
+	ID   string `json:"id"   db:"id"`
+	Name string `json:"name" db:"name"`
+}
+
+func direct(req service.Req) (interface{}, error) {
+	return req.Input, nil
+}
+
+func input() interface{} {
+	return &Product{}
+}
+
+func init() {
+	server.AddService(Config)
+}

go.mod

@@ -20,6 +20,7 @@ require (
 	github.com/go-sql-driver/mysql v1.6.0
 	github.com/golang-jwt/jwt v3.2.2+incompatible
 	github.com/google/uuid v1.3.0
+	github.com/jackc/pgtype v1.14.3
 	github.com/jackc/pgx v3.6.2+incompatible
 	github.com/jedib0t/go-pretty/v6 v6.3.7
 	github.com/jmoiron/sqlx v1.3.5
@@ -35,7 +36,7 @@ require (
 	github.com/sirupsen/logrus v1.9.0
 	github.com/spf13/cobra v1.5.0
 	github.com/stretchr/testify v1.8.3
-	golang.org/x/crypto v0.17.0
+	golang.org/x/crypto v0.20.0
 	gopkg.in/validator.v2 v2.0.1
 )
 
@@ -59,6 +60,7 @@ require (
 	github.com/golang/gddo v0.0.0-20200310004957-95ce5a452273 // indirect
 	github.com/golang/protobuf v1.5.2 // indirect
 	github.com/inconshreveable/mousetrap v1.0.0 // indirect
+	github.com/jackc/pgio v1.0.0 // indirect
 	github.com/json-iterator/go v1.1.12 // indirect
 	github.com/kballard/go-shellquote v0.0.0-20180428030007-95032a82bc51 // indirect
 	github.com/klauspost/compress v1.16.0 // indirect
@@ -89,20 +91,16 @@ require (
 	github.com/ugorji/go/codec v1.2.11 // indirect
 	github.com/yuin/gopher-lua v0.0.0-20210529063254-f4c35e4016d9 // indirect
 	golang.org/x/arch v0.3.0 // indirect
-	golang.org/x/sys v0.15.0 // indirect
-	golang.org/x/term v0.15.0 // indirect
+	golang.org/x/sys v0.17.0 // indirect
+	golang.org/x/term v0.17.0 // indirect
 	golang.org/x/text v0.14.0 // indirect
 	google.golang.org/protobuf v1.30.0 // indirect
 	gopkg.in/yaml.v3 v3.0.1 // indirect
 )
 
 require (
-	github.com/cockroachdb/apd v1.1.0 // indirect
 	github.com/getsentry/sentry-go v0.27.0
 	github.com/gin-gonic/contrib v0.0.0-20201101042839-6a891bf89f19 // indirect
-	github.com/gofrs/uuid v4.0.0+incompatible // indirect
 	github.com/jackc/fake v0.0.0-20150926172116-812a484cc733 // indirect
-	github.com/lib/pq v1.10.2 // indirect
-	github.com/shopspring/decimal v1.2.0 // indirect
-	golang.org/x/net v0.17.0 // indirect
+	golang.org/x/net v0.21.0 // indirect
 )

meta/rescue.go

@@ -63,7 +63,7 @@ func recoverGinPanic(c *gin.Context, buildResp func(*gin.Context, map[string]int
 		}
 
 		id, _ := c.Get("request_id")
-		stack := stack()
+		stack := Stack()
 		httpRequest, _ := httputil.DumpRequest(c.Request, false)
 		headers := strings.Split(string(httpRequest), "\r\n")
 		for idx, header := range headers {
@@ -98,7 +98,7 @@ func recoverGinPanic(c *gin.Context, buildResp func(*gin.Context, map[string]int
 	}
 }
 
-func stack() []string {
+func Stack() []string {
 	skip := 3
 	result := []string{}
 	// As we loop, we open files and read them. These variables record the currently
@@ -131,7 +131,7 @@ func stack() []string {
 
 func stackAsBuf() []byte {
 	buf := new(bytes.Buffer) // the returned data
-	lines := stack()
+	lines := Stack()
 
 	for _, line := range lines {
 		fmt.Fprint(buf, line)

meta/rescue_test.go

@@ -85,7 +85,7 @@ func TestRecoverGinPanic_BrokenPipe(t *testing.T) {
 }
 
 func TestStack(t *testing.T) {
-	stack := stack()
+	stack := Stack()
 	if len(stack) == 0 {
 		t.Fatalf("Expected stack trace, got empty")
 	}

monitoring/sentry/sentry.go

@@ -9,7 +9,6 @@ import (
 	"github.com/gin-gonic/gin"
 
 	"github.com/simiancreative/simiango/logger"
-	"github.com/simiancreative/simiango/service"
 )
 
 func Enable() {
@@ -47,7 +46,7 @@ func RecoverAndThrow() {
 }
 
 // CaptureError is a helper function to capture an error and return it so the caller can handle it
-func GinCaptureError(c *gin.Context, err *service.ResultError) *service.ResultError {
+func GinCaptureError(c *gin.Context, err error) error {
 	hub := sentrygin.GetHubFromContext(c)
 
 	if hub == nil {

monitoring/sentry/sentry_scope_test.go

@@ -0,0 +1,46 @@
+package sentry_test
+
+import (
+	"errors"
+	"net/http/httptest"
+	"testing"
+
+	sentrygin "github.com/getsentry/sentry-go"
+	"github.com/gin-gonic/gin"
+	"github.com/stretchr/testify/assert"
+
+	"github.com/simiancreative/simiango/monitoring/sentry"
+)
+
+func TestGinCaptureError(t *testing.T) {
+	t.Run("sentryScopeFunc is not ok", func(t *testing.T) {
+		gin.SetMode(gin.TestMode)
+		c, _ := gin.CreateTestContext(httptest.NewRecorder())
+
+		hub := sentrygin.CurrentHub()
+		c.Set("sentry", hub)
+
+		err := errors.New("test error")
+		returnedErr := sentry.GinCaptureError(c, err)
+
+		assert.Equal(t, err, returnedErr)
+	})
+}
+
+func TestScopeFunctionError(t *testing.T) {
+	t.Run("scopeFunction is not ok", func(t *testing.T) {
+		gin.SetMode(gin.TestMode)
+		c, _ := gin.CreateTestContext(httptest.NewRecorder())
+
+		hub := sentrygin.CurrentHub()
+		c.Set("sentry", hub)
+
+		// Set a non-function value for "sentryScopeFunc"
+		c.Set("sentryScopeFunc", "not a function")
+
+		err := errors.New("test error")
+		returnedErr := sentry.GinCaptureError(c, err)
+
+		assert.Equal(t, err, returnedErr)
+	})
+}

server/errors.go

@@ -0,0 +1,30 @@
+package server
+
+import (
+	"net/http"
+
+	"github.com/gin-gonic/gin"
+
+	"github.com/simiancreative/simiango/service"
+)
+
+func errorMiddleware(c *gin.Context) {
+	c.Next()
+
+	if len(c.Errors) == 0 {
+		return
+	}
+
+	resp := service.ResultError{
+		Status:  http.StatusInternalServerError,
+		Message: "Internal Server Error",
+	}
+
+	for _, err := range c.Errors {
+		resp.Reasons = append(resp.Reasons, map[string]interface{}{
+			"error": err.Error(),
+		})
+	}
+
+	c.JSON(http.StatusInternalServerError, resp)
+}

server/errors_test.go

@@ -0,0 +1,43 @@
+package server
+
+import (
+	"net/http"
+	"net/http/httptest"
+	"testing"
+
+	"github.com/gin-gonic/gin"
+	"github.com/stretchr/testify/assert"
+
+	"github.com/simiancreative/simiango/service"
+)
+
+func TestErrorMiddleware(t *testing.T) {
+	// Happy path
+	t.Run("no errors", func(t *testing.T) {
+		gin.SetMode(gin.TestMode)
+		w := httptest.NewRecorder()
+		c, _ := gin.CreateTestContext(w)
+
+		errorMiddleware(c)
+
+		assert.Equal(t, http.StatusOK, w.Code)
+		assert.Equal(t, "", w.Body.String())
+	})
+
+	// Error path
+	t.Run("with errors", func(t *testing.T) {
+		gin.SetMode(gin.TestMode)
+		w := httptest.NewRecorder()
+		c, _ := gin.CreateTestContext(w)
+
+		c.Error(gin.Error{
+			Err:  &service.ResultError{},
+			Type: gin.ErrorTypePublic,
+		})
+
+		errorMiddleware(c)
+
+		assert.Equal(t, http.StatusInternalServerError, w.Code)
+		assert.Contains(t, w.Body.String(), "Internal Server Error")
+	})
+}

server/server.go

@@ -25,6 +25,7 @@ func Init() {
 		servertiming.Middleware(),
 		JSONLogMiddleware,
 		meta.GinRecovery(handleRecovery),
+		errorMiddleware,
 	)
 }
 

server/service.go

@@ -26,13 +26,13 @@ func handleService(config service.Config) gin.HandlerFunc {
 		var result interface{}
 		var err *service.ResultError
 
-		value, ok := kinds[config.Kind]
+		handler, ok := kinds[config.Kind]
 		if !ok {
 			result, err = handleDefault(config, req)
 		}
 
 		if ok {
-			result, err = value(config, req)
+			result, err = handler(config, req)
 		}
 
 		timer.Stop()

server/service_handle_direct.go

@@ -17,6 +17,10 @@ func handleDirect(config service.Config, req service.Req) (interface{}, *service
 		}
 	}
 
+	if err := parseBody(config, &req); err != nil {
+		return nil, handleError(err)
+	}
+
 	result, err := config.Direct(req)
 
 	if err == nil && result == nil {
@@ -41,7 +45,6 @@ func handleDirectAuth(
 	}
 
 	err = config.Auth(req)
-
 	if err != nil {
 		err = fmt.Errorf("Authentication Failed: %v", err.Error())
 		resultErr := service.ToResultError(err, "service auth failed", 401)

server/utils.go

@@ -29,6 +29,23 @@ func rawBody(source io.ReadCloser) []byte {
 	return []byte(reqBody)
 }
 
+func parseBody(config service.Config, req *service.Req) error {
+	if config.Input == nil {
+		return nil
+	}
+
+	input := config.Input()
+
+	err := service.ParseBody(req.Body, input)
+	if err != nil {
+		return err
+	}
+
+	req.Input = input
+
+	return nil
+}
+
 func parseParams(params gin.Params, url *url.URL) service.RawParams {
 	parsedParams := service.RawParams{}
 
@@ -61,7 +78,7 @@ func handleErrorResp(err *service.ResultError, c *gin.Context) *service.ResultEr
 		return err
 	}
 
-	return sentry.GinCaptureError(c, err)
+	return sentry.GinCaptureError(c, err).(*service.ResultError)
 }
 
 func handleError(err error) *service.ResultError {