Adds interface generation to service APIs

This change adds generation of interfaces for the service APIs. Each service now has a sub package <serviceName>iface which contains an interface for that service's operations. The interfaces can be used to facilitate unit testing with tools like mockery to generate mocks of service API.

fixes #88

internal/fixtures/integration/generate.go

@@ -66,7 +66,7 @@ var (
 
 var tplTestCase = template.Must(template.New("testcase").Parse(`
 func Test{{ .TestName }}(t *testing.T) {
-	client := {{ .API.PackageName }}.New(nil)
+	client := {{ .API.NewAPIGoCodeWithPkgName "nil" }}
 	resp, e := client.{{ .API.ExportableName .Operation }}({{ .InputCode }})
 	err := aws.Error(e)
 	_, _, _ = resp, e, err // avoid unused warnings

internal/model/api/api.go

@@ -46,6 +46,11 @@ func (a *API) PackageName() string {
 	return strings.ToLower(a.StructName())
 }
 
+// Returns the package name for the interface.
+func (a *API) InterfacePackageName() string {
+	return a.PackageName() + "iface"
+}
+
 var nameRegex = regexp.MustCompile(`^Amazon|AWS\s*|\(.*|\s+|\W+`)
 
 // StructName returns the service struct name for a given service
@@ -281,3 +286,43 @@ func (a *API) ExampleGoCode() string {
 	)
 	return util.GoFmt(code)
 }
+
+var tplInterface = template.Must(template.New("interface").Parse(`
+type {{ .StructName }} interface {
+    {{ range $_, $o := .OperationList }}
+        {{ $o.InterfaceSignature }}
+    {{ end }}
+}
+`))
+
+// Returns the go code for the service's API operations as an interface{}.
+// Assumes that the interface is being created in a different package than
+// the service API's package.
+func (a *API) InterfaceGoCode() string {
+	a.resetImports()
+	a.imports = map[string]bool{
+		"github.com/awslabs/aws-sdk-go/service/" + a.PackageName(): true,
+	}
+
+	var buf bytes.Buffer
+	err := tplInterface.Execute(&buf, &struct {
+		StructName    string
+		OperationList []*Operation
+	}{
+		StructName:    a.StructName() + "API",
+		OperationList: a.OperationList(),
+	})
+
+	if err != nil {
+		panic(err)
+	}
+
+	code := a.importsGoCode() + strings.TrimSpace(buf.String())
+	return util.GoFmt(code)
+}
+
+// Returns a string of instantiating the API prefixed with its package name.
+// Takes a string depicting the Config.
+func (a *API) NewAPIGoCodeWithPkgName(cfg string) string {
+	return fmt.Sprintf("%s.New(%s)", a.PackageName(), cfg)
+}

internal/model/api/operation.go

@@ -89,9 +89,24 @@ func (o *Operation) GoCode() string {
 	return strings.TrimSpace(util.GoFmt(buf.String()))
 }
 
+var tplInfSig = template.Must(template.New("opsig").Parse(`
+{{ .ExportedName }}({{ .InputRef.GoTypeWithPkgName }}) ({{ .OutputRef.GoTypeWithPkgName }}, error)
+`))
+
+// Returns a string representing the Operation's interface{} functional signature.
+func (o *Operation) InterfaceSignature() string {
+	var buf bytes.Buffer
+	err := tplInfSig.Execute(&buf, o)
+	if err != nil {
+		panic(err)
+	}
+
+	return strings.TrimSpace(util.GoFmt(buf.String()))
+}
+
 var tplExample = template.Must(template.New("operationExample").Parse(`
 func Example{{ .API.StructName }}_{{ .ExportedName }}() {
-	svc := {{ .API.PackageName }}.New(nil)
+	svc := {{ .API.NewAPIGoCodeWithPkgName "nil" }}
 
 	{{ .ExampleInput }}
 	resp, err := svc.{{ .ExportedName }}(params)

internal/model/api/shape.go

@@ -70,9 +70,44 @@ func (s *Shape) MemberNames() []string {
 	return names
 }
 
+// Returns a shape's type as a string with the package name in <packageName>.<type> format.
+// package naming only applies to structures.
+func (s *Shape) GoTypeWithPkgName() string {
+	return goType(s, true)
+}
+
+// Returns a shape's Go type
 func (s *Shape) GoType() string {
+	return goType(s, false)
+}
+
+// Returns a shape ref's Go type.
+func (ref *ShapeRef) GoType() string {
+	if ref.Shape == nil {
+		panic(fmt.Errorf("missing shape definition on reference for %#v", ref))
+	}
+
+	return ref.Shape.GoType()
+}
+
+// Returns a shape's type as a string with the package name in <packageName>.<type> format.
+// package naming only applies to structures.
+func (ref *ShapeRef) GoTypeWithPkgName() string {
+	if ref.Shape == nil {
+		panic(fmt.Errorf("missing shape definition on reference for %#v", ref))
+	}
+
+	return ref.Shape.GoTypeWithPkgName()
+}
+
+// Returns a string version of the Shape's type.
+// If withPkgName is true, the package name will be added as a prefix
+func goType(s *Shape, withPkgName bool) string {
 	switch s.Type {
 	case "structure":
+		if withPkgName {
+			return fmt.Sprintf("*%s.%s", s.API.PackageName(), s.ShapeName)
+		}
 		return "*" + s.ShapeName
 	case "map":
 		return "*map[string]" + s.ValueRef.GoType()
@@ -96,14 +131,6 @@ func (s *Shape) GoType() string {
 	}
 }
 
-func (ref *ShapeRef) GoType() string {
-	if ref.Shape == nil {
-		panic(fmt.Errorf("missing shape definition on reference for %#v", ref))
-	}
-
-	return ref.Shape.GoType()
-}
-
 func (s *Shape) GoTypeElem() string {
 	t := s.GoType()
 	if strings.HasPrefix(t, "*") {

internal/model/cli/gen-api/main.go

@@ -39,6 +39,7 @@ func newGenerateInfo(modelFile, svcPath string) *generateInfo {
 	// ensure the directory exists
 	pkgDir := filepath.Join(svcPath, g.API.PackageName())
 	os.MkdirAll(pkgDir, 0775)
+	os.MkdirAll(filepath.Join(pkgDir, g.API.InterfacePackageName()), 0775)
 
 	g.PackageDir = pkgDir
 
@@ -105,6 +106,7 @@ func main() {
 					g.writeAPIFile()
 					g.writeExamplesFile()
 					g.writeServiceFile()
+					g.writeInterfaceFile()
 				}
 			}
 		}()
@@ -122,6 +124,11 @@ func (g *generateInfo) writeServiceFile() {
 	ioutil.WriteFile(file, []byte("package "+g.API.PackageName()+"\n\n"+g.API.ServiceGoCode()), 0664)
 }
 
+func (g *generateInfo) writeInterfaceFile() {
+	file := filepath.Join(g.PackageDir, g.API.InterfacePackageName(), "interface.go")
+	ioutil.WriteFile(file, []byte("package "+g.API.InterfacePackageName()+"\n\n"+g.API.InterfaceGoCode()), 0664)
+}
+
 const note = "// THIS FILE IS AUTOMATICALLY GENERATED. DO NOT EDIT."
 
 func (g *generateInfo) writeAPIFile() {

service/autoscaling/autoscalingiface/interface.go

@@ -0,0 +1,97 @@
+package autoscalingiface
+
+import (
+	"github.com/awslabs/aws-sdk-go/service/autoscaling"
+)
+
+type AutoScalingAPI interface {
+	AttachInstances(*autoscaling.AttachInstancesInput) (*autoscaling.AttachInstancesOutput, error)
+
+	CompleteLifecycleAction(*autoscaling.CompleteLifecycleActionInput) (*autoscaling.CompleteLifecycleActionOutput, error)
+
+	CreateAutoScalingGroup(*autoscaling.CreateAutoScalingGroupInput) (*autoscaling.CreateAutoScalingGroupOutput, error)
+
+	CreateLaunchConfiguration(*autoscaling.CreateLaunchConfigurationInput) (*autoscaling.CreateLaunchConfigurationOutput, error)
+
+	CreateOrUpdateTags(*autoscaling.CreateOrUpdateTagsInput) (*autoscaling.CreateOrUpdateTagsOutput, error)
+
+	DeleteAutoScalingGroup(*autoscaling.DeleteAutoScalingGroupInput) (*autoscaling.DeleteAutoScalingGroupOutput, error)
+
+	DeleteLaunchConfiguration(*autoscaling.DeleteLaunchConfigurationInput) (*autoscaling.DeleteLaunchConfigurationOutput, error)
+
+	DeleteLifecycleHook(*autoscaling.DeleteLifecycleHookInput) (*autoscaling.DeleteLifecycleHookOutput, error)
+
+	DeleteNotificationConfiguration(*autoscaling.DeleteNotificationConfigurationInput) (*autoscaling.DeleteNotificationConfigurationOutput, error)
+
+	DeletePolicy(*autoscaling.DeletePolicyInput) (*autoscaling.DeletePolicyOutput, error)
+
+	DeleteScheduledAction(*autoscaling.DeleteScheduledActionInput) (*autoscaling.DeleteScheduledActionOutput, error)
+
+	DeleteTags(*autoscaling.DeleteTagsInput) (*autoscaling.DeleteTagsOutput, error)
+
+	DescribeAccountLimits(*autoscaling.DescribeAccountLimitsInput) (*autoscaling.DescribeAccountLimitsOutput, error)
+
+	DescribeAdjustmentTypes(*autoscaling.DescribeAdjustmentTypesInput) (*autoscaling.DescribeAdjustmentTypesOutput, error)
+
+	DescribeAutoScalingGroups(*autoscaling.DescribeAutoScalingGroupsInput) (*autoscaling.DescribeAutoScalingGroupsOutput, error)
+
+	DescribeAutoScalingInstances(*autoscaling.DescribeAutoScalingInstancesInput) (*autoscaling.DescribeAutoScalingInstancesOutput, error)
+
+	DescribeAutoScalingNotificationTypes(*autoscaling.DescribeAutoScalingNotificationTypesInput) (*autoscaling.DescribeAutoScalingNotificationTypesOutput, error)
+
+	DescribeLaunchConfigurations(*autoscaling.DescribeLaunchConfigurationsInput) (*autoscaling.DescribeLaunchConfigurationsOutput, error)
+
+	DescribeLifecycleHookTypes(*autoscaling.DescribeLifecycleHookTypesInput) (*autoscaling.DescribeLifecycleHookTypesOutput, error)
+
+	DescribeLifecycleHooks(*autoscaling.DescribeLifecycleHooksInput) (*autoscaling.DescribeLifecycleHooksOutput, error)
+
+	DescribeMetricCollectionTypes(*autoscaling.DescribeMetricCollectionTypesInput) (*autoscaling.DescribeMetricCollectionTypesOutput, error)
+
+	DescribeNotificationConfigurations(*autoscaling.DescribeNotificationConfigurationsInput) (*autoscaling.DescribeNotificationConfigurationsOutput, error)
+
+	DescribePolicies(*autoscaling.DescribePoliciesInput) (*autoscaling.DescribePoliciesOutput, error)
+
+	DescribeScalingActivities(*autoscaling.DescribeScalingActivitiesInput) (*autoscaling.DescribeScalingActivitiesOutput, error)
+
+	DescribeScalingProcessTypes(*autoscaling.DescribeScalingProcessTypesInput) (*autoscaling.DescribeScalingProcessTypesOutput, error)
+
+	DescribeScheduledActions(*autoscaling.DescribeScheduledActionsInput) (*autoscaling.DescribeScheduledActionsOutput, error)
+
+	DescribeTags(*autoscaling.DescribeTagsInput) (*autoscaling.DescribeTagsOutput, error)
+
+	DescribeTerminationPolicyTypes(*autoscaling.DescribeTerminationPolicyTypesInput) (*autoscaling.DescribeTerminationPolicyTypesOutput, error)
+
+	DetachInstances(*autoscaling.DetachInstancesInput) (*autoscaling.DetachInstancesOutput, error)
+
+	DisableMetricsCollection(*autoscaling.DisableMetricsCollectionInput) (*autoscaling.DisableMetricsCollectionOutput, error)
+
+	EnableMetricsCollection(*autoscaling.EnableMetricsCollectionInput) (*autoscaling.EnableMetricsCollectionOutput, error)
+
+	EnterStandby(*autoscaling.EnterStandbyInput) (*autoscaling.EnterStandbyOutput, error)
+
+	ExecutePolicy(*autoscaling.ExecutePolicyInput) (*autoscaling.ExecutePolicyOutput, error)
+
+	ExitStandby(*autoscaling.ExitStandbyInput) (*autoscaling.ExitStandbyOutput, error)
+
+	PutLifecycleHook(*autoscaling.PutLifecycleHookInput) (*autoscaling.PutLifecycleHookOutput, error)
+
+	PutNotificationConfiguration(*autoscaling.PutNotificationConfigurationInput) (*autoscaling.PutNotificationConfigurationOutput, error)
+
+	PutScalingPolicy(*autoscaling.PutScalingPolicyInput) (*autoscaling.PutScalingPolicyOutput, error)
+
+	PutScheduledUpdateGroupAction(*autoscaling.PutScheduledUpdateGroupActionInput) (*autoscaling.PutScheduledUpdateGroupActionOutput, error)
+
+	RecordLifecycleActionHeartbeat(*autoscaling.RecordLifecycleActionHeartbeatInput) (*autoscaling.RecordLifecycleActionHeartbeatOutput, error)
+
+	ResumeProcesses(*autoscaling.ScalingProcessQuery) (*autoscaling.ResumeProcessesOutput, error)
+
+	SetDesiredCapacity(*autoscaling.SetDesiredCapacityInput) (*autoscaling.SetDesiredCapacityOutput, error)
+
+	SetInstanceHealth(*autoscaling.SetInstanceHealthInput) (*autoscaling.SetInstanceHealthOutput, error)
+
+	SuspendProcesses(*autoscaling.ScalingProcessQuery) (*autoscaling.SuspendProcessesOutput, error)
+
+	TerminateInstanceInAutoScalingGroup(*autoscaling.TerminateInstanceInAutoScalingGroupInput) (*autoscaling.TerminateInstanceInAutoScalingGroupOutput, error)
+
+	UpdateAutoScalingGroup(*autoscaling.UpdateAutoScalingGroupInput) (*autoscaling.UpdateAutoScalingGroupOutput, error)
+}

service/cloudformation/cloudformationiface/interface.go

@@ -0,0 +1,41 @@
+package cloudformationiface
+
+import (
+	"github.com/awslabs/aws-sdk-go/service/cloudformation"
+)
+
+type CloudFormationAPI interface {
+	CancelUpdateStack(*cloudformation.CancelUpdateStackInput) (*cloudformation.CancelUpdateStackOutput, error)
+
+	CreateStack(*cloudformation.CreateStackInput) (*cloudformation.CreateStackOutput, error)
+
+	DeleteStack(*cloudformation.DeleteStackInput) (*cloudformation.DeleteStackOutput, error)
+
+	DescribeStackEvents(*cloudformation.DescribeStackEventsInput) (*cloudformation.DescribeStackEventsOutput, error)
+
+	DescribeStackResource(*cloudformation.DescribeStackResourceInput) (*cloudformation.DescribeStackResourceOutput, error)
+
+	DescribeStackResources(*cloudformation.DescribeStackResourcesInput) (*cloudformation.DescribeStackResourcesOutput, error)
+
+	DescribeStacks(*cloudformation.DescribeStacksInput) (*cloudformation.DescribeStacksOutput, error)
+
+	EstimateTemplateCost(*cloudformation.EstimateTemplateCostInput) (*cloudformation.EstimateTemplateCostOutput, error)
+
+	GetStackPolicy(*cloudformation.GetStackPolicyInput) (*cloudformation.GetStackPolicyOutput, error)
+
+	GetTemplate(*cloudformation.GetTemplateInput) (*cloudformation.GetTemplateOutput, error)
+
+	GetTemplateSummary(*cloudformation.GetTemplateSummaryInput) (*cloudformation.GetTemplateSummaryOutput, error)
+
+	ListStackResources(*cloudformation.ListStackResourcesInput) (*cloudformation.ListStackResourcesOutput, error)
+
+	ListStacks(*cloudformation.ListStacksInput) (*cloudformation.ListStacksOutput, error)
+
+	SetStackPolicy(*cloudformation.SetStackPolicyInput) (*cloudformation.SetStackPolicyOutput, error)
+
+	SignalResource(*cloudformation.SignalResourceInput) (*cloudformation.SignalResourceOutput, error)
+
+	UpdateStack(*cloudformation.UpdateStackInput) (*cloudformation.UpdateStackOutput, error)
+
+	ValidateTemplate(*cloudformation.ValidateTemplateInput) (*cloudformation.ValidateTemplateOutput, error)
+}

service/cloudfront/cloudfrontiface/interface.go

@@ -0,0 +1,49 @@
+package cloudfrontiface
+
+import (
+	"github.com/awslabs/aws-sdk-go/service/cloudfront"
+)
+
+type CloudFrontAPI interface {
+	CreateCloudFrontOriginAccessIdentity(*cloudfront.CreateCloudFrontOriginAccessIdentityInput) (*cloudfront.CreateCloudFrontOriginAccessIdentityOutput, error)
+
+	CreateDistribution(*cloudfront.CreateDistributionInput) (*cloudfront.CreateDistributionOutput, error)
+
+	CreateInvalidation(*cloudfront.CreateInvalidationInput) (*cloudfront.CreateInvalidationOutput, error)
+
+	CreateStreamingDistribution(*cloudfront.CreateStreamingDistributionInput) (*cloudfront.CreateStreamingDistributionOutput, error)
+
+	DeleteCloudFrontOriginAccessIdentity(*cloudfront.DeleteCloudFrontOriginAccessIdentityInput) (*cloudfront.DeleteCloudFrontOriginAccessIdentityOutput, error)
+
+	DeleteDistribution(*cloudfront.DeleteDistributionInput) (*cloudfront.DeleteDistributionOutput, error)
+
+	DeleteStreamingDistribution(*cloudfront.DeleteStreamingDistributionInput) (*cloudfront.DeleteStreamingDistributionOutput, error)
+
+	GetCloudFrontOriginAccessIdentity(*cloudfront.GetCloudFrontOriginAccessIdentityInput) (*cloudfront.GetCloudFrontOriginAccessIdentityOutput, error)
+
+	GetCloudFrontOriginAccessIdentityConfig(*cloudfront.GetCloudFrontOriginAccessIdentityConfigInput) (*cloudfront.GetCloudFrontOriginAccessIdentityConfigOutput, error)
+
+	GetDistribution(*cloudfront.GetDistributionInput) (*cloudfront.GetDistributionOutput, error)
+
+	GetDistributionConfig(*cloudfront.GetDistributionConfigInput) (*cloudfront.GetDistributionConfigOutput, error)
+
+	GetInvalidation(*cloudfront.GetInvalidationInput) (*cloudfront.GetInvalidationOutput, error)
+
+	GetStreamingDistribution(*cloudfront.GetStreamingDistributionInput) (*cloudfront.GetStreamingDistributionOutput, error)
+
+	GetStreamingDistributionConfig(*cloudfront.GetStreamingDistributionConfigInput) (*cloudfront.GetStreamingDistributionConfigOutput, error)
+
+	ListCloudFrontOriginAccessIdentities(*cloudfront.ListCloudFrontOriginAccessIdentitiesInput) (*cloudfront.ListCloudFrontOriginAccessIdentitiesOutput, error)
+
+	ListDistributions(*cloudfront.ListDistributionsInput) (*cloudfront.ListDistributionsOutput, error)
+
+	ListInvalidations(*cloudfront.ListInvalidationsInput) (*cloudfront.ListInvalidationsOutput, error)
+
+	ListStreamingDistributions(*cloudfront.ListStreamingDistributionsInput) (*cloudfront.ListStreamingDistributionsOutput, error)
+
+	UpdateCloudFrontOriginAccessIdentity(*cloudfront.UpdateCloudFrontOriginAccessIdentityInput) (*cloudfront.UpdateCloudFrontOriginAccessIdentityOutput, error)
+
+	UpdateDistribution(*cloudfront.UpdateDistributionInput) (*cloudfront.UpdateDistributionOutput, error)
+
+	UpdateStreamingDistribution(*cloudfront.UpdateStreamingDistributionInput) (*cloudfront.UpdateStreamingDistributionOutput, error)
+}