Make host cap function call work with arguments

builtin/myplugin/host/alwaystrue.go

@@ -27,7 +27,7 @@ func (h *AlwaysTrueHost) Detect() bool {
 }
 
 func (h *AlwaysTrueHost) InitializeCapabilities() (err error) {
-	err = h.RegisterCapability("write_hello", cap.WriteHelloFunc())
+	err = h.RegisterCapability("write_hello", cap.WriteHello)
 	return
 }
 

builtin/myplugin/host/cap/write_hello.go

@@ -2,15 +2,12 @@ package cap
 
 import (
 	"io/ioutil"
+
+	"github.com/hashicorp/vagrant-plugin-sdk/terminal"
 )
 
-func WriteHelloFunc() interface{} {
+func WriteHello(ui terminal.UI) error {
-	return WriteHello
+	data := []byte("Hello from the write hello capability, compliments of the AlwaysTrue Host")
-}
-
-// func WriteHello(trm terminal.UI) error {
-func WriteHello() error {
-	data := []byte("hello from the always true host plugin\n")
 	ioutil.WriteFile("/tmp/hello", data, 0644)
 	return nil
 }

builtin/otherplugin/command.go

@@ -162,7 +162,11 @@ func (c *Command) ExecuteUseHostPlugin(trm terminal.UI, host plugincore.Host) in
 	ok := host.HasCapability("write_hello")
 	if ok {
 		trm.Output("Writing to file using `write_hello` capability")
-		host.Capability("write_hello", argmapper.Typed(trm))
+		_, err := host.Capability("write_hello", argmapper.Typed("hehehe i'm a string"), argmapper.Typed(trm))
+		if err != nil {
+			trm.Output("Error!")
+			return 1
+		}
 	} else {
 		trm.Output("no `write_hello` capability found")
 	}

internal/core/basis.go

@@ -18,7 +18,6 @@ import (
 	"github.com/hashicorp/vagrant-plugin-sdk/component"
 	"github.com/hashicorp/vagrant-plugin-sdk/core"
 	"github.com/hashicorp/vagrant-plugin-sdk/datadir"
-	"github.com/hashicorp/vagrant-plugin-sdk/internal-shared/componentprotomappers"
 	"github.com/hashicorp/vagrant-plugin-sdk/internal-shared/protomappers"
 	"github.com/hashicorp/vagrant-plugin-sdk/proto/vagrant_plugin_sdk"
 	"github.com/hashicorp/vagrant-plugin-sdk/terminal"
@@ -96,8 +95,7 @@ func NewBasis(ctx context.Context, opts ...BasisOption) (b *Basis, err error) {
 
 	// If the mappers aren't already set, load known mappers
 	if len(b.mappers) == 0 {
-		mappers := append(protomappers.All, componentprotomappers.All...)
+		b.mappers, err = argmapper.NewFuncList(protomappers.All,
-		b.mappers, err = argmapper.NewFuncList(mappers,
 			argmapper.Logger(b.logger),
 		)
 		if err != nil {

internal/core/target.go

@@ -168,6 +168,16 @@ func (t *Target) Run(ctx context.Context, task *vagrant_server.Task) (err error)
 
 	host, _ := t.project.Host()
 
+	_, err = t.callDynamicFunc(
+		ctx,
+		t.logger,
+		(interface{})(nil),
+		nil,
+		host.(component.Host).CapabilityFunc("write_hello"),
+		argmapper.Typed(t.ui),
+	)
+	// host.Capability("write_hello", argmapper.Typed(t.ui))
+
 	result, err := t.callDynamicFunc(
 		ctx,
 		t.logger,