feat(validate): Parameters to methods will Validate automatically

lib/access.go

@@ -66,12 +66,6 @@ func (accessImpl) CreateAuthToken(scp scope, p *CreateAuthTokenParams) (string,
  grantee *profile.Profile
  err error
  )
- // TODO(b5): it'd be great if dispatch checked if input params implemented
- // a "validator" interface & auto-called validate *before* dispatching.
- // would save an HTTP call in RPC-style contexts.
- if err = p.Validate(); err != nil {
- return "", err
- }
 
  if p.GranteeProfileID != "" {
  id, err := profile.IDB58Decode(p.GranteeProfileID)

lib/access_test.go

@@ -28,3 +28,20 @@ func TestAccessCreateAuthToken(t *testing.T) {
  t.Fatal(err)
  }
 }
+
+func TestAccessValidationFailure(t *testing.T) {
+ ctx, cancel := context.WithCancel(context.Background())
+ defer cancel()
+ inst, cleanup := NewMemTestInstance(ctx, t)
+ defer cleanup()
+
+ p := &CreateAuthTokenParams{}
+ _, err := inst.Access().CreateAuthToken(ctx, p)
+ if err == nil {
+ t.Fatal("expected err but did not get one")
+ }
+ expectErr := "either grantee username or profile is required"
+ if err.Error() != expectErr {
+ t.Errorf("error mismatch, expect: %s, got: %s", expectErr, err)
+ }
+}

lib/dispatch.go

@@ -52,6 +52,14 @@ func (inst *Instance) Dispatch(ctx context.Context, method string, param interfa
  return nil, nil, fmt.Errorf("instance is nil, cannot dispatch")
  }
 
+ // If the input parameters has a Validate method, call it
+ if validator, ok := param.(ParamValidator); ok {
+ err = validator.Validate()
+ if err != nil {
+ return nil, nil, err
+ }
+ }
+
  // If the http rpc layer is engaged, use it to dispatch methods
  // This happens when another process is running `qri connect`
  if inst.http != nil {
@@ -150,6 +158,12 @@ func (inst *Instance) Dispatch(ctx context.Context, method string, param interfa
  return nil, nil, fmt.Errorf("method %q not found", method)
 }
 
+// ParamValidator may be implemented by method parameter structs, and if so
+// then Dispatch will validate the parameters are okay before calling anything
+type ParamValidator interface {
+ Validate() error
+}
+
 // NewInputParam takes a method name that has been registered, and constructs
 // an instance of that input parameter
 func (inst *Instance) NewInputParam(method string) interface{} {

lib/render.go

@@ -107,6 +107,7 @@ func (m *RenderMethods) RenderViz(ctx context.Context, p *RenderParams) ([]byte,
  return bres.Bytes(), nil
  }
 
+ // TODO(dustmop): Remove this once scope is used here, Dispatch will call Validate
  if err := p.Validate(); err != nil {
  return nil, err
  }

lib/render_test.go

@@ -239,3 +239,22 @@ func TestRenderReadme(t *testing.T) {
  t.Errorf("expected RenderReadme with both ref & dataset to error")
  }
 }
+
+func TestRenderValidationFailure(t *testing.T) {
+ runner := newRenderTestRunner(t, "render_readme")
+ defer runner.Delete()
+
+ params := RenderParams{
+ Ref: "peer/my_dataset",
+ Dataset: &dataset.Dataset{},
+ Format: "html",
+ }
+ _, err := runner.RenderMethods.RenderReadme(runner.Context, &params)
+ if err == nil {
+ t.Fatal("expected err but did not get one")
+ }
+ expectErr := "cannot provide both a reference and a dataset to render"
+ if err.Error() != expectErr {
+ t.Errorf("error mismatch, expect: %s, got: %s", expectErr, err)
+ }
+}

lib/transform_test.go

@@ -67,3 +67,18 @@ def transform(ds,ctx):
  t.Errorf("result mismatch. (-want +got):\n%s", diff)
  }
 }
+
+func TestApplyTransformValidationFailure(t *testing.T) {
+ tr := newTestRunner(t)
+ defer tr.Delete()
+
+ params := ApplyParams{}
+ _, err := tr.Instance.Transform().Apply(tr.Ctx, &params)
+ if err == nil {
+ t.Fatal("expected err but did not get one")
+ }
+ expectErr := "one or both of Reference, Transform are required"
+ if err.Error() != expectErr {
+ t.Errorf("error mismatch, expect: %s, got: %s", expectErr, err)
+ }
+}