Addressing review comments

Author: snej

go.mod

@@ -3,7 +3,6 @@ module github.com/couchbase/sg-bucket
 go 1.19
 
 require (
-	github.com/pkg/errors v0.9.1
 	github.com/robertkrimen/otto v0.0.0-20211024170158-b87d35c0b86f
 	github.com/snej/v8go v1.7.3
 	github.com/stretchr/testify v1.7.1
@@ -16,6 +15,7 @@ require (
 	github.com/golang/snappy v0.0.4 // indirect
 	github.com/google/uuid v1.3.0 // indirect
 	github.com/opentracing/opentracing-go v1.2.0 // indirect
+	github.com/pkg/errors v0.9.1 // indirect
 	github.com/pmezard/go-difflib v1.0.0 // indirect
 	golang.org/x/net v0.0.0-20220425223048-2871e0cb64e4 // indirect
 	golang.org/x/sync v0.0.0-20210220032951-036812b2e83c // indirect

js/otto_runner.go

@@ -13,10 +13,10 @@ package js
 import (
 	"context"
 	"encoding/json"
+	"errors"
 	"fmt"
 	"strconv"
 
-	"github.com/pkg/errors"
 	"github.com/robertkrimen/otto"
 
 	_ "github.com/robertkrimen/otto/underscore"

js/otto_vm.go

@@ -68,10 +68,10 @@ func (vm *ottoVM) getRunner(service *Service) (Runner, error) {
 		return nil, fmt.Errorf("the js.VM has been closed")
 	}
 	if vm.curRunner != nil {
-		panic("illegal access to v8VM: already has a v8Runner")
+		panic("illegal access to ottoVM: already has a ottoRunner")
 	}
 	if !vm.services.hasService(service) {
-		return nil, fmt.Errorf("unknown js.Service instance passed to VM")
+		return nil, fmt.Errorf("unknown js.Service instance passed to VM: %v", service)
 	}
 	if service.v8Init != nil {
 		return nil, fmt.Errorf("js.Service has custom initialization not supported by Otto")

js/v8_runner.go

@@ -15,11 +15,11 @@ package js
 import (
 	"context"
 	"encoding/json"
+	"errors"
 	"fmt"
 	"strings"
 	"time"
 
-	"github.com/pkg/errors"
 	v8 "github.com/snej/v8go" // Docs: https://pkg.go.dev/github.com/snej/v8go
 )
 
@@ -32,22 +32,25 @@ type V8Runner struct {
 	Client   any          // You can put whatever you want here, to point back to your state
 }
 
-func newV8Runner(vm *v8VM, template V8Template, id serviceID) (*V8Runner, error) {
+func newV8Runner(vm *v8VM, template V8Template, id serviceID) (runner *V8Runner, err error) {
 	// Create a V8 Context and run the setup script in it:
 	ctx := v8.NewContext(vm.iso, template.Global())
+	defer func() {
+		if err != nil {
+			ctx.Close()
+		}
+	}()
 	if _, err := vm.setupScript.Run(ctx); err != nil {
-		return nil, errors.Wrap(err, "Unexpected error in JavaScript initialization code")
+		return nil, fmt.Errorf("Unexpected error in JavaScript initialization code: %w", err)
 	}
 
 	// Now run the service's script, which returns the service's main function:
 	result, err := template.Script().Run(ctx)
 	if err != nil {
-		ctx.Close()
 		return nil, fmt.Errorf("JavaScript error initializing %s: %w", template.Name(), err)
 	}
 	mainFn, err := result.AsFunction()
 	if err != nil {
-		ctx.Close()
 		return nil, fmt.Errorf("%s's script did not return a function: %w", template.Name(), err)
 	}
 

js/v8_template.go

@@ -15,7 +15,6 @@ package js
 import (
 	"fmt"
 
-	"github.com/pkg/errors"
 	v8 "github.com/snej/v8go"
 )
 
@@ -114,7 +113,7 @@ func (t *V8BasicTemplate) NewCallback(callback TemplateCallback) *v8.FunctionTem
 			if v8Result, newValErr := runner.NewValue(result); err == nil {
 				return v8Result
 			} else {
-				err = errors.Wrap(newValErr, "Could not convert a callback's result to JavaScript")
+				err = fmt.Errorf("Could not convert a callback's result to JavaScript: %w", newValErr)
 			}
 		}
 		return v8Throw(vm.iso, err)

js/v8_utils.go

@@ -114,13 +114,7 @@ func newJSONString(ctx *v8.Context, val any) (*v8.Value, error) {
 // Returns an error back to a V8 caller.
 // Calls v8.Isolate.ThrowException, with the Go error's string as the message.
 func v8Throw(i *v8.Isolate, err error) *v8.Value {
-	var errStr string
-	// if httpErr, ok := err.(*base.HTTPError); ok {
-	// 	errStr = fmt.Sprintf("[%d] %s", httpErr.Status, httpErr.Message)
-	// } else {
-	errStr = err.Error()
-	// }
-	return i.ThrowException(newString(i, errStr))
+	return i.ThrowException(newString(i, err.Error()))
 }
 
 // Simple utility to wrap a function that returns a value and an error; returns just the value, panicking if there was an error.

js/v8_vm.go

@@ -18,7 +18,6 @@ import (
 	"sync"
 	"time"
 
-	"github.com/pkg/errors"
 	v8 "github.com/snej/v8go"
 )
 
@@ -123,7 +122,7 @@ func (vm *v8VM) release() {
 func (vm *v8VM) getTemplate(service *Service) (V8Template, error) {
 	var tmpl V8Template
 	if !vm.services.hasService(service) {
-		return nil, fmt.Errorf("unknown js.Service instance passed to VM")
+		return nil, fmt.Errorf("unknown js.Service instance passed to VM: %v", service)
 	}
 	if int(service.id) < len(vm.templates) {
 		tmpl = vm.templates[service.id]
@@ -134,7 +133,7 @@ func (vm *v8VM) getTemplate(service *Service) (V8Template, error) {
 			var err error
 			vm.setupScript, err = vm.iso.CompileUnboundScript(kSetupLoggingJS+kUnderscoreJS, "setupScript.js", v8.CompileOptions{})
 			if err != nil {
-				return nil, errors.Wrapf(err, "Couldn't compile setup script")
+				return nil, fmt.Errorf("Couldn't compile setup script: %w", err)
 			}
 		}
 

js/vmpool_test.go

@@ -68,7 +68,6 @@ func TestPoolsSequentially(t *testing.T) {
 
 func TestPoolsConcurrently(t *testing.T) {
 	maxProcs := runtime.GOMAXPROCS(0)
-	log.Printf("FYI, GOMAXPROCS = %d", maxProcs)
 	if !assert.GreaterOrEqual(t, maxProcs, 2, "Not enough OS threads available") {
 		return
 	}